Jean-Pierre Bernard

Osteotome sinus floor elevation technique without grafting material: 3-year results of a prospective pilot study

OBJECTIVE In a prospective pilot study, short< or =10 mm ITI-SLA implants were placed in the resorbed posterior maxilla by means of an osteotome sinus floor elevation (OSFE) procedure without grafting material. This paper presents 3-year data assessing bone-level changes around implants. MATERIAL AND METHODS Twenty-five implants were placed in 17 patients to rehabilitate 16 molar and nine premolar sites. The mean residual bone height (RBH) was 5.4 +/- 2.3 mm. A healing period of 3-4 months was allowed before abutment tightening. Most implants (21/25) were 10 mm long, and the others were 8 and 6 mm long. At the 3-year control, endo-sinus bone gain, implant length protruding into the sinus and crestal bone loss (CBL) were measured on periapical radiographs. RESULTS All implants fulfilled the survival criteria. Despite the absence of grafting material, implants were embedded into newly formed bone tissue. All implants gained endo-sinus bone; the mean gained bone was 3.1 +/- 1.5 mm. The residual protrusion length decreased from 4.9 +/- 2.1 to 1.8 +/- 2.1 mm. CBL was 0.9 +/- 0.8 mm. CONCLUSIONS This study confirms that the OSFE procedure without grafting material is sufficient to create bone beyond the natural limit of the sinus. On the mid-term of 3 years, the technique was found to be predictable in the posterior maxilla when the RBH is limited. Implants gained endo-sinus bone despite the lack of grafting material. Bone gain was still improving over the first-year control. No shrinkage of the augmented area was observed.

Survival rates of short (6 mm) micro-rough surface implants: a review of literature and meta-analysis.

OBJECTIVE The aim of this review was to test the hypothesis that 6 mm micro-rough short Straumann(®) implants provide predictable survival rates and verify that most failures occurring are early failures. MATERIALS AND METHODS A PubMed and hand search was performed to identify studies involving micro-rough 6-mm-short implants published between January 1987 and August 2011. Studies were included that (i) involve Straumann(®) 6 mm implants placed in the human jaws, (ii) provide data on the survival rate, (iii) mention the time of failure, and (iv) report a minimum follow-up period of 12 months following placement. A meta-analysis was performed on the extracted data. RESULTS From a total of 842 publications that were screened, 12 methodologically sound articles qualified to be included for the statistical evaluation based on our inclusion criteria. A total of 690 Straumann(®) 6-mm-short implants were evaluated in the reviewed studies (Total: placed-690, failed-25; maxilla: placed-266, failed-14; mandible: placed-364, failed-5; follow-up period: 1-8 years). A meta-analysis was performed on the calculated early cumulative survival rates (CSR%). The pooled early CSR% calculated in this meta-analysis was 93.7%, whereas the overall survival rates in the maxilla and mandible were 94.7% and 98.6% respectively. Implant failures observed were predominantly early failures (76%). CONCLUSION This meta-analysis provides robust evidence that micro-rough 6-mm-short dental implants are a predictable treatment option, providing favorable survival rates. The failures encountered with 6-mm-short implants were predominantly early and their survival in the mandible was slightly superior.

Osteotome sinus floor elevation technique without grafting: a 5-year prospective study

AIM To evaluate the long-term stability of peri-implant bone formation following implant placement without grafting into resorbed posterior maxillae. MATERIALS AND METHODS Twenty-five implants of 10 mm were placed in 17 patients to rehabilitate atrophic maxillae by means of an osteotome sinus floor elevation (OSFE) procedure without grafting. Mean residual bone height was 5.4±2.3mm. Bone levels were evaluated at 1, 3 and 5 years using periapical radiographs. RESULTS All implants fulfilled survival criteria and gained peri-implant bone (mean increase 3.2±1.3mm). Implant protrusion into the sinus decreased from 4.9±1.9mm after surgery to 1.5±0.9mm after 5 years. Mean crestal bone loss amounting to 0.8±0.8mm stabilized over the 5-year observation interval. Twenty implants showed additional peri-implant bone gain following the 1-year control. CONCLUSIONS Implant rehabilitation of atrophic maxillae may be greatly simplified using implants 10mm and the OSFE technique without grafting. Grafting material is not needed to gain at least 3mm of bone in the atrophic maxilla. The procedure appears predictable with favourable long-term results.

Clinical and histological evaluation of postextraction platelet-rich fibrin socket filling: a prospective randomized controlled study.

Objectives: The aims were to investigate whether the use of platelet-rich fibrin membranes (PRF) for socket filling could improve microarchitecture and intrinsic bone tissue quality of the alveolar bone after premolar extraction and to assess the influence of the surgical procedure before implant placement. Material and Methods: Twenty-three patients requiring premolar extraction followed by implant placement were randomized to three groups: (1) simple extraction and socket filling with PRF, (2) extraction with mucosal flap and socket filling with PRF, and (3) controls with simple extraction without socket filling. Implant placement was performed at week 8, and a bone biopsy was obtained for histomorphometric analysis. Results: Analysis by microcomputed tomography showed better bone healing with improvement of the microarchitecture (P < 0.05) in group 1. This treatment had also a significant effect (P < 0.05) on intrinsic bone tissue quality and preservation of the alveolar width. An invasive surgical procedure with a mucosal flap appeared to completely neutralize the advantages of the PRF. Conclusions: These results support the use of a minimally traumatic procedure for tooth extraction and socket filling with PRF to achieve preservation of hard tissue.

Osteotome sinus floor elevation with and without grafting material in the severely atrophic maxilla. A 1-year prospective randomized controlled study

OBJECTIVES (1) To measure and compare endo-sinus bone levels around implants randomly placed with an osteotome sinus floor elevation (OSFE) procedure in grafted (control) and non-grafted (test) sinuses, (2) to evaluate the OSFE efficacy with short, tapered, and chemically modified hydrophilic surfaced implants in extremely atrophic maxillae, (3) to show that fused corticals may constitute a complication risk. MATERIAL AND METHODS The TE(®) SLActive 8 mm-long implants (Straumann AG) were placed using an OSFE procedure in 4 mm or less of bone height. Healing time before prosthetic rehabilitation was 10 weeks. One year after implant placement, bone levels were measured on standardized periapical radiographs. RESULTS Thirty-seven (17 tests, 20 controls) implants were placed in 12 patients with a mean maxillary residual bone height (RBH) of 2.4 ± 0.9 mm. Before loading, two control implants failed (RBH 1.4 and 1.2 mm); two others rotated at loading (one test, RBH 0.9 mm; one control, RBH 1.5 mm) but were uneventfully loaded after three additional months of healing. These adverse events and complications occurred when implants were placed in merged corticals. Endo-sinus bone gain was 3.9 ± 1.0 and 5.0 ± 1.3 mm for the test and control groups (P = 0.003). The 1-year success rate was 100% and 90%, respectively (P = 0.49). CONCLUSION Although more bone is gained when grafting material is used, this may not be required to promote endo-sinus bone gain. The OSFE procedure with or without grafting material could be efficient when the RBH is ≤ 4 mm. However, when both corticals merged, the risk of complication could increase.

Rehabilitation of the edentulous posterior maxilla after sinus floor elevation using deproteinized bovine bone: a 9-year clinical study.

Objectives:To evaluate the long-term survival rate of rough-surfaced implants placed in maxillary sinuses augmented with deproteinized bovine bone (Bio-Oss; Geistlich Pharma AG, Wolhusen, Switzerland). Materials and Methods:Thirteen maxillary sinuses were augmented in 10 patients with Bio-Oss. After an average healing period of 13.8 months, 24 implants were placed. In 4 cases, biopsies were performed and submitted to histological analysis. Clinical and radiographic evaluation was performed 9 years after implant placement and minimum 8 years after functional loading. Results:At the 9-year control, all the 24 implants were still functional. Thus, the implant survival rate was 100%. Conclusions:Bio-Oss is an acceptable substitute to the autogenous bone, and it can be used as a unique material for sinus floor elevation. Rough-surfaced implants placed in 100% Bio-Oss grafts showed a high survival rate (100%) on the long term. Larger clinical trials are necessary to confirm our results.

Reliability of the vertical magnification factor on panoramic radiographs: clinical implications for posterior mandibular implants

OBJECTIVES Panoramic radiographs allow evaluation of the available bone height for implant treatment planning while imparting a low radiation dose. As panoramic radiography produces image distortion, reference objects are required to determine the exact magnification. This study aims to estimate a panoramic units vertical magnification factor (MF) by measuring the length of dental implants used as radiopaque reference objects on postoperative panoramic radiographs. We compared our findings to the vertical MF listed by the panoramic unit manufacturer, and studied the reproducibility and accuracy of our measuring method by analyzing the inter- and intraobserver agreements. MATERIAL AND METHODS Using a digital calliper, we measured the length of 32 implants on 17 postoperative panoramic radiographs taken with a Scanora unit. The implants were 10mm-long standard Straumann implants placed in the posterior segments of mandibles. The MF was calculated by dividing the implants radiological length by the implants real length. RESULTS The mean calculated vertical MF was 1.27 ± 0.01 (1.245-1.295) and was lower than the manufacturers MF (1.3). The vertical MF was 1.28 ± 0.01 in the premolar and 1.27 ± 0.01 in the molar regions. There was an excellent intraobserver reliability (0.96 for observer 1; 0.93 for observer 2) and a good interobserver reliability (0.85 at measurement session 1; 0.8 at measurement session 2) CONCLUSIONS The observed reliability of the MF confirms that a panoramic radiograph can be used for preoperative implant length evaluation in the posterior mandibular segments. MF stability should be verified with other panoramic units. In clinical practice, using the implant length as a reference object on postoperative panoramic radiographs is a simple and effective evaluation method to estimate a panoramic units MF.

Mechanosensation and maximum bite force in edentulous patients rehabilitated with bimaxillary implant‐supported fixed dental prostheses

OBJECTIVE The aim of this study was to compare tactile sensitivity and maximum voluntary bite force (MBF) of edentulous patients with implant-supported fixed dental prostheses (IFDP/IFDPs) to those wearing complete dentures (CG-CC) and fully dentate subjects (CG-DD). METHODS Seven edentulous subjects with IFDP/IFDPs, seven with CG-CC and seven CG-DD, matched for age and gender, participated in the pilot experiments. Three active tactile thresholds (absolute, 50% and 100%) were evaluated by means of copper foils of decreasing thickness (12 foils: 700-5 μm). The passive thresholds were measured in six different sites per quadrant using a custom-made computer-supported strain gauge. MBF was evaluated electronically using the central-bearing point method. RESULTS Active tactile thresholds were different between all three groups of dental state (Kruskal-Wallis: absolute P = 0.0156; 50% P = 0.0019; 100% P = 0.0059). The active tactile sensitivity with IFDP/IFDPs was between those of the two other groups, except for the 100% threshold. The median passive tactile threshold was higher in patients with IFDP/IFDPs (5.7 N) than in CG-CC (1.7 N) and CG-DD (0.5 N) (Kruskal-Wallis P < 0.0005). MBF did not differ significantly between the dental states (ns). CONCLUSION IFDP/IFDPs are a valuable treatment option for restoring edentulous patients. Limitations concerning their physiological integration into the orofacial system are mainly related to a poor passive rather than active tactile sensitivity or maximum bite force.

Potential adverse events of endosseous dental implants penetrating the maxillary sinus: long-term clinical evaluation.

The aim of this study was to evaluate the nature and incidence of long‐term maxillary sinus adverse events related to endosseous implant placement with protrusion into the maxillary sinus.

Maxillary sinus grafting with a synthetic, nanocrystalline hydroxyapatite-silica gel in humans: histologic and histomorphometric results.

The aim of this study was to evaluate in humans the amount of new bone after sinus floor elevation with a synthetic bone substitute material consisting of nanocrystalline hydroxyapatite embedded in a highly porous silica gel matrix. The lateral approach was applied in eight patients requiring sinus floor elevation to place dental implants. After elevation of the sinus membrane, the cavities were filled with 0.6-mm granules of nanocrystalline hydroxyapatite mixed with the patients blood. A collagen membrane (group 1) or a platelet-rich fibrin (PRF) membrane (group 2) was placed over the bony window. After healing periods between 7 and 11 months (in one case after 24 months), 16 biopsy specimens were harvested with a trephine bur during implant bed preparation. The percentage of new bone, residual filler material, and soft tissue was determined histomorphometrically. Four specimens were excluded from the analysis because of incomplete biopsy removal. In all other specimens, new bone was observed in the augmented region. For group 1, the amount of new bone, residual graft material, and soft tissue was 28.7% ± 5.4%, 25.5% ± 7.6%, and 45.8% ± 3.2%, respectively. For group 2, the values were 28.6% ± 6.90%, 25.7% ± 8.8%, and 45.7% ± 9.3%, respectively. All differences between groups 1 and 2 were not statistically significant. The lowest and highest values of new bone were 21.2% and 34.1% for group 1 and 17.4% and 37.8% for group 2, respectively. The amount of new bone after the use of nanocrystalline hydroxyapatite for sinus floor elevation in humans is comparable to values found in the literature for other synthetic or xenogeneic bone substitute materials. There was no additional beneficial effect of the PRF membrane over the non-cross-linked collagen membrane.