In-vitro assessment of the efficiency of cold atmospheric plasma on decontamination of titanium dental implants.

BACKGROUND: The aim of the current study was to comparatively assess the efficiency of three different adjunctive therapy options (cold atmospheric plasma, [CAP], photodynamic therapy [PDT] and chemical decontamination via 35% phosphoric acid gel [PAG]) on decontamination of titanium implant surfaces in-vitro. MATERIALS AND METHODS: Implants were inserted in concavities of four mm in depth mimicking a bone defect at the implant recipient site. In each model, two implants were inserted in the fourth and one implant in the third quadrants. After contamination with E. faecalis, the first group has been treated with CAP for 3 min, the second group with 35% PAG (and the third group with PDT. After treatment, quantification of bacterial colonization was assessed by quantification via colony forming units and qualitatively by fluorescence microscopy and scanning electron microscopy. RESULTS: With a mean value of 1.24 × 105 CFU/ml, the CAP treated implants have showed the least microorganisms. The highest number of CFU was found after PDT with mean value of 8.28 × 106 CFU/ml. For the implants that were processed with phosphoric acid, a mean value of 3.14 × 106 CFU/ml could be detected. When the groups were compared, only the CAP and PDT groups differed significantly from each other (p = 0.005). CONCLUSION: A complete cleaning of the micro-textured implant surface or the killing of the bacteria could not be achieved by any of the investigated treatment options, thus bacteria in the microstructure of the titanium surface cannot be completely reached by mechanical and physico-chemical processes. CLINICAL RELEVANCE: The main goal of the adjunctive peri-implantitis treatment is the decontamination of the implant surface. However, there is still an ongoing need to define the most appropriate adjunctive therapy method. Due to its antimicrobial effects, CAP combined with mechanical debridement could be a feasible treatment modality in the management of peri-implantitis.

Comparative Assessment of the Primary Stability of Straumann BLX Implant Design Using an In Vitro Sinus Lift-Simultaneous Implant Insertion Model.

Straumann BLX is a novel implant system that has been proclaimed to provide an ideal primary stability in all types of bone. In the current study, the primary stability of the Straumann BLX implant systems with Straumann tapered effect (TE) implants have been comparatively assessed in bovine ribs by using a simultaneous sinus elevation and implant insertion model. In the study group, BLX (4.0 × 12 mm), TE (4.1 × 12 mm), BLX (4.5 × 12 mm), and TE (4.8 × 12 mm) were placed in each bony window, which resembles the sinus maxillaris. As a control, BLX and TE implants with the same sizes were inserted into the proximal diaphysis of the bovine ribs. A total of 40 implant insertions were performed. Stability was measured with resonance frequency analysis. In the study group, 4.8-mm TE implants showed significantly higher values compared with 4.5-mm BLX implants (P = .116). However, 4.0-mm BLX implants in the control group showed higher stability compared with 4.0-mm-diameter TE (P = .014). The primary stability of the BLX implants in the control group was significantly higher compared with the experimental group in both widths (P= .018 for BLX 4.0 mm and P = .002 for BLX 4.5 mm, respectively). The use of the TE design with a wide diameter in simultaneous implant placement with sinus lift could present higher implant stability quotient values and might be a more appropriate option for implant recipient sites with poor bone volume and quality. However, the advantage of BLX design in standard implant insertion protocols could be of value.

An experimental study on the effects of the cortical thickness and bone density on initial mechanical anchorage of different Straumann® implant designs.

BACKGROUND: The aim of the current study was to comparatively assess the primary stability of different Straumann® implant designs (BLX, Straumann Tapered Effect, Bone Level Tapered, and Standard Plus) via resonance frequency analysis by using an implant insertion model in freshly slaughtered bovine ribs with and without cortical bone. Tapered Effect (4.1 × 10 mm), Bone Level Tapered (4.1 × 10 mm), Standard Plus (4.1 × 10 mm), and BLX (4.0 × 10 mm) implants were inserted into the distal epiphysis on the longitudinal axis of the freshly slaughtered bovine ribs. As a control, implants with the same sizes were inserted into the proximal diaphysis. The stability of the implants was examined with resonance frequency analysis. RESULTS: BLX and Tapered Effect implants showed higher implant stability quotient values in both study and control groups. All implant systems showed a significant decrease of mechanical anchorage in the study group. BLX and Bone Level Tapered designs had a significantly lower loss of mechanical anchorage in the lack of cortical bone. CONCLUSION: Both Tapered Effect and BLX designs could ensure sufficient initial stability; however, BLX implants could be an appropriate option in the lack of cortical bone and poor bone quality at the implant recipient site. CLINICAL RELEVANCE: BLX is a novel implant system, which could be especially beneficial in the presence of spongious bone type at posterior maxillae.

A Novel Surface Modification Strategy via Photopolymerized Poly-Sulfobetaine Methacrylate Coating to Prevent Bacterial Adhesion on Titanium Surfaces.

Recent investigations on the anti-adhesive properties of polysulfobetaine methacrylate (pSBMA) coatings had shown promising potential as antifouling surfaces and have given the impetus for the present paper, where a pSBMA coating is applied via photopolymerization on a macro-roughened, sandblasted, and acid-etched titanium implant surface in order to assess its antifouling properties. Current emphasis is placed on how the coating is efficient against the adhesion of Enterococcus faecalis by quantitative assessment of colony forming units and qualitative investigation of fluorescence imaging and scanning electron microscopy. pSBMA coatings via photopolymerization of titanium surfaces seems to be a promising antiadhesion strategy, which should bring substantial benefits once certain aspects such as biodegradation and osseointegration were addressed. Additionally, commercial SAL-titanium substrates may be coated with the super-hydrophilic coating, appearing resistant to physiological salt concentrations and most importantly lowering E. faecalis colonization significantly, compared to titanium substrates in the as-received state. It is very likely that pSBMA coatings may also prevent the adhesion of other germs.

Comparison of implant placement accuracy in two different preoperative digital workflows: navigated vs. pilot-drill-guided surgery.

BACKGROUND: The aim of the study is to evaluate the accuracy of a new implant navigation system on two different digital workflows. METHODS: A total of 18 phantom jaws consisting of hard and non-warping plastic and resembling edentulous jaws were used to stimulate a clinical circumstance. A conventional pilot-drill guide was conducted by a technician, and a master model was set by using this laboratory-produced guide. After cone beam computed tomography (CBCT) and 3D scanning of the master models, two different digital workflows (marker tray in CBCT and 3D-printed tray) were performed based on the Digital Imaging Communication in Medicine files and standard tessellation language files. Eight Straumann implants (4.1 mm × 10 mm) were placed in each model, six models for each group, resulting in 144 implant placements in total. Postoperative CBCT were taken, and deviations at the entry point and apex as well as angular deviations were measured compared to the master model. RESULTS: The mean total deviations at the implant entry point for MTC (marker tray in CBCT), 3dPT (3d-printed tray), and PDG (pilot-drill guide) were 1.024 ± 0.446 mm, 1.027 ± 0.455 mm, and 1.009 ± 0.415 mm, respectively, and the mean total deviations at the implant apex were 1.026 ± 0.383 mm, 1.116 ± 0.530 mm, and 1.068 ± 0.384 mm. The angular deviation for the MTC group was 2.22 ± 1.54°. The 3dPT group revealed an angular deviation of 1.95 ± 1.35°, whereas the PDG group showed a mean angular deviation of 2.67 ± 1.58°. Although there were no significant differences among the three groups (P > 0.05), the navigation groups showed lesser angular deviations compared to the pilot-drill-guide (PDG) group. Implants in the 3D-printed tray navigation group showed higher deviations at both entry point and apex. CONCLUSIONS: The accuracy of the evaluated navigation system was similar with the accuracy of a pilot-drill guide. Accuracy of both preoperative workflows (marker tray in CBCT or 3D-printed tray) was reliable for clinical use.

Peri-implant marginal bone loss reduction with platform-switching components: 5-Year post-loading results of an equivalence randomized clinical trial.

AIM: To compare the clinical performance and marginal bone levels of implants restored with platform-switching (PS) or platform-matching (PM) abutments. MATERIALS AND METHODS: Adult patients missing two or more adjacent teeth in the posterior mandible received 2-4 CAMLOG SCREW-LINE implants and were randomly allocated to the PM or PS group, receiving the corresponding prosthetic components from surgery onwards. Implants were conventionally loaded with single cemented crowns. Patients were followed annually for 5 years. Outcome measures were marginal bone level changes, implant survival, performance of the prosthetic components and clinical parameters plaque index, sulcus bleeding index and pocket probing depth. RESULTS: Thirty-three patients received 72 implants in the PM group, and thirty-five patients received 74 implants in the PS group. Sixty patients attended the final appointment, 31 had received PS components and 29 had received PM components with 65 and 63 implants, respectively. Global survival rate was 96.6% with no differences between groups (p = 0.647). After 5 years of functional loading, PS restored implants presented 0.23mm (95% CI: [0.03, 0.43], p = 0.025) lower marginal bone level changes. The two groups were declared non-equivalent. CONCLUSION: Patients requiring implant supported restorations in healed bounded or free end edentulous gaps of the mandible benefit from the use of PS components in terms of peri-implant marginal bone level maintenance, though it may not be clinically noticeable.

Impact of surgical management in cases of intraoperative membrane perforation during a sinus lift procedure: a follow-up on bone graft stability and implant success.

BACKGROUND: Until now, sinus floor elevation represents the gold standard procedure in the atrophic maxilla in order to facilitate dental implant insertion. Although the procedure remains highly predictive, the perforation of the Schneiderian membrane might compromise the stability of the augmented bone and implant success due to chronic sinus infection. The aim of this retrospective cohort study was to show that a membrane tear, if detected and surgically properly addressed, has no influence on the survival of dental implants and bone resorption in the augmented area. METHODS: Thirty-one patients with 39 perforations could be included in this evaluation, and a control group of 32 patients with 40 sinus lift procedures without complications were compared regarding the radiographically determined development of bone level, peri-implant infection, and implant loss. RESULTS: Implant survival was 98.9% in the perforation group over an observation period of 2.7 (± 2.03) years compared to 100% in the control group after 1.8 (± 1.57) years. The residual bone level was significantly lower in the perforation group (p = 0.05) but showed no difference direct postoperatively (p = 0.7851) or in the follow-up assessment (p = 0.2338). Bone resorption remained not different between both groups (p = 0.945). A two-stage procedure was more frequent in the perforation group (p = 0.0003) as well as peri-implantitis (p = 0.0004). CONCLUSIONS: Within the limits of our study, the perforation of the Schneiderian membrane did not have a negative impact on long-term graft stability or the overall implant survival.

Immediate provisionalization in the esthetic zone: 1-year interim results from a prospective single-cohort multicenter study evaluating 3.0-mm-diameter tapered implants.

OBJECTIVES: The aim of this interim analysis of a 5-year prospective multicenter study is to evaluate clinical and radiological performance of immediately provisionalized 3.0-mm-diameter tapered implants. MATERIALS AND METHODS: Patients needing implant rehabilitation of maxillary lateral incisors or mandibular lateral and central incisors were treated with 3.0-mm-diameter implants placed in extraction or healed sites and immediately provisionalized. Clinical and radiographic examinations were performed at implant insertion, 6 months thereafter, and are ongoing. Marginal bone levels and changes, complications, the papilla, plaque, and bleeding indices, and the pink esthetic score (PES) were evaluated at each follow-up visit. RESULTS: Of 112 enrolled patients, 77 patients (91 implants) met the inclusion criteria. Seventy-one patients with 82 implants completed the 1-year follow-up. Three implants failed yielding a CSR of 96.7%. All failures occurred within the first 3 months after implant insertion. Marginal bone level changes from insertion to 6 months was - 0.57 ± 1.30 mm (n = 75) and from insertion to 12 months - 0.25 ± 1.38 mm (n = 72). Fifteen non-serious complications were recorded. Papilla index score and PES improved at the 1-year follow-up. Plaque formation and bleeding-on-probing showed no statistically significant differences between the 6-month and the 1-year visit. CONCLUSIONS: This 1-year analysis demonstrated high survival, stable bone levels, and healthy soft tissue with 3.0-mm-diameter implants. CLINICAL IMPLICATIONS: Narrow diameter implants are a safe and predictable treatment option in patients with limited bone volume and/or limited interdental space and eligible for immediate loading protocols.

Effect of periodontitis history on implant success: a long-term evaluation during supportive periodontal therapy in a university setting.

OBJECTIVES: The aim of this retrospective study was to evaluate the long-term implant survival in patients with a history of chronic periodontitis, during supportive periodontal therapy (SPT), compared to periodontally healthy patients. MATERIALS AND METHODS: Twenty-nine periodontitis patients (test) with SPT for ≥9 years and implant-supported restorations (≥5 years follow-up) were recruited and pair-matched with 29 periodontally healthy patients (control). Subjects in both groups were examined following active periodontal therapy and/or implantation (T1) (test 69 implants, control 76 implants) and at end of SPT or supportive postimplant therapy (T2). Differences between the groups in implant survival (primary outcome), mean marginal bone loss (MBL) and pocket probing depths (PPDs) (secondary outcomes) were evaluated. RESULTS: Implant survival over 5 years was 97.1% in test compared to 97.4% in control group (p = 0.562). MBL was significantly different (test 18.7 ± 18.2%; control 12.5 ± 21.3%) (p < 0.05). PPDs increased at T2 in both groups (test: T1 3.4 ± 1.0 mm; T2 4.2 ± 1.6 mm; control: T1 1.0 ± 1.2 mm; T2 2.9 ± 0.8 mm; p < 0.05 between groups). Prognostic factors for implant loss appeared to be the presence of residual periodontal pockets of ≥4 mm (OR 1.90), bone height (OR 1.81) and age (OR 1.16) at T1. CONCLUSION: In terms of implant survival, no differences were observed between periodontitis and periodontally healthy patients. However, patients with history of periodontitis showed higher MBL and PPDs compared to periodontally healthy patients. CLINICAL RELEVANCE: The presence of a good periodontal maintenance program with preceding successful active periodontal treatment seems to be indispensable components of successful implant treatment in patients with history of chronic periodontitis.

Effect of platform switching on crestal bone levels around implants in the posterior mandible: 3 years results from a multicentre randomized clinical trial.

OBJECTIVE: Evaluation of differences in the clinical performance and crestal bone levels between implants restored with single crowns with platform-matched or platform-switched abutments after 3 years. MATERIAL AND METHODS: The study enrolled adult patients missing two or more adjacent teeth in the posterior mandible with natural teeth mesial to the implant site. Randomization followed open-flap implant insertion and the corresponding matching or switching healing abutments placed at surgery. Conventional loading was made with cemented crowns. Clinical follow-up took place annually after loading up to 3 years. Bone level changes were measured in standardized radiographs as the variation in crestal bone from one evaluation to the next. RESULTS: Sixty-three patients with a total of 135 implants (66 platform matching, 69 platform switching) were analysed. From surgery to 36 months, mean bone loss was 0.28 ± 0.56 mm for the platform-switching group and 0.68 ± 0.64 mm for the platform-matching group. A statistically significant difference was found between groups (p = 0.002) with an estimate of 0.39 mm (0.15-0.64, 95% CI) in favour of platform switching. CONCLUSIONS: After 3 years, platform-switching restorations showed a significant effect in the preservation of marginal bone levels compared to platform-matching restorations.

Long-term Survival of Straumann Dental Implants with TPS Surfaces: A Retrospective Study with a Follow-up of 12 to 23 Years.

PURPOSE: The aim of this study was to evaluate the long-term dental implant survival rates of Straumann dental implants in a university hospital environment over 12 to 23 years. MATERIALS AND METHODS: A total of 388 Straumann dental implants with titanium-sprayed surfaces (TPS) were inserted in 92 patients between 1988 and 1999 in the Department of Oral and Maxillofacial Surgery of the University Hospital Schleswig-Holstein in Kiel, and they were reevaluated with standardized clinical and radiological exams. Kaplan-Meier analyses were performed for individual factors. Cox proportional hazard regression analysis was used to detect the factors influencing long-term implant failure. RESULTS: The long-term implant survival rate was 88.03% after an observation time of 12.2 to 23.5 years. Cox regression revealed statistically significant influences of the International Team for Implantology (ITI) implantation type (p = .00354) and tobacco smoking (p = .01264) on implant failure. A proportion 82.8% of the patients with implant losses had a medical history of periodontitis. Peri-implantitis was diagnosed in 9.7% of the remaining implants in the long-term survey. CONCLUSIONS: This study emphasized the long-term rehabilitation capabilities of Straumann dental implants in complex cases. The survival rates after several years constitute important information for patients, as well as for clinicians, in deciding about different concepts of tooth replacement. Patient-related and technical factors - determined before implant placement - could help to predict the risk of implant loss.

Mechanical properties of collagen membranes: are they sufficient for orbital floor reconstructions?

INTRODUCTION: The most common reconstruction materials for orbital floor fractures are PDS (polydioxanone) foil and titanium meshes. These materials have advantages and disadvantages. Therefore, new materials are needed to improve surgical outcomes. MATERIALS AND METHODS: Three resorbable collagen membranes (Smartbrane(®), BioGide(®), Creos(®)) were tested for their mechanical properties (puncture strength) in mint and artificially aged (3, 6, 8 weeks) conditions and were compared to PDS foil, titanium meshes (0.25 mm, 0.5 mm) and human orbital floors (n = 7). RESULTS: The following puncture strengths were evaluated: human orbital floor, 0.81 ± 0.49 N/mm(2); 0.25 mm titanium mesh, 5.36 ± 0.25 N/mm(2); 0.5 mm titanium mesh, 16.08 ± 5.17 N/mm(2); Smartbrane, 0.74 ± 0.31 N/mm(2); BioGide, 1.65 ± 0.45 N/mm(2); and Creos, 2.81 ± 0.27 N/mm(2). After artificial aging, the puncture strengths were significantly reduced (p ≤ 0.05) at 3, 6 and 8 weeks as follows: Smartbrane, 0.05 ± 0.03 N/mm(2), 0.03 ± 0.02 N/mm(2), and 0.01 ± 0.01 N/mm(2), respectively; BioGide, 0.42 ± 0.06 N/mm(2), 0.41 ± 0.12 N/mm(2), and 0.32 ± 0.08 N/mm(2), respectively; and Creos, 2.02 ± 0.37 N/mm(2), 1.49 ± 0.42 N/mm(2), and 1.36 ± 0.42 N/mm(2), respectively. CONCLUSION: The tested materials showed sufficient puncture strength for orbital floor reconstruction in mint condition. Moreover, after artificial aging, the Creos and BioGide membranes showed sufficient resistance, while Smartbrane showed equivocal data after eight weeks. Therefore, collagen membranes have adequate properties for further in vivo investigations for orbital floor reconstructions.

Platform switch versus platform match in the posterior mandible ­ 1-year results of a multicentre randomized clinical trial.

OBJECTIVE: The purpose of this ongoing randomized study was to assess differences in bone level changes and success rates using implants supporting single crowns in the posterior mandible either with platform matched or platform switched abutments. MATERIAL AND METHODS: Patients aged 18 and above, missing at least two teeth in the posterior mandible and with a natural tooth mesial to the most proximal implant site were enrolled. Randomization followed implant placement. Definitive restorations were placed after a minimum transgingival healing period of 8 weeks. Changes in crestal bone level from surgery and loading (baseline) to 12-month post-loading were radiographically measured. Implant survival and success were determined. RESULTS: Sixty-eight patients received 74 implants in the platform switching group and 72 in the other one. The difference of mean marginal bone level change from surgery to 12 months was significant between groups (p < 0.004). Radiographical mean bone gain or no bone loss from loading was noted for 67.1% of the platform switching and 49.2% of the platform matching implants. Implant success rates were 97.3% and 100%, respectively. CONCLUSIONS: Within the same implant system the platform switching concept showed a positive effect on marginal bone levels when compared with restorations with platform matching.

Highly porous hydroxyapatite with and without local harvested bone in sinus floor augmentation: a histometric study in pigs.

OBJECTIVE: Sinus floor augmentation with autologous bone is an accepted treatment option in dental implantology. In this study, an entirely synthetic, nano-structured, hydroxyapatite-based bone substitute material (SBSM, NanoBone(®); Artoss, Rostock, Germany) was supplemented with a mixture of locally harvested bone to enhance osteogenesis. METHODS: Bilateral sinus augmentation procedures were performed in eight domestic pigs using the lateral window technique. On the right side (control), 2.6 ml of SBSM was used, and on the left side (test), 2.6 ml of SBSM with additional 15% (390 µl) autologous bone was used. At the time of augmentation, a titanium implant (ITI(®)) was inserted from a laterocaudal direction. After 3 months, the sites of augmentation were removed and examined in non-decalcified sections by microradiography and fluorescence microscopy of sequentially labelled specimens and histometry. RESULTS: On both sides, a significant amount of newly formed bone was observed. However, a statistically significant difference in the bone-implant contact was observed in the control group (median, 28.9%) compared with the test side with the additional autologous bone (median, 40.6%) (P = 0.01). Different bone density was achieved from the coronal to apical surfaces (medians, 54.6%, 9.6%, and 27.5%) compared with the test side (medians, 55.2%, 40.6%, and 44.2%). The median of augmentation height was 8.6 mm on the control side and 11.5 mm on the test side (P = 0.01). Bone apposition was observed in both groups after 15 days. CONCLUSION: The SBSM shows acceptable results in sinus floor augmentation. The additional use of locally harvested autologous bone enhances bone density and osseointegration of the implants.

Comparison of two different absorbable membranes for the coverage of lateral osteotomy sites in maxillary sinus augmentation: a preliminary study.

INTRODUCTION: Barrier membranes, both absorbable and non-absorbable, have been used in sinus augmentation for many years. Some years ago, a new autologous blood substrate called Platelet-Rich-Fibrin (PRF) was introduced, and to date, the supporting effect on bone regeneration has been controversial. This study aimed to evaluate the effect of PRF on bone regeneration when used as a barrier membrane at the lateral osteotomy site in sinus augmentation. MATERIAL AND METHODS: Twelve sinuses from six patients requiring bilateral sinus floor augmentation were treated with a two-stage surgical technique using sinus augmentation and implant placement after 5 months. The sinuses were grafted with autologous bone and bone-substitute material (Bio-Oss(®)) mixed in a 1:1 ratio and were covered in a randomized split-mouth design with a PRF or a conventional collagen membrane (Bio-Gide(®)), respectively. Five months later threaded titanium dental implants were inserted and bone specimens harvested with a trephine burr were evaluated histomorphometrically. RESULTS: Bone quality seemed to be equal at both sites of the grafted sinuses. Mean vital bone formation after 5 months was 17.0% and 17.2%, for the PRF and collagen sites, respectively. The mean of residual bone-substitute was 15.9% and 17.3% for PRF and collagen, respectively. No local complications, such as dehiscences or membrane exposures, were detected at either site in any of the treated patients. After 12 months all implants reached primary stability in the augmented maxillary sinus floor without any peri-implant tissue inflammation. CONCLUSIONS: Within the limits of the study the coverage of the lateral sinus window with two different absorbable membranes has been shown to result in a similar amount of vital bone formation and residual bone-substitute.

Regenerative treatment of peri-implantitis bone defects with a combination of autologous bone and a demineralized xenogenic bone graft: a series of 36 defects.

AIM: As the treatment of peri-implantitis-induced bone loss is still a problem, we studied the regenerative treatment of these defects with a mix of autologous bone and a new type of bone graft substitute (demineralized xenogenic bone graft) including growth factors. MATERIAL AND METHODS: In a prospective manner, 36 cases of peri-implantitis-induced bone loss (depth >4 mm) in 22 patients were followed for 1 year. After resolving the acute infection by local rinsing, granulation tissue was removed. The implants were decontaminated with etching gel and the defects were filled with autologous bone mixed 1:1 with a xenogenic bone graft. The prosthetic reconstructions did not have to be removed. Values of probing depths as well as bone defects were analyzed. RESULTS: The radiologic evaluation of the bone defects after regenerative treatment revealed a mean reduction of 3.5 mm comparing the values from 5.1 mm prior to surgery to 1.6 mm 1 year after treatment. Average reduction of the probing depth was 4 mm. The remaining bone defects were larger than 3 mm in 4 out of 36 implants 1 year after treatment. Probing depths of more than 4 mm were present in seven implants. CONCLUSION: Within the limits of the study, we conclude that for bone defects larger than 4 mm in case of peri-implantitis, this single surgical intervention provided a reliable method to reduce bone defects.

Morbidity after iliac crest bone graft harvesting over an anterior versus posterior approach.

PURPOSE: For larger augmentations before implant insertions, as well as spinal arthrodesis surgery, the iliac crest is the standard source of bone grafting. This study assesses iliac morbidity after bone graft harvesting from the anterior and posterior ilium. MATERIALS AND METHODS: A total of 97 patients who underwent corticocancellous iliac crest bone harvesting for augmentations of the jaws from 2004 to 2007 at the Department of Oral and Maxillofacial Surgery, University Hospital Kiel, Kiel, Germany, were included. Their morbidity was assessed with specially designed questionnaires. RESULTS: Pain levels were rated nearly equally on a visual analog scale (1, no pain; 10, strongest pain) by the anterior and posterior groups. At 1 week after bone harvesting, pain was rated 4.9 for the anterior approach and 4.8 for posterior (P = .89). The corresponding values after 6 months were 1.4 and 1.6, respectively (P = .64). Subjective evaluation of the scars showed scores of 2.7 and 3.0, respectively (P = .76). Of the patients, 81% and 88%, respectively, would opt to undergo the operation again. CONCLUSIONS: Patients reported a noticeable reduction in quality of life after elective bone graft harvesting. Nevertheless, nearly all patients would undergo the same procedure again. Both approaches were rated similarly, so for smaller amounts of bone graft needed, the anterior and posterior approaches can be recommended, whereas the posterior approach is suitable for larger amounts.

Prospective observation of 41 perforations of the Schneiderian membrane during sinus floor elevation.

OBJECTIVES: The aim of this study was to follow 41 intraoperative perforations of the Schneiderian membrane during sinus floor elevation and to identify potential differences from patients without perforations. MATERIAL AND METHODS: Two hundred and one sinus floor elevations were performed at the department of oral and maxillofacial surgery of the University Hospital of Schleswig-Holstein in the years 2005 and 2006. Forty-one intraoperative perforations (20.4%) were documented and treated according to the following scheme: defects smaller than 5 mm were covered with a collagen membrane. Larger defects were additionally sutured. Particulated jawbone mixed 50 : 50 with bone substitute (25 cases) and a 50 : 50 mix of particulated iliac crest bone and BioOss (six cases) mainly served as graft material in the perforation group. In 12 cases, implants were installed at the time of sinus grafting, and in 27 cases, a second operation was performed. RESULTS: Four sinus lift procedures had to be discontinued intraoperatively. Over a mean control interval of 162 days, one implant of the 93 inserted had to be replaced in the perforation group. After 1 year, the implant survival rate was 14 out of 14 in the perforation group vs. 81/92 in the control group. CONCLUSIONS: With appropriate treatment, intraoperative sinus membrane perforations did not represent an elevated risk for implant loss, infectious complications or displacement of graft material in the investigated population.