dynamically diagnosing the human periodontium and the dental implant-bone interface

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Resonance frequency analysis and damping capacity assessment. Part I: an in vitro study on measurement reliability and a method of comparison in the determination of primary dental implant stability
LACHMANN S, JAGER B, AXMANN D, GOMEZ-ROMAN G, GROTEN M, WEBER H.,     Department of Prosthodontics, University of Tubingen, Tubingen, Germany.
Clin Oral Implants Res. 2006 Feb;17(1):75-9.
Evaluation Study
OBJECTIVES: The aims of this in vitro study were to evaluate reliability of the Osstell and Periotest devices in the assessment of implant stability and to perform a method comparison. MATERIAL AND METHODS: Commercial dental implants were inserted into bovine rib segments of different anatomical origins and densities. Repeated measurements were performed, varying (a) the torque-in force of the devices' attachment screw (the Osstell transducer and the ball attachment, insert for the Periotest device), (b) the insertion site bone quality, and (c) the thread exposure in simulated peri-implant bone defects. RESULTS: Both methods were comparably reliable and showed a strong association to each other in the classification of implant stability. As opposed to torque-forced screw attachment, the variations in bone composition, differences in inter-implant stability of adjacent implants, and peri-implant bone reduction were statistically significant for both methods. CONCLUSIONS: Both non-invasive diagnostic devices seem to be useful in the long-term follow-up of implant integration.

Resonance frequency analysis and damping capacity assessment. Part 2: peri-implant bone loss follow-up. An in vitro study with the Periotest and Osstell instruments
LACHMANN S, LAVAL JY, JAGER B, AXMANN D, GOMEZ-ROMAN G, GROTEN M, WEBER H.,    Department of Prosthodontics, University of Tubingen, Tubingen, Germany.
Evaluation Study, Historical Article
OBJECTIVE: We compared the performance of damping capacity assessment (Periotest device) to resonance frequency analysis (Osstell device) in the assessment of peri-implant bone loss in an in vitro experiment. MATERIAL AND METHODS: Screw-type oral implants were polymerized into acrylic blocks. Peri-implant bone loss was simulated by successively removing defined portions of material surrounding the implants in millimeter increments. Measurement values of both devices were compared by assessing the associated measurement errors, by calculating correlation analyses and drawing scatterplots, and by means of regression analysis referring to increasing bone loss. RESULTS: Both devices produced comparable results suggesting agreement of the measured implant stability values to the actual loss of peri-implant resin. There was a noticeable correlation of the Periotest and Osstell implant stability values. CONCLUSION: The results of this experiment suggest agreement in predicting the actual implant stability with both the instruments with the Osstell instrument being the more precise device.

Implant-borne prosthetic rehabilitation of bone-grafted cleft versus traumatic anterior maxillary defects
LANDES CA., Maxillofacial and Plastic Facial Surgery Department, The J.-W. Goethe University Medical Centre, Frankfurt, Germany.
J Oral Maxillofac Surg. 2006 Feb;64(2):297-307.
PURPOSE: This study hypothesizes comparable implant success in bone-grafted cleft-alveolus versus traumatic anterior maxillary defects. Though of different pathogenesis, both defects comprise bone deficit, scarred periosteum, and soft tissues. Additional complicating factors are isolated. PATIENTS AND METHODS: Twenty cleft and 20 traumatic defect cases were followed-up 48 months in average. After 9 secondary and 11 tertiary cleft-osteoplasties, 25 implants were inserted; in traumatic defects following 8 two-stage and 12 one-stage osteoplasties, 37 incisor or canine implants were inserted. After secondary and tertiary cleft-osteoplasties, 57 and 13 months elapsed until implantation, 4 months in the two-stage posttraumatic osteoplasties. Implants were loaded at 6 months by single crowns. RESULTS: Four (20%) cleft patients faced 2 failures and 2 first-year losses; 2 (10%) trauma cases faced 2 failures and 2 first-year losses; and cumulative 5-year implant success was 80% and 88%, respectively. Other parameters' 12-month results were: values for mean cleft, trauma patients (+ standard deviation), significance of comparison in t testing at a cut-off level of alpha = 0.05; bone loss 0.3+0.5 mm, 0.5+0.7 mm, P < .2; Periotest score 1.1+3.1, 1.2+2.5, P < .7; gingival recession 2.1+0.3 mm, 2.2+0.5 mm, P < .6; periimplant probing depth 2.5+0.5 mm, 2.8+2.6 mm, P < .3. CONCLUSION: Similar success rates without statistically significant differences were found; a multiple factor analysis discerned as positive predictive factors the following; generous transplant volume, 3 to 6 months latency, sufficient implant dimension, early adulthood. Early loading cannot be encouraged from the success rates. Negative predictive factors were spongiosa or milled-bone transplants, dehiscence, smoking, and anorexia. Intraorally harvested membranous bone transplants may prospectively amend secondary osteoplasty-associated bone resorption. Donor site morbidity, local growth, and tooth breakthrough require additional observation in a prospective study when implant insertion should directly follow the growth spurt.

Outcomes of fixed prostheses supported by immediately loaded endosseous implants.
TORTAMANO P, ORII TC, YAMANOCHI J, NAKAMAE AE, GUARNIERI TDE C., Faculdade de Odontologia da Universidade de Sao Paulo, Brazil.
Int J Oral Maxillofac Implants. 2006 Jan-Feb;21(1):63-70.
Evaluation Study
PURPOSE: The aim of this article was to evaluate the survival and success of Straumann implants after immediate loading. A new method for fabricating effective definitive prostheses to immediately load implants in edentulous patients was presented. MATERIALS AND METHODS: Nine patients received 4 implants each, and resin-metal prostheses were installed less than 48 hours after implant placement. Mobility was evaluated immediately after the surgical procedures and 3 months subsequently using the Periotest. Clinical evaluation of soft peri-implant tissues was conducted monthly after the sutures were removed, and radiographs were obtained 6, 12, and 24 months after the surgery. RESULTS: The Periotest revealed statistical values that were stable, with no mobility. No signs of inflammation and/or bleeding were observed. The radiographs did not reveal any continuous areas of radiolucency beyond the first thread of the 36 implants after 24 months. None of them failed, and the success rate was 100%. DISCUSSION: It is possible to submit implants to immediate load without jeopardizing osseointegration if parameters are met, such as suitable bone quality and quantity, lack of unfavorable systemic and psychologic factors, lack of parafunctional habits, strict maintenance of prosthetic requirements, minimization of micromotion, and use of an appropriate surgical protocol. CONCLUSION: Under immediate load, osseointegration of implants is possible, and the method presented for the fabrication of resin-metal prostheses has been reliable and predictable.

Implant-supported mandibular overdentures retained with ball or telescopic crown attachments: a 3-year prospective study
KRENNMAIR G, WEINLANDER M, KRAINHOFNER M, PIEHSLINGER E., Department of Prosthodontics, Dental School, University of Vienna, Austria.
Int J Prosthodont. 2006 Mar-Apr;19(2):164-70.
Randomized Controlled Trial
PURPOSE: The aim of the present study was to evaluate implant survival, peri-implant conditions, and prosthodontic maintenance requirements for implant-supported mandibular overdentures in atrophic mandibles retained with ball or resilient telescopic crown attachments during a 3-year period. MATERIALS AND METHODS: Twenty-five patients with edentulous mandibles each received 2 Camlog root-form dental implants in the mandibular interforaminal (canine) region. The denture attachment system was chosen randomly; 13 patients received ball attachments and 12 patients received resilient telescopic crowns. Implant survival, implant mobility (Periotest values), and peri-implant conditions such as bone resorption, pocket depth, Plaque Index, Gingiva Index, Bleeding Index, and Calculus Index values were assessed for each implant. In addition, detailed prosthodontic maintenance was evaluated during the follow-up period and the 2 retention modalities were compared. RESULTS: There were no differences in implant survival, implant mobility (Periotest values), and peri-implant conditions between the 2 retention modalities. During the 3-year period significantly more complications/interventions for maintenance purposes were registered in the ball group (62 interventions) than in the telescopic crown group (26 interventions; P < .01). CONCLUSION: The results indicate that both ball attachments and resilient telescopic crowns used on isolated implants in the edentulous mandible are viable treatment options. Implant success and peri-implant conditions did not differ between ball attachments and telescopic crowns used as retention modalities for implant overdentures, but the frequency of technical complications was significantly higher with ball attachments than with resilient telescopic crowns.

Occlusal interference during mastication can cause pathological tooth mobility.
ISHIGAKI S, KUROZUMI T, MORISHIGE E, YATANI H., Department of Fixed Prosthodontics, Osaka University Graduate School of Dentistry, Osaka, Japan.
J Periodontal Res. 2006 Jun;41(3):189-92.
BACKGROUND AND OBJECTIVE: Despite little evidence regarding the relationship between tooth mobility and nonworking contact, the evaluation of occlusion is performed mainly by the detection of premature and/or nonworking contacts during tapping movements and lateral excursion. The hypothesis of this study is that occlusal contact during mastication is potentially traumatic to periodontal tissue. It clarifies the relationship between chewing patterns and the status of periodontal tissue. MATERIAL AND METHODS: Subjects included 73 adults, 20-29 years of age (39 men and 34 women), with complete sets of teeth and no history of orthodontic treatment or periodontal disease. The closing chewing patterns of each subject were classified into three groups by the Masticatory Deviation Index, which depicts the deviation from the normal chewing patterns within 5 mm from the intercuspal position. Periotest was used to diagnose teeth mobility and the values were compared among the three groups. RESULTS: The present study indicates that the chewing movements which deviated from the normal chewing movements increased the mobility of specific types of teeth. CONCLUSION: The results of this study imply a relationship between chewing movements and tooth mobility and indicate that functional evaluation of occlusion is necessary for the examination of periodontal tissue. Occlusal evaluation with border and tapping movements might be insufficient, and functional occlusal evaluation during chewing movements can be clinically useful for using to evaluate periodontal tissue.

Comparison of early telescope loading of non-submerged ITI implants in irradiated and non-irradiated oral cancer patients.
LANDES CA, KOVACS AF., Maxillofacial and Plastic Facial Surgery, The J.-W. Goethe, University Medical Centre, Frankfurt, Germany.
Clin Oral Implants Res. 2006 Aug;17(4):367-74.
OBJECTIVE: To compare early dental implant loading in irradiated and non-irradiated oral cancer patients in order to accelerate masticatory function improvement and quality of life. PATIENTS AND METHODS: One hundred and fourteen non-submerged interforaminal ITI implants were early loaded in 30 patients after 3 weeks in situ (telescoped overdenture). Nineteen patients received 72 implants (63%) after local irradiation; 11 non-irradiated patients received 42 implants (37%) with a 24-month follow-up. RESULTS: At 24 month follow-up, one early failure had occurred in an irradiated patient (=99% functioning implants in situ). Peri-implant bleeding and plaque index were similarly high in both groups (40 to 68% average).The Results of other measured parameters were as follows (values for mean; irradiated; non-irradiated patients with respective standard deviations; significance of comparison): bone loss (0.9+/-0.9; 1.4+/-0.9; 0.4+/-0.5 mM; P<0.01); Periotest score (-2.7+/-2.7; -2.4+/-2.2; -3.1+/-3.3; P<0.2); gingival recession (0.6+/-0.7 mM; 0.8+/-0.9 mM; 0.4+/-0.5 mM, P<0.02); and peri-implant probing depths (3+/-1.2; 2.6+/-0.6; 3.4+/-1.7 mM; P<0.002). CONCLUSION: The results suggest reliable non-submerged implantation and early loading. However, bone loss in irradiated mandibles, combined with higher average Periotest values and gingival recession in an oral environment of altered saliva quantity, quality, microflora and local scarring, requires extended follow-up.

Early implant failure. Prognostic capacity of Periotest: retrospective study of a large sample
NOGUEROL B, MUNOZ R, MESA F, DIOS LUNA J, de, O'VALLE F., Department of Periodontology, School of Dentistry, University of Granada, Spain.
Clin Oral Implants Res. 2006 Aug;17(4):459-64.
OBJECTIVES: The objectives of this study were to determine the accuracy of Periotest to monitor primary implant stability at first-stage surgery, to identify by multivariate analysis the variables associated with early implant failure and to compare Periotest with radiographic study in the diagnosis of implant stability at second-stage surgery (during osseointegration period). MATERIAL AND METHODS: A 10-year retrospective study was conducted on 1084 Branemark implants placed in 316 patients. Clinical variables, implant diameter and length, Periotest values (PTVs) and radiological variables were analyzed in bivariate and multivariate studies in order to determine their influence on early implant failure. RESULTS: After examination of the sensitivity and specificity values obtained for different PTV cutoff points, a cutoff PTV of -2 was selected (84% sensitivity and 39% specificity). In the bivariate analysis, early failure was significantly related to smoking habits, implant location, bone type, implant features and PTVs (-2 and >or=-2). In the final multiple logistic model, only age (odds ratio (OR)=4.53; 95% confidence interval (CI), 1.34-15.27), smoking habits (OR=2.5; 95% CI, 1.3-4.79), bone type (OR=1.93; 95% CI, 1.01-3.7) and PTV at first surgery (OR=3.01; 95% CI, 1.5-6.02) were independently related to early failure. CONCLUSIONS: The Periotest (with -2 cutoff) at first surgery offers high sensitivity in the prognosis of early implant loss and shows a greater capacity to evaluate stability during the osseointegration period compared with radiographic study.

A prospective clinical study on titanium implants in the zygomatic arch for prosthetic rehabilitation of the atrophic edentulous maxilla with a follow-up of 6 months to 5 years.
APARICIO C, OUAZZANI W, GARCIA R, AREVALO X, MUELA R, FORTES V.,     Department of Biomaterials, Institute for Surgical Sciences, Sahlgrenska Academy, Goteberg University, Goteberg, Sweden.
Clin Implant Dent Relat Res. 2006;8(3):114-22.
BACKGROUND: Prosthetic rehabilitation with implant-supported prostheses in the atrophic edentulous maxilla often requires a bone augmentation procedure to enable implant placement and integration. However, a rigid anchorage can also be achieved by using so-called zygomatic implants placed in the zygomatic arch in combination with regular implants placed in residual bone. PURPOSE: The aim of the present study was to report on the clinical outcome of using zygomatic and regular implants for prosthetic rehabilitation of the severely atrophic edentulous maxilla. MATERIALS AND METHODS: Sixty-nine consecutive patients with severe maxillary atrophy were, during a 5-year period, treated with a total of 69 fixed full-arch prostheses anchored on 435 implants. Of these, 131 were zygomatic implants and 304 were regular implants. Fifty-seven bridges were screw-retained and 12 were cemented. The screw-retained bridges were removed at the examination appointments and each implant was tested for mobility. In addition, the zygomatic implants were subjected to Periotest (Siemens AG (now Medizintechnik Gulden), Bensheim, Germany) measurements. The patients had at the time of this report been followed for at least 6 months up to 5 years in loading. RESULTS: Two regular implants failed during the study period giving a cumulative survival rate of 99.0%. None of the zygomatic implants was removed. All patients received and maintained a fixed full-arch bridge during the study. Periotest measurements of zygomatic implants showed a decreased Periotest values value with time, indicating an increased stability. Three patients presented with sinusitis 14-27 months postoperatively, which could be resolved with antibiotics. Loosening of the zygomatic implant gold screws was recorded in nine patients. Fracture of one gold screw as well as the prosthesis occurred twice in one patient. Fracture of anterior prosthetic teeth was experienced in four patients. CONCLUSIONS: The results from the present study show that the use of zygomatic and regular implants represents a predictable alternative to bone grafting in the rehabilitation of the atrophic edentulous maxilla.

Primary stability of a conical implant and a hybrid, cylindric screw-type implant in vitro.
SAKOH J, WAHLMANN U, STENDER E, NAT R, AL-NAWAS B, WAGNER W., Department of Oral and Maxillofacial Surgery, University Hospital Mainz, Mainz, Germany.
Int J Oral Maxillofac Implants. 2006 Jul-Aug;21(4):560-6.
PURPOSE: The differences with respect to primary stability between 2 Camlog implants, a conical implant, and a hybrid cylindric screw-type implant, were investigated in vitro. The effect of underdimensioned implant bed preparation was also studied for both implant designs. MATERIALS AND METHODS: In an in vitro model the stability of different implants in fresh porcine iliac bone blocks was measured using torque moment values, the Periotest, resonance frequency analysis, and push-out testing. Results: The conical implant showed significantly higher primary stability than the cylindric hybrid implant using the insertion torque, Periotest, and push-out tests. For both types of implants, the torque moment values following under-dimensioned preparation were significantly better than those obtained following the standard drilling protocol (Conical: 25.00 vs 11.00 Ncm; Cylindrical: 11.75 vs. 5.75 Ncm). For the cylindric implant, significantly better results following under-dimensioned implant bed preparation were observed only with the insertion torque and the pushout testing values. The mean ISQ values for all groups were between 55 and 57; no statistical differences with respect to ISQ could be found. CONCLUSION: In this in vitro model conical implants showed higher primary stability than cylindric implants. The procedure of under-dimensioned drilling seemed to increase primary stability for both types of implants; however, the effect was only observable using insertion torque. RFA and Periotest, the noninvasive, clinical methods tested, did not clearly demonstrate this difference.

Validity and clinical significance of biomechanical testing of implant/bone interface.
APARICIO C, LANG NP, RANGERT B., Private Practice, Clinica Aparicio, Barcelona, Spain and Department of Biomaterials, Institute for Clinical Sciences, Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden.
Clin Oral Implants Res. 2006 Oct;17 Suppl 2:2-7.
Purpose: The aim of this paper was to review the clinical literature on the Resonance frequency analysis (RFA) and Periotest techniques in order to assess the validity and prognostic value of each technique to detect implants at risk for failure. Material and methods: A search was made using the PubMed database to find clinical studies using the RFA and/or Periotest techniques. Results: A limited number of clinical reports were found. No randomized-controlled clinical trials or prospective cohort studies could be found for validity testing of the techniques. Consequently, only a narrative review was prepared to cover general aspects of the techniques, factors influencing measurements and the clinical relevance of the techniques. Conclusions: Factors such as bone density, upper or lower jaw, abutment length and supracrestal implant length seem to influence both RFA and Periotest measurements. Data suggest that high RFA and low Periotest values indicate successfully integrated implants and that low/decreasing RFA and high/increasing Periotest values may be signs of ongoing disintegration and/or marginal bone loss. However, single readings using any of the techniques are of limited clinical value. The prognostic value of the RFA and Periotest techniques in predicting loss of implant stability has yet to be established in prospective clinical studies.

References: ... 1989    1990    1991    1992  1993    1994    1995    1996    1997    1998    1999    2000    2001    2002
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Clinical efficacy of semiconductor laser application as an adjunct to conventional scaling and root planing
KREISLER M, AL HAJ H, D'HOEDT B., Department of Oral Surgery, Johannes Gutenberg-University Mainz, Mainz, Germany.
Lasers Surg Med. 2005 Dec;37(5):350-5.
BACKGROUND AND OBJECTIVES: The aim of the in vitro study was to examine the clinical efficacy of semiconductor laser periodontal pocket irradiation as an adjunct to conventional scaling and root planing. MATERIALS AND METHODS: Twenty-two healthy patients with a need of periodontal treatment (15 women, 7 men, mean age 45.0 +10.8 years) with at least four teeth in all quadrants, were included. All of them underwent a conventional periodontal treatment including scaling and root planing. Using a split mouth design, two randomly chosen quadrants (one upper and the corresponding lower one) were subsequently treated with an 809 nm GaAlAs laser operated at a power output of 1.0 Watt using a 0.6 mm optical fiber. The teeth in the control quadrants were rinsed with saline. The clinical outcome was evaluated by means of plaque index (PI), gingival index (GI), bleeding on probing (BOP), sulcus fluid flow rate (SFFR), Periotest (PT), probing pocket depth (PPD), and clinical attachment loss (CAL) at baseline and at 3 months after treatment. A total of 492 teeth in both groups were evaluated and differences between the laser and the control teeth were analyzed using the Wilcoxon test (P < 0.05). RESULTS: Teeth treated with the laser revealed a significantly higher reduction in tooth mobility, pocket depth, and clinical attachment loss. Twelve percent of the teeth in the laser group showed an attachment gain of 3 mm or more, compared to 7% in the control group. An attachment gain of 2-3 mm was found in 24% of the teeth in the laser group and 18% in the control group. No significant group differences, however, could be detected for the plaque index, gingival index, bleeding on probing, and the sulcus fluid flow rate. CONCLUSIONS: The higher reduction in tooth mobility and probing depths is probably not predominantly related to bacterial reduction in the periodontal pockets but to the de-epithelization of the periodontal pockets leading to an enhanced connective tissue attachment. The application of the diode laser in the treatment of inflammatory periodontitis at the irradiation parameters described above is a safe clinical procedure and can be recommended as an adjunct to conventional scaling and root planing. (c) 2005 Wiley-Liss, Inc.

Periotest-analysis in penradicular surgery: preliminary results of a clinical-prospective study
CANTELMI G, FREI C, ARX T. VON, Klinik fur Oralchirurgie und Stomatologie, Zahnmedizinische Kliniken der Universitat Bern.
Schweiz Monatsschr Zahnmed. 2005;115(10):903-8.
The two objectives of the present study were: to assess the healing after periradicular surgery using the Periotest device, and to compare the recorded Periotest values with the healing category determined after a one-year follow-up using radiographic and clinical criteria. In 43 patients with periradicular surgery, Periotest values could be recorded pre- and postoperatively, as well as after six and twelve months. Cases with a successful healing, as determined at the one-year follow-up, demonstrated a continuous decrease of the Periotest values over time, whereas one-year failures showed increasing Periotest values over the study period. In control teeth, the Periotest values remained unchanged for the whole study period. It appears that the Periotest measurements correlate with the postoperative healing mode following periradicular surgery, and therefore, allow an additional assessment of the healing outcome.

Predisposing conditions for retrograde peri-implantitis, and treatment suggestions.
QUIRYNEN M, VOGELS R, ALSAADI G, NAERT I, JACOBS R, VAN STEENBERGHE D., Department of Periodontology, Faculty of Medicine, School of Dentistry, Oral Pathology & Maxillo-Facial Surgery, Katholieke Universiteit Leuven, Leuven, Belgium.
Clin Oral Implants Res. 2005 Oct;16(5):599-608.
BACKGROUND: Recent case reports introduced the term retrograde peri-implantitis as a lesion (radiolucency) around the most apical part of an osseointegrated implant. It develops within the first months after insertion. This retrospective study aimed to find predisposing conditions for such peri-apical lesions and to evaluate treatment strategies. METHODS: All single implants (426 in the upper, 113 in the lower jaw, all Branemark system type) placed at the department of Periodontology of the University Hospital (Catholic University Leuven) were included in this retrospective evaluation to check the incidence of retrograde peri-implantitis. Eventual predisposing factors such as patient characteristics (age, medical history), recipient site (local bone quality and quantity, cause of tooth loss), periodontal and endodontic conditions of neighboring teeth, implant characteristics (length, surface characteristics), and surgical aspects (guided bone regeneration, osseous fenestration, or dehiscency) were considered. Moreover, implants with retrograde peri-implantitis were followed longitudinally to verify their treatment outcome by means of different parameters (Periotest values (PTV), marginal bone level, radiological size of peri-apical defect). RESULTS: Seven implants in the upper (1.6%) and 3 in the lower jaw (2.7%) showed retrograde peri-implantitis, before or at abutment connection. In comparison with successful implants, such peri-apical lesions occurred preferably at sites with a history of an obvious endodontic pathology of the extracted tooth to be replaced. The incidence of retrograde peri-implantitis was significantly higher (P<0.0001) for TiUnite implants when compared with the machined implants (8/80 vs. 2/459). The machined implant surface, however, showed a higher failure rate (6.8%) than the TiUnite implants (2.5%). Failures with machined surfaces preferably occurred at extraction sites of teeth with a history of endodontic pathology or sites adjacent to teeth with an obvious endodontic pathology. No other predisposing factors could be identified. A curettage of the peri-apical lesions and the use of a bone substitute material prevented further progression of such lesions in the upper jaw (implants maintained their marginal bone and low PTV scores). A treatment in the lower jaw was less successful. CONCLUSIONS: Within the limitations of a retrospective study, these results seem to indicate that retrograde peri-implantitis is provoked by remaining scar or granulomatous tissue at the recipient site: endodontic pathology of extracted tooth (scar tissue-impacted tooth) or possible endodontic pathology from a neighboring tooth.

Evaluation of dental injury following endotracheal intubation using the Periotest technique.
HOFFMANN J, WESTENDORFF C, REINERT S., Department of Oral and Maxillofacial Plastic Surgery, Tubingen University Hospital, Osianderstr, Germany.
Dent Traumatol. 2005 Oct;21(5):263-8
The hazards of damage to teeth and their periodontal attachment during tracheal intubation are well known. Dental trauma represents the commonest single reason for complaints against anesthesiologists. In order to predict the possible risk of perianesthetic iatrogenic tooth luxation we evaluated the use of a measuring method (Periotest technique), being well established for the diagnosis of periodontal disease. In 120 patients undergoing elective surgery, we compared the amount of tooth mobility before and after general anesthesia to different scores assessing the difficulty of tracheal intubation. Furthermore, the level of work experience of the intubating anesthetist was compared with the degree of postoperative tooth mobility. Changes of periodontal attachment could not be detected by the Periotest technique. The Periotest technique does not seem to have the ability to detect early periodontal changes associated with endotracheal intubation.

Histomorphometric and mechanical analyses of the drill-free screw as orthodontic anchorage.
KIM JW, AHN SJ, CHANG YI. , Dental Research Institute, Department of Orthodontics, Seoul National University, Korea.
Am J Orthod Dentofacial Orthop. 2005 Aug;128(2):190-4.
INTRODUCTION: Drill-free screws were developed to provide convenient orthodontic anchorage. The purpose of this study was to evaluate the effects of the drilling procedure on the stability of the screws under early orthodontic loading. METHODS: Thirty-two screws were inserted into the jaws of 2 beagles. The screws were divided into 2 groups of 16: the drilling group and the drill-free group. Screws in the drilling group were inserted into the site that had been drilled with a pilot drilling bur, and those in the drill-free group were inserted without drilling. A force of 200 to 300 g was applied using nickel-titanium coil springs 1 week after insertion. Twelve weeks after insertion, mobility was tested with Periotest (Siemens AG (now Medizintechnik Gulden), Bensheim, Germany), and the screws with the surrounding bone were prepared for histomorphometric evaluation. RESULTS: Screws in the drill-free group showed less mobility and more bone-to-metal contact; they had more bone area compared with the drilling group, although bone osseointegration was generally found in both groups. CONCLUSIONS: With careful technique, drill-free screws can provide stable orthodontic anchorage.

Diagnosis of ankylosis in permanent incisors by expert ratings, Periotest and digital sound wave analysis.
CAMPBELL KM, CASAS MJ, KENNY DJ, CHAU T., Department of Dentistry, Bloorview MacMillan Children's Centre, University of Toronto, Toronto, Canada.
Dent Traumatol. 2005 Aug;21(4):206-12.
The objectives of this investigation were to: (i) assess the reliability of expert raters to detect ankylosis from recordings of percussion sounds, (ii) measure differences in Periotest values (PTV) between ankylosed and non-ankylosed incisors and (iii) identify characteristic differences in recorded percussion sounds from ankylosed and non-ankylosed incisors using digital sound wave analysis. A convenience sample of healthy children (age range 7-18 years) was invited to participate. Ankylosis group children had one or more documented ankylosed maxillary incisors. Control group children had intact, non-ankylosed incisors. Digital recordings of percussion sounds and PTV were acquired for each incisor of interest. Four experienced pediatric dentists rated the randomized percussion sound pairs for the presence of ankylosis. Percussion sounds were also subjected to digital sound wave analysis. Overall agreement for the expert raters was substantial (kappa = 0.7). Intra-rater agreement was substantial to almost perfect (kappa = 0.6-0.9). Diagnosis of ankylosis demonstrated sensitivity of 76-92% and specificity of 74-100%. PTV from ankylosed incisors were statistically lower than PTV from non-ankylosed incisors. Ankylosed incisor digital sound wave signals exhibited significantly more energy in high-frequency bands than non-ankylosed incisors. This investigation demonstrated that: (i) experienced pediatric dentists reliably detected ankylosis by percussion sound alone; (ii) PTV for ankylosed incisors were statistically lower than PTV from non-ankylosed incisors; and (iii) ankylosed incisors exhibited a higher proportion of their signal energy in high-frequency bands.

Zygoma implant-supported midfacial prosthetic rehabilitation: a 4-year follow-up study including assessment of quality of life.
LANDES CA., Maxillofacial and Plastic Facial Surgery, The J.-W. Goethe University Medical Centre Frankfurt, Theodor-Stern-Kai 7, 60596 Frankfurt am Main, Germany.
Clin Oral Implants Res. 2005 Jun;16(3):313-25.
OBJECTIVE: Successful prosthetic rehabilitation is crucial for quality of life in cases of large maxillary defects when surgical reconstruction is not advisable because of general health or patient refusal. For this purpose, the extended indications for Zygomaticus fixtures in different defect types were evaluated. PATIENTS AND METHODS: Twelve patients received 28 zygoma implants and 23 dental implants (if a segment of alveolar process was available) and were followed-up 14-53 months. Zygoma implants were positioned classically in the maxillary molar region and to reduce leverage, a premolar and a canine position was developed. The quality of life was assessed by a validated questionnaire after complete rehabilitation. RESULTS: Cumulative zygoma implant survival was 82%. Three losses occurred because of persistent infection and gradual loosening. Lost implants were immediately replaced in adjacent bone. Insufficient implant length within soft tissue reconstructions was prone to chronic infection by pocketing and recurrent overgrowth of granulating tissue. Longer implants were free of soft tissue inhibition, yet prone to overloading and high leverage in cases when no anterior alveolar process and dental implants were present. Zygoma implant success was therefore 71%, including the new premolar and canine Zygomaticus fixture-position. Periotest values increased from 0 to +7 to the fourth year, peri-implant bleeding and plaque index were decreasing from 56% to 0% and 33% to 0%, respectively, and good general quality of life with the priorities on chewing and activity was noted. CONCLUSION: Zygoma implants can reliably anchor the midfacial maxillary prostheses and enable a quality of life comparable with autologous maxillary reconstruction. They can be replaced immediately if local infection or loosening should occur. A premolar and canine position reduce leverage when no anterior alveolar process is present. The patient can alternatively be provided with dental implants.

Immediate occlusal loading of freestanding implants using cortical satellite implants: preliminary report of a prospective study.
ENGELKE W, DECCO OA, DE LAS MERCEDES CAPOBIANCO M, SCHWARZWALLER W, VILLAVICENCIO MM., Department of Oral Surgery, Georg August Universitat Gottingen, Robert Koch Strasse 40, D-37075 Gottingen, Germany.
Implant Dent. 2005 Mar;14(1):50-7.
Freestanding implants with mandibular overdentures are used frequently after 3 months' healing time. Immediate full loading may be applied to this approach if sufficient primary stability is provided. The present study evaluates the success rate of two single-standing interforaminal implants stabilized with cortical satellite implants and loaded immediately with overdentures. Twenty patients (five male and 15 female; age, 45-87 years) received two single-standing titanium screw implants (Semados, Bego, Bremen, Germany). All implants were stabilized during healing time with cortical satellite implants (2.0-mm bone screws; Medartis, Basel, Switzerland) via individual connectors attached to the implant abutment subgingivally. Mandibular overdentures were incorporated immediately after surgery using ball attachments as retentive elements. The patients were under no restrictions concerning diet and loading. The satellite implants were removed after 3 months. All implants were osseointegrated after 10 months' mean observation time. The mean Periotest value was -4.9, and the mean marginal bone loss was 0.7 mm. No dropouts were observed, and 19 of 20 patients would recommend the treatment to a close friend. Preliminary follow-up data indicate that cortical stabilization of two anterior mandibular implants with satellite implants leads to osseointegration of the implants under immediate load conditions with an overdenture. This concept contributes to reduction of prosthetic treatment costs and permits immediate enhancement of masticatory function.

Longitudinal measurements of tooth mobility during orthodontic treatment using a periotest.
TANAKA E, UEKI K, KIKUZAKI M, YAMADA E, TAKEUCHI M, DALLA-BONA D, TANNE K., Department of Orthodontics and Craniofacial Developmental Biology, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima, Japan.
Angle Orthod. 2005 Jan;75(1):101-5.
The present study was designed to investigate the alteration of tooth mobility through orthodontic treatment using a Periotest. Eighty-three crowding cases without severe skeletal discrepancies were used as subjects. For each subject, the mobility of the central and lateral incisors on both arches (U1, U2, L1, and L2) was measured immediately before and after orthodontic treatment (T1 and T2 stages) and after retention (T3 stage) by use of a Periotest. No significant differences of all the measurements were found between the left and right sides. At T1 stage, the mean values were 10.8, 10.4, 9.3, and 7.4 for U1, U2, L1, and L2, respectively. At T2 stage, the Periotest values for all the teeth increased in comparison with those at T1 stage, and significantly decreased at T3 stage compared with those at T2 stage. Negative correlations were found between the Periotest value and age, which imply that tooth mobility decreases with age. The durations of treatment and retention had low correlation with the change of tooth mobility for all the teeth. It is suggested that the tooth mobility before treatment and after retention may be one of the useful indicators for determination of the retention period.

Immediate loading of single-tooth implants in the posterior region.
ABBOUD M, KOECK B, STARK H, WAHL G, PAILLON R., Department of Oral Surgery, Rheinische Friedrich-Wilhelms University, Welschnonnen- str. 17, 53111 Bonn, Germany.
Int J Oral Maxillofac Implants. 2005 Jan-Feb;20(1):61-8.
PURPOSE: The aim of this study was to evaluate the clinical response and safety of immediately loaded single-tooth implants placed in the posterior region of the maxilla and mandible. MATERIALS AND METHODS: Single-tooth implants were placed in healed extraction sites in 20 adult patients. Temporary pre-fabricated acrylic resin crowns were prepared and adjusted. The crown occlusion was adjusted to obtain minimal contacts in maximum intercuspation. After 6 weeks a ceramometal or all-ceramic crown was cemented. Radiographic and clinical examinations were made at baseline and at 3, 6, and 12 months. Cortical bone response and peri-implant mucosal responses were evaluated. RESULTS: The marginal bone level at the time of implant placement was preserved. The mean change in marginal bone level was 0.01 mm at 12 months. The mean Periotest value after 360 days was -4. The peri-implant mucosal adaptation to the anatomic form of the provisional crown resulted in a natural esthetic outcome, and a gain in papilla length was observed. One implant failure was recorded because of provisional luting cement impaction. DISCUSSION: Clinical research has shown that immediate loading is a possible treatment modality. The immediate functional loading of implants placed in this study resulted in bone adaptation to loading. A satisfactory success rate with positive tissue responses was achieved. CONCLUSIONS: The results of this limited investigation indicated that immediate loading of unsplinted single-tooth implants in the posterior region may be a viable treatment option with an esthetic outcome.

References:  ... 1989    1990    1991    1992  1993    1994    1995    1996    1997    1998    1999    2000    2001    2002
                       2003    2004    2005      2006      ...........

Tooth mobility after periodontal surgery.
FELLER L, LEMMER J., Department of Periodontology and Oral Medicine, Faculty of Dentistry, Medical University of Southern Africa.
SADJ. 2004 Nov;59(10):407, 409-11.
Changes in tooth mobility after surgical crown lengthening procedures were examined with a modern electro-mechanical instrument (Periotest) in a total of 37 teeth in 14 patients between the ages of 18 and 55 years. Seven teeth were incisors, three canines, thirteen pre-molars and fourteen were molars. Periotest values, probing depths, bleeding indices and plaque indices were recorded after the initial preparation stage of the periodontal treatment, and further Periotest values and plaque and bleeding indices were recorded at intervals up to 3 months after surgery. In each category of teeth there was a progressive increase in tooth mobility starting immediately after surgery and peaking about the seventh day. The mobility then declined steadily to approach the base line again at about 3 months. There were statistically significant differences in mobility after surgery between tooth types (p < 0.01). Gender and age did not significantly affect the values. The pattern of post-surgical tooth mobility can be closely correlated with the known biological events of post-surgical healing.

Effect of recombinant human bone morphogenetic protein-2 on the osseointegrationof dental implants: a biomechanics study.
SYKARAS N, IACOPINO AM, TRIPLETT RG, MARKER VA., Department of Fixed Prosthodontics, Dental School, Athens University, Athens,Greece.
Clin Oral Investig. 2004 Dec;8(4):196-205
BACKGROUND. Bone augmentation procedures in combination with dental implantsenhance osseointegration in areas that demonstrate localized bone deficit.Clinical confirmation of a biomechanically stable interface is essential forfunctional implant loading. PURPOSE. The aim of this study was to evaluatebiomechanically the effect of recombinant human bone morphogenetic protein(rhBMP)-2 on implant osseointegration and correlate it with Periotest andradiographic measurements. MATERIALS AND METHODS. Hollow cylinder implants werefilled with absorbable collagen sponge soaked with rhBMP-2 or left empty andimplanted in dog mandibles. The animals were followed for 4, 8, and 12 weeks,Periotest assessment was performed at the end of each time interval, andspecimens were collected for pullout biomechanical testing and radiographicevaluation of bone-implant contact levels. RESULTS. Periotest assessment did notprovide evidence of statistically significant differences between the two groupsand correlated well with the radiographic bone-implant contact levels. Thepullout test revealed a higher correlation between force/displacement anddisplacement/energy for the experimental group, suggesting that the addition of rhBMP-2 did influence the rate of osseointegration. CONCLUSION. The results fromthe pullout test support the potential role of rhBMP-2 in clinical applicationsby promoting a biomechanically mature interface at 12 weeks. However,radiographic and Periotest assessment of the bone-implant interface did notprovide evidence of the differences observed with biomechanical testing.

Clinical analysis of wide-diameter frialit-2 implants.
KRENNMAIR G, WALDENBERGER O., Dental School, University of Vienna, Vienna, Austria.
Int J Oral Maxillofac Implants. 2004 Sep-Oct;19(5):710-5.
PURPOSE: To evaluate wide-diameter (ie, 5.5-mm-wide) Frialit-2 implants used for several forms of prosthetic rehabilitation. MATERIALS AND METHODS: In this retrospective study, 121 wide implants (74 maxillary, 47 mandibular) were placed in 114 patients (61 female, 53 male, mean age 37.2 +/- 14.9 years). Thirty-six single-tooth restorations, 63 fixed partial dentures (68 implants), 6 removable overdentures (7 implants), and 3 fixed complete dentures (8 implants) were placed. Eighty-seven were placed in the molar regions. The follow-up period for the implants was 12 to 114 months (mean 41.8 +/- 18.5 months). Peri-implant bone loss, pocket depth, Plaque Index values, Bleeding Index values, and Periotest values were evaluated. RESULTS: Overall, 2 maxillary implants were lost, for a cumulative survival rate of 98.3% (97.3% in the maxilla; 100% in the mandible). Mean peri-implant pocket depth (3.4 +/- 1.1 mm), bone resorption (1.4 +/- 1.2 mm), Periotest values (-4.3 +/- 3.1) as well as the Plaque Index and Bleeding Index (grades of 0 in 80% of cases) indicated acceptable results. DISCUSSION: The high survival rate may be attributed to avoidance of the use of short wide-diameter implants, and the primary intention to place wide-diameter implants. Preference of the molar region was a consequence of the peri-implant bone situation in the premolar region, which was frequently inadequate for a 5.5-mm implant. CONCLUSIONS: The use of wide-diameter implants can be a viable treatment option and may provide benefits in posterior regions for long-term maintenance of various implant-supported prosthetic rehabilitations. Some anatomic and prosthodontic limitations for the use of wide implants were

AICRG, Part I: A 6-year multicentered, multidisciplinary clinical study of a newand innovative implant design.
MORRIS HF, OCHI S, CRUM P, ORENSTEIN IH, WINKLER S., Dental Clinical Research Center, Ankylos Implant Clinical Research Group,Department of Veterans Affairs Medical Center, Ann Arbor, MI 48105, USA.
J Oral Implantol.  2004;30(3):125-33.
Clinical Trial    Multicenter Study
PROBLEM: Repetitive microstrains, which occur at the bone-implant interfaceduring function, can lead to implant loss. In an attempt to improve survival bydirecting the stresses during function away from the dense cortical bone andtoward the resilient trabecular bone, the Ankylos implant was developed with aroughened, progressive thread and a smooth cervical collar. The highly polishedcollar reduces the stresses in areas of the crestal bone. A precisely machinedMorse taper prevents rotation of the abutment on the implant and eliminates themicrogap present in many 2-stage implant systems. Clinical studies of otherimplants at different clinical research centers have demonstrated varyingdegrees of survival. PURPOSE: The purpose of this paper was (1) to assess theoverall clinical survival of this new implant design and (2) to compare implantstability (ie, Periotest values [PTVs]) over time with other implants. METHOD:The investigation represented a comprehensive, multicentered, internationalclinical study conducted over a period of 6 years. It was conducted under anInvestigational Device Exemption (IDE) protocol that was reviewed and acceptedin the United States by the Food and Drug Administration (FDA). Over 1500implants were placed and restored, and follow-up data were gathered for a periodof up to 3 to 5 years. RESULTS: Over 44% of the clinical research centersreported no failures (100% survival). A total of 63% of the centers had none oronly 1 failure during the study. One center reported 6 failures in 1 patient,which were not related to the implant design. Overall survival for implants infunction for 3 to 5 years was 97.5%. Using failure criteria of earlier studiesof other implants, 5-year survival was 98.3%. Higher handpiece speeds wereassociated with an increase in the number of failures. This new design produceda slightly more resilient trabecular bone-implant complex with a difference ofabout 1 PTV in all bone densities when compared with other implants.CONCLUSIONS: The following conclusions can be made: (1) the implant design waseffective under all clinical conditions; (2) no significant and unexpectedcomplications or risk factors were evident; (3) survival was found to beexcellent; and (4) this implant is well suited for use in the restoration ofmasticatory function and esthetics in patients with missing natural teeth.

A 10-year randomized clinical trial on the influence of splinted and unsplinted oral implants retaining mandibular overdentures: peri-implant outcome.
NAERT I, ALSAADI G, VAN STEENBERGHE D, QUIRYNEN M., Department of Prosthetic Dentistry/BIOMAT Research Group, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven, Leuven, Belgium.
Int J Oral Maxillofac Implants. 2004 Sep-Oct;19(5):695-702.
PURPOSE: This randomized controlled clinical trial aimed to evaluate the efficacy of splinted implants versus unsplinted implants in overdenture therapy over a 10-year period. MATERIALS AND METHODS: The study sample comprised 36 completely edentulous patients, 17 men and 19 women (mean age 63.7 years). In each patient, 2 implants (Branemark System, Nobel Biocare, Goteborg, Sweden) were placed in the interforaminal area. Three to 5 months after placement, they were connected to standard abutments. The patients were then rehabilitated with ball-retained overdentures, magnet-retained overdentures, or bar-retained overdentures (the control group). Patients were followed for 4, 12, 60, and 120 months post-abutment connection. Group means as well as linear regression models were fitted with attachment type and time as classification variables and corrected for simultaneous testing (Tukey). RESULTS: After 10 years, 9 patients had died and 1 was severely ill. Over 10 years, no implants failed. Mean Plaque Index, Bleeding Index, change in attachment level, Periotest values, and marginal bone level at the end of the follow-up period were not significantly different among the groups. DISCUSSION: The annual marginal bone loss, excluding the first months of remodeling, was comparable with that found around healthy natural teeth. CONCLUSION: The fact that no implants failed and that overall marginal bone loss after the first year of bone remodeling was limited suggested that implants in a 2-implant mandibular overdenture concept have an excellent prognosis in this patient population, irrespective of the attachment system used.

Dynamic fatigue resistance of implant-abutment junction in an internally notchedmorse-taper oral implant: influence of abutment design.
CEHRELI MC, AKCA K, IPLIKCIOGLU H, SAHIN S., Department of Prosthodontics, Faculty of Dentistry, Hacettepe University,Sihhiye, Ankara, Turkey.
Clin Oral Implants Res.  2004 Aug;15(4):459-65.
Abstract Purpose: To compare dynamic fatigue resistance of one- and two-pieceabutments connected to internally notched morse-taper oral implants. Materialand methods: Sixteen synOcta(R) ITI(R) implants were tightened into two metalmodels. SynOcta(R) abutments for cement-retained restorations and solidabutments were divided into two equal groups and were torque-tightened into theimplants. Each implant received a cement-retained crown. Cyclic dynamic axialand lateral peak loads of 75+5 N were applied on the implants for a duty of500,000 cycles at 0.5 Hz, and at an angle of 20 degrees. Prior to theexperiments and at each 100,000 cycles of loading, Periotest values (PTVs) weremeasured. Removal torque values (RTVs) of the abutments were also measured witha custom-made torque device at the termination of the experiment. Results: Allabutments and implants were clinically immobile and without any signs ofmechanical failure. The final PTVs for both abutments were similar and thedifference between groups was insignificant (P>0.05). The RTVs of solidabutments were significantly higher than synOcta(R) abutments (P<0.05).Conclusion: Predictable long-term clinical results can be achieved with solidabutments and synOcta(R) abutments for cement-retained restorations. Solidabutments possess higher removal torque resistance than synOcta(R) abutmentswhen connected to synOcta(R) ITI(R) implants.

Prospective clinical evaluation of dental implants with sand-blasted, large-grit, acid-etched surfaces loaded 6 weeks after surgery.
TORTAMANO NETO P, CAMARGO LO., Department of Prosthodontics, University of Sao Paulo, Sao Paulo, Brazil.
Quintessence Int. 2004 Oct;35(9):717-22.
Twenty implants with sand-blasted, large-grit, acid-etched (SLA) surfaces (ITI Dental System) were followed up for a period of 12 months, during which the following clinical criteria were evaluated: (a) absence of persistent clinical symptoms (pain, strange sensations, or paresthesia) after the placement of implants; (b) absence of recurring peri-implant inflammation or suppuration; (c) absence of increasing mobility, tested with Periotest; and (d) absence of bone loss or radiolucency around the implants. After 12 months of follow-up, all the loaded implants, after 6 weeks of placement, were approved under all the aforementioned criteria. During the analysis of the increasing mobility, tested with Periotest, and grouping these implants according to the site of implantation (mandible or maxilla), it was possible to observe that the implants presented the same increasing mobility.

Six-month performance of implants with oxidized and machined surfaces restoredat 2, 4, and 6 weeks postimplantation in adult beagle dogs.
KNOBLOCH L, LARSEN PA, RASHID B, CARR AB., Ohio State University College of Dentistry, Department of Restorative Dentistry,Prosthodontics, and Endodontics, Columbus, Ohio, USA.
Int J Oral Maxillofac Implants.  2004 May-Jun;19(3):350-6.
PURPOSE: The purpose of this study was to compare machined-surface implants(control) and oxidized-surface titanium screw-type implants (test) loaded withfixed partial dentures at 2, 4, and 6 weeks postplacement in terms of implantsurvival and stability. MATERIALS AND METHODS: The beagle model was chosen forthe study. Four mandibular premolars were extracted bilaterally from each dog.After 2 months of healing, 4 implants were placed in each dog. Half of the dogs(n = 6), the test group, received oxidized-surface implants; the other half (n =6), the control group, received machined-surface implants. In each group, 2 dogswere randomly assigned to a 2-week preloading healing period, 2 to a 4-weekperiod, and 2 to a 6-week period. Three implants were loaded in each dog; 1 wasleft unloaded as a control. Clinical stability and survival were monitored every2 weeks for 6 months. RESULTS: Failures were noted only among the implantsassigned to the 2- and 4-week groups. Failures accounted for 9.4% (9/96) of theimplants--12.5% (6/48) of the control implants and 6.3% (3/48) of the testimplants. One hundred percent prosthesis stability was noted for thetest-surface implant group. Stability of the test implants was significantlybetter than stability of the control implants (-2.6 vs -1.7, P < .05). Mean Periotest values at loading were 3.7 for the group loaded at 2 weeks, 1.6 forthe group loaded at 4 weeks, and 0.6 for the group loaded at 6 weeks. Fiftypercent of the 6-week group, 25% of the 4-week group, and 12.5% of the 2-weekgroup had a Periotest value < 0 at loading. DISCUSSION: The results reveal aqualitative difference in performance between the implant groups. Twice as manyfailures occurred in the control group, few failures occurred following loading,and no failures occurred after 4 weeks postplacement. The survival curves forboth implants were flat after 4 weeks; however, the duration of follow-up mayhide effects of time-dependent factors on survival and poses a concern forclinical inference. CONCLUSIONS: Early loading of both implant types was welltolerated, as only 2 failures occurred following loading. A subsequent reportwill review these outcomes along with histomorphometric data collected at 6months to better understand the significance of tissue-level implant-surfaceinteraction for survival and stability.

Mandibular two-implant telescopic overdentures.
HECKMANN SM, SCHROTT A, GRAEF F, WICHMANN MG, WEBER HP., School of Dental Medicine, University of Erlangen-Nuremberg, Erlangen, Germany.
Clin Oral Implants Res. 2004 Oct;15(5):560-9.
To stabilize mandibular overdentures in edentulous patients, various connector types which can be attached to between two and four implants placed in the anterior mandible are possible. Treatment using non-rigid telescopic connectors on two interforaminal implants for overdenture stabilization began in 1989. The objective of this study is to investigate soft- and hard-tissue conditions as well as prosthesis function after a period of 10 years. This also involved an evaluation of correlations between radiographic and clinical parameters. Twenty-three subjects with 46 interforaminal implants (ITI solid screw implants, 12 mm in length, 4.1 mm in diameter; 10.4 years in situ, range, 8-12.8 years) were investigated. Modified plaque index (mPI), sulcus fluid flow rate (SFFR), modified sulcus bleeding index (mBI), probing depth (PD), distance from implant crown margin to the coronal border of the peri-implant mucosa (DIM), attachment level (AL), width of keratinized mucosa (KM), Periotest values (PTVs) and prosthesis function were evaluated. In the radiographic evaluation, the distance between implant shoulder and first crestal bone-implant contact (DIB) in mm and the horizontal bone loss (HBL) in mm were measured. The relatively high mPI scores (mean, 0.82; score, 0 in 44.4%; SD, 0.83) did not result in increased SFFR scores (mean, 12; min, 3, max, 38; SD, 7.43) or higher mBI scores (mean, 0.35; score, 0 in 70.8%; SD, 0.59), which was commensurate with healthy peri-implant mucosa. A mean PD value of 2.15 mm (min, 1 mm; max, 5 mm; SD, 0.96) and a mean DIM value of 0.28 mm (min, 0 mm; max, 2 mm; SD, 0.52) were measured. The implants were stable, showing a mean Periotest value of -1.91 (max, 02, min, -6; SD, 1.76). A mean DIB of 3.19+/-0.95 mm (range, 1.3-5.16 mm) and a mean HBL of 1.6+/-1.52 mm (range, 0.28-8.33 mm) were calculated. A correlation was found between DIB and the parameters SFFR (P=0.060), DIM (P=0.042), AL (P=0.050) and especially PTV (P<0.01), leading to the assumption that these clinical parameters may be useful indicators of peri-implant bone loss. The results of the 10-year follow-up examination show that non-rigid telescopic connectors with two interforaminal implants for overdenture stabilization appear to be an efficient and effective long-term treatment modality in severely resorbed edentulous mandibles. Particularly in geriatric patient treatment this concept may provide advantages in terms of handling, cleaning and long-term satisfaction.

The extremely resorbed mandible: a comparative prospective study of 2-year results with 3 treatment strategies.
STELLINGSMA K, RAGHOEBAR GM, MEIJER HJ, STEGENGA B., Department of Oral and Maxillofacial Surgery and Maxillofacial Prosthetics, University Hospital, Groningen, The Netherlands.
Int J Oral Maxillofac Implants. 2004 Jul-Aug;19(4):563-77.
PURPOSE: The aim of this prospective clinical study was to compare the clinical and radiographic results of 3 modes of implant treatment in combination with an overdenture in patients with extremely resorbed mandibles. The 3 treatment strategies used were a transmandibular implant, augmentation of the mandible with an autologous bone graft followed by placement of 4 endosseous implants, and the placement of 4 endosseous implants only. MATERIALS AND METHODS: Sixty edentulous patients met the inclusion criteria and were assigned according to a balanced allocation method to 1 of the 3 groups. Postoperative complications, implant survival, periodontal indices, change in mandibular bone height, and prosthetic complications were assessed during a 2-year evaluation period. RESULTS: During the evaluation period significantly more implants were lost in the transmandibular implant and the augmentation groups compared to the group with endosseous implants only. Except for the Bleeding Index and the Periotest values, the periodontal parameters did not differ significantly among the groups. In all 3 groups, there was no significant bone loss at most locations. Minimal prosthetic retreatment was necessary. DISCUSSION: Although implant loss is a frequently used outcome measure for success, the necessity of retreatment seems to be of more relevance for both the patient and the clinician. CONCLUSIONS: The results of this study suggested that patients with extremely resorbed mandibles can be treated with implants alone in this patient population.

Alternative bone expansion technique for immediate placement of implants in the edentulous posterior mandibular ridge: a clinical report.
BASA S, VAROL A, TURKER N., Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Marmara University, Istanbul, Turkey.
Int J Oral Maxillofac Implants. 2004 Jul-Aug;19(4):554-8.
PURPOSE: The aim of this study was to evaluate the effectiveness of a split-crest bone augmentation technique performed for immediate implant placement in thin edentulous posterior mandibular ridges. MATERIALS AND METHODS: In the present study, 125 implants were placed in posterior mandibular ridges of 30 patients. The mandibular buccal walls were split, expanded, and grafted with a combination of platelet-rich plasma and Cerasorb. The split segments were held in place by cortical bone screws. Before loading, periodontal status was checked, implant stability was evaluated with the Periotest, and panoramic radiographs and computerized tomography scans were obtained. Second-stage surgery (cover screw removal and healing abutment placement) was performed after 3 to 4 months. RESULTS: All implants osseointegrated successfully and underwent loading after 4 months. Optimal healing occurred 3 to 4 months earlier than the usual 6 to 9 months required, and no lip paresthesia was noted. DISCUSSION: Although onlay-inlay grafts, sandwich osteotomies, guided bone regeneration, piezoelectricity, and alveolar distraction have been indicated for augmentation in the posterior mandibular region, each of these techniques involves risks and complications. The crest-splitting bone expansion technique enables single-stage immediate implant placement and lateral ridge augmentation in thin crests and may prevent neurosensorial deficiencies. CONCLUSIONS: The split-crest surgical technique is a valid reconstructive procedure for sharp posterior mandibular ridges. If performed using platelet-rich plasma and Cerasorb, it can shorten the osseointegration period.

Early loading (2 or 6 weeks) of sandblasted and acid-etched (SLA) ITI implantsin the posterior mandible. A 1-year randomized controlled clinical trial.
SALVI GE, GALLINI G, LANG NP., University of Berne, School of Dental Medicine, Berne,
Clinical Trial    Randomized Controlled Trial
Clin Oral Implants Res.  2004 Apr;15(2):142-9.
The aim of this 1-year prospective controlled clinical trial was to evaluate theeffect of early loading of ITI solid screw titanium implants with a sandblastedand acid-etched (SLA) surface on clinical and radiographic parameters. MATERIALAND METHODS: Twenty-seven consecutively admitted patients presenting bilateraledentulous posterior mandibular areas and in need of prosthetic reconstructionwere recruited. Sixty-seven ITI standard solid screw implants with an SLAsurface, a diameter of 4.1 mm and a length of 8, 10 or 12 mm were installedbilaterally in molar and premolar areas according to a one-stage surgicalprotocol. One week (test) and 5 weeks (control) after implant placement, solidITI prosthetic abutments were connected using a torque of 35 N cm. Noprovisional restoration was fabricated. Two weeks (test) and 6 weeks (control)after implant placement, porcelain-fused-to-metal single-tooth crowns werecemented. Clinical measurements were obtained at day 0 and 2, 6, 12, 24 and 52weeks thereafter. Periapical radiographs were taken immediately after implantplacement, after 6 weeks and at the 1-year examination. RESULTS: After 1 year,implant survival was 100%. Two test and one control implants rotated at the timeof abutment connection and were left unloaded for 12 additional weeks. At the1-year examination, no statistically significant differences were found betweenthe test and control sites with respect to pocket probing depths (2.6 mm + 0.5vs. 2.7 mm + 0.5), mean clinical attachment levels (3.1 mm + 0.4 vs. 3.2 mm+0.5), mean percentages of sites bleeding on probing (9.7% vs. 8.3%), meanwidths of keratinized mucosa (1.8 mm + 0.4 vs. 1.9 mm + 0.5), mean Periotestvalues (-1.4 PTV + 0.9 vs. -1.6 PTV + 0.8) or mean crestal bone lossmeasurements (0.57 mm + 0.49 vs. 0.72 mm +0.50). CONCLUSION: Based on theseresults, loading of titanium implants with an SLA surface as early as 2 weeksdid not appear to jeopardize the osseointegration healing process in theposterior mandible. Furthermore, implants rotating at 35 N cm, if left unloadedfor additional 12 weeks, did not negatively affect clinical and radiographicoutcomes.

References:  ... 1989    1990    1991    1992  1993    1994    1995    1996    1997    1998    1999    2000    2001    2002
                       2003    2004    2005      2006      ...........


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