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OBJECTIVES To evaluate the accuracy, safety, and anticipation effect of a novel electrical conductivity device (SG) in maxillary osteotomy preparation for placement of dental implants. MATERIALS AND METHODS Thirty-seven osteotomies were prepared by three operators with different levels of expertise, using the SG protocol in the maxilla of six fresh frozen cadavers. A pre-op CT measurement of the length of bone in the desired implant location was taken and compared with the final length of the osteotomy created using SG during surgery. A comparison was made between the results of the different operators. RESULTS The pre-op CT bone length measurements and the final depth assessment of the osteotomy with SG had a very high correlation level (0.977) with a significant mean difference of 0.639 mm (P

Esthetic considerations are a significant contributing factor in the management of prosthodontic cases and an interdisciplinary approach is often necessary to achieve an optimal result. The visible soft-tissue architecture plays a key role in developing an esthetic smile. Furthermore, an understanding of the relationship between the restorative margin and the gingiva is important for long-term stability of the result. The gingival architecture and gingival health are important for ensuring optimal esthetics following prosthodontic work and close attention to both soft and hard tissues around the teeth, before, during and after restorative procedures, will greatly improve the likelihood of a successful outcome. Moreover, knowing the options available in periodontal plastic surgery is important in esthetic dentistry today. The relevant literature related to restorative and surgical procedures when performing esthetic dentistry are reviewed in this article, and different approaches are illustrated with appropriate cases to explain the treatment approach that was utilized to improve the esthetic appearance of the case.

Objective To histomorphometrically compare the use of collagen-stabilized anorganic bovine bone (ABBM-C) (test) to anorganic bovine bone + autogenous bone (ABBM + AB) (control) in maxillary sinus augmentation. Materials and Methods Forty (n = 40 sinuses) patients underwent sinus augmentation and received either control (20 sinuses) or test bone graft (20 sinuses). Bone samples were harvested from the augmented sinuses 5 months postgrafting. The samples were processed for histomorphometry, which assessed within the primary region of interest (ROI-1), the area fraction of new bone (%NB), graft particle osseointegration (% OI), residual graft (%RG), and soft tissue components (% STM). The same analysis was also carried out in a second region of interest (ROI-2) located in a zone 1 mm proximal to the previous maxillary sinus floor. Results In both ROI-1 and ROI-2, the mean % NB, %RG, and %STM in the control group were similar to mean values in the test group. The % OI was significantly greater in the control group (42.0 +/− 26.8) when compared to the test group (19.6 +/− 27.3) in ROI-2 (P

PubMedID: 25041273 Objectives: The objective of this prospective, controlled clinical study was to determine the outcomes of dental implant therapy with staged guided bone regeneration procedures in patients with type 2 diabetes. Patients and methods: Twenty-four patients were included in the study. Half of the patients were diagnosed with type 2 diabetes mellitus (group 1) while the other half (group 2) of the patients consisted of patients without diabetes. The edentulous maxillary anterior/premolar regions with sufficient vertical height but inadequate horizontal width were treated with staged guided bone regeneration technique and with one or two implant-supported fixed restorations. The patients were followed up at least for 12 months. The parameters that were evaluated were radiographic evaluations on CBCT images and periapical radiographs, histomorphometric analysis, resonance frequency analysis (RFA) and wound-healing parameters. The data were analyzed statistically. Results: A total of 43 implants were placed in 24 patients (22 implants in group 1 and 21 implants in group 2). The survival rates of implants were 100% for both groups. The success rate of implants was 95% for group 1 and 100% for group 2. None of the parameters including CBCT findings, RFA values, success rates and wound-healing scores showed a significant difference between the two groups. Conclusion: Staged guided bone regeneration is a feasible augmentation procedure for the treatment of horizontal bone deficiencies of the maxillary anterior/premolar regions in well-controlled type 2 diabetic patients. © 2015 John Wiley & Sons Ltd.

Objectives Piezoelectric surgery (PS) is meant to be a gentle osteotomy method. The aim of this study was to compare piezosurgical vs. conventional drilling methods for implant site preparation (ISP) – focusing on load-dependent thermal effect on hard tissue and the expenditure of ISP time. Materials and methods Three hundred and sixty ISP were performed on ex vivo pig heads using piezosurgery, spiral burs (SB) and trephine burs (TB). The load applied was increased from 0 to 1000 g in 100-g intervals. Temperature within the bone was measured with a thermocouple, and duration was recorded with a stop watch. Thermal effects were histomorphometrically analysed. Twelve ISPs per technique were performed at the lateral wall of the maxillary sinus. Results PS yields the highest mean temperatures (48.6 ± 3.4°C) and thermal effects (200.7 ± 44.4 μm), both at 900–1000 g. Duration is reduced with a plus of load and significantly longer in either case for PS (P

Objectives The aim of this study was to evaluate the extent and quality of new bone 6 months after sinus lift with biphasic micro- and macroporous calcium phosphate combined with fibrin sealant (MBCP-FS) and the 1-year implant success rate in the augmented site. Material and methods MBCP-FS was applied to one sinus in 96 subjects requiring augmentation for delayed dental implant placement. In subjects who required bilateral lifts (N = 33), the MBCP-FS sinus was randomly selected; the contralateral sinus was grafted with autologous bone (mixed with Bio-Oss when harvested bone volume was insufficient. Panoramic views were taken periodically prior to and up to 18 months post-lift. Histomorphometric analysis was conducted on biopsies taken during implant placement 6 months after augmentation. Implant functionality and prosthesis success were assessed clinically 1 year after implant placement. Results In MBCP-FS sinuses, 20.6 ± 8.5% new, mainly lamellar bone was observed. Implants were placed as planned in 78/85 evaluable subjects (91.8%) 6 months after sinus lift. Graft heights remained stable 1 year after placement; 94.7% (142/150) of implants were functional. The amount and quality of new bone and implant success rates with MBCP-FS were similar to autologous bone graft (mixed with Bio-Oss in 30/31 evaluable subjects). MBCP-FS was safe and well-tolerated. Conclusions MBCP-FS is safe and effective in sinus floor elevation for dental implant placement, supporting bone regeneration and with high 1-year implant success rates similar to autologous bone mixed with Bio-Oss.

Ridge preservation can minimize the loss of alveolar bone subsequent to tooth extraction in preparation for implant therapy. The purpose of this study is to histologically and clinically compare human demineralized bone matrix (DBM) putty with one size of bone particles (SPS) to human DBM putty with two different sizes of bone particles (multiple particle sizes [MPS]) in ridge preservation after molar extractions.Molar tooth extraction and ridge preservation were performed in 20 participants for each treatment group. Approximately 20 weeks after grafting, core biopsies were obtained during implant placement and analyzed under light microscopy. Specimens were analyzed for the percentage area of vital bone, residual graft particles, and non-mineralized structures (connective tissue/other non-mineralized tissue [CT]). Changes in alveolar ridge dimensions were also determined.Sixteen participants in the SPS group and 14 in the MPS group completed the study. The SPS group had a mean of 49% vital bone, 8% residual graft, and 43% CT. The MPS group had 53%, 5%, and 42%, respectively. Patients in both groups lost a mean of1 mm alveolar height on the buccal and lingual aspects and1.5 mm of total ridge width. There were no statistically significant differences between the two groups for any clinical or histologic parameters.The results of this study suggest that addition of larger bone particles to DBM putty does not offer additional benefit in the preservation of alveolar bone after the extraction of molar teeth.

There is limited information regarding marginal bone-level changes around immediately loaded implants placed with the osteotome technique. The aim of this case series is to prospectively evaluate the clinical and radiographic outcome of immediately loaded implants placed with the osteotome technique over a 12-month period.Eighteen patients in need of oral prosthetic rehabilitation that included single implant placement in positions #4 to #13 and/or #20 to #29 participated in this prospective trial. A modified implant installation procedure with an under preparation of the implant bed using the osteotome technique and immediate loading of the implant was performed. Clinical examinations were performed at 2 weeks, 6 months, and 12 months of follow-up. Radiographic examinations were performed at implant installation and at the 6- and 12-month follow-up visits.One implant failed to integrate and was removed at 3 months after implant installation. Four of 20 implants had insertion torque value35 Ncm. The mean marginal bone loss was -0.09 mm at the 6-month and -0.19 mm at the 12-month follow-up visits.The present case series indicates that implants placed with the osteotome technique and immediately loaded did not demonstrate a high insertion torque and exhibited minimal marginal bone loss.

Objectives The purpose of this study was to investigate the effect of simultaneous bone-augmentation procedures, and their combination, on the survival of dental implants and on the incidence of complications. Material and methods Within a retrospective analysis, 958 implants placed in 404 patients (mean age 58.18) were selected from a prospective clinical study. In 304 cases of reduced bone width, bone spreading (n = 217) with hand osteotomes, or bone splitting (n = 15), or guided bone regeneration (n = 72) combined with autogenous bone grafts were also performed. Eighty-eight implants were placed in combination with simultaneous internal sinus floor elevation without using graft material. For 194 additional implants, several augmentation procedures were combined because of extensive bone deficits. Three-hundred and seventy-two conventionally placed implants served as controls. Implant failures and complications were recorded after a mean observation period of 2.1 years (maximum 6.9 years). Results Seventeen failures and nine additional implant-related complications were observed. After 4 years, Kaplan–Meier curves revealed a probability of survival without complication of 97.5% for conventionally placed implants, and 95.8% for implants placed in combination with a single augmentation technique. If several augmentation techniques were combined, success decreased to 94.1%. Complication-free survival differences between combined augmentation techniques and conventionally placed implants were significant (P = 0.004). Age, gender, and location showed no effect on implant survival. Conclusions It can be concluded that simultaneous bone-augmentation techniques slightly reduce short-term prognosis for dental implants. This effect was more pronounced when advanced defects required the combination of several augmentation procedures.

Objectives This study aims to determine differences in primary stability between implants placed in cortical bone following Piezoelectric or conventional site preparation, as assessed by resonance frequency analysis (RFA) and reverse torque testing (RTT). Material and methods Four fresh bovine ribs were acquired and surgical guides fabricated with five sites per rib (n = 20), for proper site preparation. Implant sites were prepared via conventional drilling technique as per manufacturer's instruction (Implantium) or via Piezoelectric (Mectron) implant site preparation using the Implant Prep kit. Twenty 10 mm long, 3.6 mm diameter Implantium implants were placed with 35 Ncm torque; 10 implants per preparation method. RFA was assessed via the Osstell Mentor. Five values were taken per implant. All implants where subjected to a reverse torque in increasing increments of 5 until 50 Ncm force was reached. Results The five RFA values per site were averaged and plotted by placement technique. A paired t-test statistical analysis was run. The average RFA values showed no statistical significance between the 10 test (RFA = 69.04 ± 5.11) and 10 control (RFA = 70.94 ± 6.41) sites (P > 0.05). All implants in both groups withstood RTT up to 50 Ncm force without movement and thus showed no statistical differences. Conclusion Results of this ex vivo study imply that the Piezoelectric implant site preparation affords similar primary implant stability in comparison to conventional rotary instrumentation in cortical bone.

When immediate implant placement is considered for teeth with close proximity to the sinus floor, apical extension of the osteotomy is significantly limited, and often a staged approach is used. Implant placement into fresh extraction sockets and sinus floor manipulation using bone-added osteotome sinus floor elevation with implant placement are techniques most often used independently or sequentially. Very few reports have described the combined use of immediate implant placement in fresh sockets and the bone-added osteotome sinus floor elevation technique.We present five cases in which a maxillary premolar was extracted and an implant placed into the extraction site with simultaneous abfracture of the sinus floor using osteotomes. All teeth were extracted atraumatically, and sockets carefully debrided and checked for integrity of the walls. After ideal osteotomy preparation, particulate bone graft was placed in the osteotomy and appropriately sized osteotomes were used for sinus floor elevation. After sufficient elevation, implant placement was completed and particulate bone was packed in the bone-implant gap when indicated.All implants were restored after a minimum healing period of 6 months. At the time of final restoration, bone was seen surrounding the implants from the apical portion to the most coronal thread. All five implants healed without complications and were in function for periods ranging from 6 to 12 months.Immediate implant placement with simultaneous osteotome sinus floor elevation is an advantageous combination of two successfully used techniques. This combined approach can significantly reduce the treatment time for implant therapy in teeth with close sinus proximity and provide the operator with the ability to place implants of desired length.

Objective: The aim of this study was to determine the clinical efficacy of a mixture of autologous bone harvested from the lateral wall of the maxilla using bone shavers and bovine-derived hydroxyapatite (HA) placed as a graft to elevate the maxillary sinus floor. The histological picture of tissue found in the sinus, the survival rate and the success of the implants were all evaluated. Material and methods: A total of 90 titanium implants were placed in 34 patients. In all of them, the lateral maxillary wall was harvested as a particulate bone graft, subsequently mixed with bovine-derived HA and packed in the sinus cavity. The lateral access window was then covered with a bioresorbable porcine-derived collagen membrane. In 32 sinuses, a two-stage surgery was performed, while in the remaining 10 cases a one-stage surgery was carried out. In the two-stage approach, 14 randomly selected biopsies were obtained at the time of implant insertion after a healing period of 9 months. The histological specimens were histologically and histomorphometrically evaluated. Results: One implant was lost, leading to a survival rate of 98.9%. The new bone consisted of lamellae of living bone contained osteocytes and in close contact with bovine bone particles that were partly infiltrated by newly formed bone. Bovine bone particle resorption could not be found. The histomorphometric analysis showed the following averages: 29% of newly formed bone and 21% of anorganic bovine bone. The marrow spaces made up the remaining 50% of the specimens. Conclusion: Sinus lift graft with autologous bone harvested from the maxillary lateral wall combined with demineralized bovine bone leads to a predictable outcome regarding the amount of bone formation in sinus floor augmentation. To cite this article: de Vicente JC, Hernandez-Vallejo G, Brana-Abascal P, Pena I. Maxillary sinus augmentation with autologous bone harvested from the lateral maxillary wall combined with bovine-derived hydroxyapatite: clinical and histologic observations. Clin. Oral Impl. Res. 21, 2010; 430–438 doi: 10.1111/j.1600-0501.2009.01877.x

Objectives: The objectives of this study were to assess the microvessel density (MVD) of intra-sinus grafts after 6 months of wound healing and to study the relationship between revascularization processes and patient clinical variables and habits. Material and methods: We performed 45 maxillary sinus augmentations with different implant placements in 25 consecutive patients, obtaining bone cores of the grafted area for histological, histomorphometric and immunohistochemical study. Biopsies were also taken from pristine bone in the posterior maxilla (control). Results: All implants survived at 24 months. Biopsies of sinus augmentation areas showed significantly greater remodeling activity vs. pristine bone, with significantly more osteoid lines. The morphometry study revealed 34.88±15.2% vital bone, 32.02±15.1% non-mineralized tissue and 33.08±25.4% remnant anorganic bovine bone particles. The number of CD34-positive vessels was 86.28±55.52/mm2 in graft tissue vs. 31.52±13.69/mm2 in native tissue (P=0.002, Mann–Whitney U=46). The larger amount of non-mineralized tissue in grafts was directly correlated with a higher MVD (r=0.482, P=0.0001, Pearson's test). MVD was affected by the presence of periodontitis or tobacco and alcohol consumption. Conclusion: The angiogenesis and revascularization obtained by this type of graft achieve adequate tissue remodeling for osseointegration and are influenced by periodontal disease and tobacco or alcohol consumption. To cite this article: Galindo-Moreno P, Padial-Molina M, Fernandez-Barbero JE, Mesa F, Rodriguez-Martinez D, O'Valle F. Optimal microvessel density from composite graft of autogenous maxillary cortical bone and anorganic bovine bone in sinus augmentation: influence of clinical variables. Clin. Oral Impl. Res. 21, 2010; 221–227 doi: 10.1111/j.1600-0501.2009.01827.x

Purpose: A lateral approach for sinus elevation using plasma rich in growth factors (PRGF) technology is described. The long-term survival of dental implants installed following a two-stage procedure after sinus elevation using this procedure is reported, using implant loss as the outcome variable. Materials and Methods: A retrospective cohort study design was used. Eighteen patients received 43 implants (BTI implants, Biotechnology Institute, Vitoria, Spain) with sinus floor elevation. All patients presented a residual bone height of class D (1–3 mm). Implants were installed using a low-speed drilling procedure (50 rpm) without irrigation. Finally, the histological and histomorphometric evaluation of eight samples from PRGF grafted sinus involved in the study was carried out 5–6 months posttreatment. Results: The overall survival rate of dental implants was 100%. The mean follow-up period for all implants was 33 ± 7 months ranging from 24 to 44 months. In addition, the histomorphometrical evaluation of the samples evidenced a 25.24 ± 4.62% of vital newly formed bone, 50.31 ± 15.56% of soft connective tissue, and the remaining 24.46 ± 12.79% of bovine anorganic bone. Conclusions: Based on these results, this new approach for sinus elevation and implant installation using PRGF technology can be considered safe, simple, effective, and predictable.

Previous studies have shown that membrane elevation results in predictable bone formation in the maxillary sinus provided that implants can be placed as tent poles. In situations with an extremely thin residual crest which impairs implant placement, it is possible that a space-making device can be used under the sinus membrane to promote bone formation prior to placement of implants.The present study was conducted to test the hypothesis that the use of a space-making device for elevation of the sinus membrane will result in predictable bone formation at the maxillary sinus floor to allow placement of dental implants.Eight tufted capuchin primates underwent bilateral sinus membrane elevation surgery, and a bioresorbable space-making device, about 6 mm wide and 6 mm in height, was placed below the elevated membrane on the sinus floor. An oxidized implant (Nobel Biocare AB, Gothenburg, Sweden) was installed in the residual bone protruding into the created space at one side while the other side was left without an implant. Four animals were sacrificed after 6 months of healing. The remaining four animals received a second implant in the side with a space-making device only and followed for another 3 months before sacrifice. Implant stability was assessed through resonance frequency analysis (RFA) using the Osstell (Osstell AB, Gothenburg, Sweden) at installation, 6 months and 9 months after the first surgery. The bone-implant contact (BIC) and bone area inside the threads (BA) were histometrically evaluated in ground sections.Histologically there were only minor or no signs of bone formation in the sites with a space-making device only. Sites with simultaneous implant placement showed bone formation along the implant surface. Sites with delayed implant placement showed minor or no bone formation and/or formation of a dense fibrous tissue along the apical part of the implant surface. In the latter group the apical part of the implant was not covered with the membrane but protruded into the sinus cavity.The use of a space-making device, with the design used in the present study, does not result in bone formation at the sinus floor. However, membrane elevation and simultaneous placement of the device and an implant does result in bone formation at the implant surface while sites with implants placed 6 months after membrane elevation show only small amounts of bone formation. It is suggested that lack of stabilization of the device and/or a too extensive elevation of the membrane may explain the results.

Background: Maxillary sinus floor elevation surgery is widely used as a preimplantology method to permit implant insertion. Nevertheless, very few data are available about long-term stability of dental implants inserted in grafted sites. Purpose: The aims of the present study were to evaluate the evolution of resonance frequency analysis (RFA) values at 6 and 12 months from the implant insertion in sinus grafted sites and nongrafted sites. Materials and Methods: In 14 patients, 80 Xive implants (Dentsply Friadent GmbH, Mannheim, Germany) were inserted. Sixty-three implants were inserted in a site previously treated with a sinus lift; 17 implants were inserted in healed or postextraction sites. For each implant diameter, length, bone density, insertion torque, and percentage of implant fixed to a nongrafted bone were recorded. RFA values at implant insertion after 6 and 12 months were recorded. Results: After 6 and 12 months, grafted sites showed higher RFA values than the control sites; after 12 months, the difference was statistically significant (.007). A statistically significant positive correlation was found between resonance frequency values and bone quality after 12 months (.05). No statistically significant correlation between RFA values and all the other variables considered was found. Conclusions: Sites treated with sinus lift can offer good long-term stability. After 6 and 12 months, the geometric characteristics of the implant are no longer important to obtain high RFA values, and the bone–implant interface seems to be determinant.

Background: To date, there are still no clear cut guidelines for the use of autogenous bone or bone substitutes. Aim: The aim of the present review was to analyze the current literature in order to determine whether there are advantages of using autogenous bone (AB) over bone substitutes (BS) in sinus floor augmentation. The focused question was: is AB superior to BS for sinus floor augmentation in partially dentate or edentulous patients in terms of implant survival, patient morbidity, sinusitis, graft loss, costs, and risk of disease transmission? Materials and methods: The analysis was limited to titanium implants with modified surfaces placed in sites with 6 mm of residual bone height and a lateral wall approach to the sinus. A literature search was performed for human studies focusing on sinus floor augmentation. Results: Twenty-one articles were included in the review. The highest level of evidence consisted of prospective cohort studies. A descriptive analysis of the constructed evidence tables indicated that the type of graft did not seem to be associated with the success of the procedure, its complications, or implant survival. Length of healing period, simultaneous implant placement or a staged approach or the height of the residual alveolar crest, sinusitis or graft loss did not modify the lack of effect of graft material on the outcomes. Three studies documented that there was donor site morbidity present after the harvest of AB. When iliac crest bone was harvested this sometimes required hospitalization and surgery under general anesthesia. Moreover, bone harvest extended the operating time. The assessment of disease transmission by BS was not a topic of any of the included articles. Discussion and Conclusion: The retrieved evidence provides a low level of support for selection of AB or a bone substitute. Clear reasons could not be identified that should prompt the clinician to prefer AB or BS.

Objectives: To review the literature on mandibular single-implant overdentures (opposing complete maxillary dentures), and present surgical and prosthodontic perspectives of a novel approach for this treatment option. Material and methods: An electronic search through the databases of Pubmed, Embase and Medline using the linked key words ‘mandibular single implant overdentures’ was performed. The search was limited to English language articles published up to August 2008. Hand searches through articles retrieved from the electronic search, peer-reviewed journals and recent conference proceedings were also conducted. Results: A limited number of reports were identified on mandibular single-implant overdentures (opposing maxillary complete dentures). They comprised of case-series reports, short-term prospective trials and current randomized-controlled clinical trials. Different loading protocols with different implant systems have been used, but always with regular diameter implants. Specific anatomical and vascular dangers of the mandibular midline symphysis are identified including a novel surgical approach using a currently available short, wide diameter tapered implant. In addition, the prosthodontic rationale for using a larger attachment system (incorporating a platform switch) for mandibular single-implant overdentures is described. Conclusion: The review reveals that there is a lack of published randomized clinical trials using mandibular single-implant overdentures, opposing maxillary complete dentures. Without the evidence from randomized clinical trials, routine use of this novel approach cannot be recommended, compared with using regular diameter implants and matching attachment systems.

Predictability has been demonstrated for the long-term success of dental implants placed simultaneously with or after a sinus-augmentation procedure. However, the time required to obtain optimal bone formation can be from 6 to 9 months or longer with grafting materials other than autogenous bone. For this reason, there is interest in a surgical technique that does not require the harvest of autogenous bone but still results in sufficient bone formation within a relatively short time frame.The purpose of this case series was to evaluate the bone formation following sinus-augmentation procedures using an allograft cellular bone matrix containing native mesenchymal stem cells. Biopsy and histologic evaluation were performed after approximately 4 months of healing.Histomorphometric analysis revealed an average vital bone content of 33% (range, 22% to 40%) and an average residual graft content of 6% (range, 3% to 7%) for the five cases reported that had an average healing period of 4.1 months (range, 3 to 4.75 months).The high percentage of vital bone content, after a relatively short healing phase, may encourage a more rapid initiation of implant placement or restoration when a cellular grafting approach is considered.

Dento-alveolar trauma often leads to a need for reconstruction of the alveolar crest before an implant can be placed. Although autogenous bone grafts is considered the 'gold standard', this may be associated with patient morbidity and graft resorption. Consequently, the use of bone substitutes has increased. Today, a substantial number of biomaterials are available on the market, but only a few are well documented. The user should be aware that these biomaterials have different properties: resorbable or non-resorbable, time of resorption and resorption mechanism. The purpose of this review is to describe the function of various bone substitutes and indications for their use in reconstructive implant surgery and to give an overview of the current situation.

To assess in a randomized-clinical trial the influence of three augmentation techniques (chinbone with or without a Bio-Gide((R)) membrane and Bio-Oss((R)) with a Bio-Gide((R)) membrane) on the clinical and radiographic characteristics of hard and soft tissues around implants and adjacent teeth in the reconstructed maxillary anterior region, up to 1 year after functional loading.Ninety-three patients requesting single-tooth replacement and presenting with a horizontal (bucco-palatinal) bone deficiency were included. After augmentation, 93 ITI-Esthetic(Plus) implants were placed. Clinical variables, standardized photographs and radiographs were analysed to assess the impact on the levels of the marginal gingiva (MGL) and marginal bone (MBL) around implants and adjacent teeth, viz at pre-augmentation, pre-implantation (TPI) and 1 (T(1)) and 12 (T(12)) months after final crown placement.Implant survival was 97.8%. No significant differences were observed in the treatment outcomes of the three augmentation modalities. Combining the three modalities, a slight but significant increase in the implants approximal pocket depth was found between T(1) and T(12). Approximal bone loss at the implant between T(1) and T(12) was 0.14 +/- 0.76 mm (mesial) and 0.14 +/- 0.47 mm (distal); the approximal MGL slightly increased (mesial: 0.24 +/- 0.46 mm, distal: 0.25 +/- 0.66 mm), and the buccal MGL decreased (0.11 +/- 0.61 mm). Bone loss at the adjacent teeth, although minor, was significant between TPI and T(1). No correlations were observed in changes of MBL and MGL.None of the three applied augmentation technique procedures influenced the characteristics of the MGL and MBL or the implant survival of single-tooth replacements. Peri-implant hard and soft tissues were very stable in the first year after loading.To cite this article:Meijndert L, Raghoebar GM, Meijer HJA, Vissink A. Clinical and radiographic characteristics of single tooth replacements preceded by local ridge augmentation: a prospective randomized-clinical trial.Clin. Oral Impl. Res. 19, 2008; 1295-1303doi: 10.1111/j.1600-0501.2008.01523.x.

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.

Objectives: Computer-based surgical planning allows surgeons to evaluate bone morphology in three dimensions and to perform accurate virtual surgery preoperatively. This study was performed to evaluate the feasibility of using preoperative surgical simulation to enhance the clinical outcome in patients undergoing bi-directional alveolar distraction osteogenesis. Material and methods: Nine patients (mean age, 49 years; range, 20–61 years) with maxillary segmental alveolar defects following post-traumatic atrophy or disuse atrophy after periodontal tooth loss were enrolled in the study. All patients were scheduled for implant placement. Three-dimensional (3-D) morphological evaluation and virtual bi-directional distraction were performed with SimPlant CMF/OMS surgical simulation software (Materialise). In addition, use of an extraosseous bi-directional distraction device (V2-Alveolar Distraction System; Medartis AG) was evaluated during the 3-D alveolar regeneration simulation and resulting augmentation. Results: Alveolar height regeneration and labial-buccal augmentation were planned preoperatively using surgical simulation software. New bone formation with sufficient vertical augmentation of 5.8 mm was observed. As we encountered strong palatal inclination, the angulation required for labial-buccal augmentation during active distraction was the maximum angulation of 40°, even greater than that required in the preoperative simulation of 23.9°. Furthermore, the labial-buccal augmented angulation was gradually decreased to 11.2° at the time of implant placement. In all cases, implantation was successful at the well-augmented sites, with sufficient primary stability after a 3-month consolidation period. Conclusions: Preoperative 3-D simulation is a potentially valuable tool for treatment of the morphologically complicated oral-maxillofacial region. More realistic surgical simulations are anticipated with ongoing effort to collect and integrate clinical data into next-generation software.

Objectives: The aim of the present study was to evaluate the outcome of immediate functional loading of implants in single-tooth replacement using two different installation procedures. Material and Methods: One hundred and fifty-one subjects, who required single-tooth rehabilitation in the area of 15‐25 and 35‐45, were enrolled in eight private clinics in Italy. The implant sites were randomly allocated to one of the following treatment groups. In the control group, in which a standard preparation procedure for implant placement and submerged healing of the implant was used, abutment connection and loading of the implants were performed 3 months after installation. In the test group 1, a standard preparation procedure for the implant placement and immediate functional loading of implant was carried out. In the test 2 group, however, a modified implant installation procedure (osteotome technique) was used followed by immediate functional loading of the implant. Clinical and radiographic examinations were performed at 3 and 12 months of follow-up at all sites. Results: Three implants (5.5%) from the test 2 group (osteotome preparation) and one (2%) from the test 1 group (conventional drill preparation) failed to integrate and were removed one and three months after implant installation. The mean marginal bone loss assessed at 12 months was 0.31mm (test 1), 0.25mm (test 2) and 0.38mm (control) (no statistically significant differences were found between the three treatment groups.) Conclusion: It is suggested that immediate functional loading of implants that are placed with a conventional installation technique and with sufficient primary stability may be considered as a valid treatment alternative in a single-tooth replacement.

INTRODUCTION: This investigation was designed to compare the histomorphometric results from sinus floor augmentation with anorganic bovine bone (ABB) and a new biphasic calcium phosphate, Straumann Bone Ceramic (BCP). MATERIALS AND METHODS: Forty-eight maxillary sinuses were treated in 37 patients. Residual bone width was > or =6 mm and height was > or =3 mm and

Objectives: This study evaluated both the clinical and histological aspects of bone formation in maxillary sinus augmentation using MBCP as the bone-grafting material. Material and methods: MBCP was used as a primary bone substitute for maxillary sinus augmentation. Fifty-two patients were selected after a medical and dental examination, and were divided into the following three groups: those augmented with MBCP only; MBCP combined with irradiated cancellous bone; and MBCP combined with intraoral autogenous bone. After a healing period (average 6.78 months after surgery), bone cores were harvested for a histological evaluation and the implant fixtures were installed. These bone cores were evaluated via light microscope and implants were followed up for at least six months after loading. Results: Four to ten months after surgery, new vital bone surrounding the MBCP particles was observed in 18 bone biopsies. Two out of the 130 implants installed were explanted due to a failure of osseointegration before the prosthetic procedure. All the remaining implants were functioning for 6 to 27 months (average 12.96 months). The cumulative survival rate of the implants was 98.46%. Conclusion: These results show that MBCP can be used as a grafting material for sinus floor augmentation, whether combined with other bone graft materials or not, and lead to a predictable prognosis for dental implants in the posterior maxillary area where there is insufficient vertical height for fixture installation.

Autogenous bone, with its osteogenic, osteoinductive and osteoconductive properties, has long been considered the ideal grafting material in bone reconstructive surgery (26, 85). However, drawbacks ...

Sinus membrane elevation and simultaneous insertion of dental implants : a new surgical technique in maxillary sinus floor augmentation.

Aim: The aim of this study was to test the hypothesis that recombinant human growth and differentiation factor-5 (rhGDF-5) enhances bone formation in sinus floor augmentations in miniature pigs. Material and methods: The maxillary sinus floors in 12 adult female Goettingen minipigs were augmented with β-tricalcium phosphate (β-TCP) on one side. The contralateral test side was augmented using two concentrations of rhGDF-5 (400 μg rhGDF-5/g β-TCP; 800 μg rhGDF-5/g β-TCP) delivered on β-TCP (six animals each). One dental implant was inserted into each sinus floor augmentation. After 4 and 12 weeks, histological and histomorphometric assessment of non-decalcified histological specimens was performed. Results: The results showed significantly higher mean values of volume density (VD) of newly formed bone using the concentration of 400 μg/g β-TCP (22.8%) compared with the respective control (8%) after 4 weeks (P=0.05). The bone-to-implant contact rates were also significantly enhanced after 4 weeks between test sites (400 μg: 41.9%; 800 μg: 40.6%) and control sites (400 μg: 7.8%; 800 μg: 16.4%) (400 μg: P=0.024; 800 μg: P=0.048). Conclusion: It is concluded that rhGDF-5 delivered on β-TCP significantly enhanced early bone formation compared with β-TCP alone in sinus lift procedures in miniature pigs.

Objectives: With natural bovine bone mineral (BioOss®) as carrier, the study aimed at investigating the effect of autogenous osteoblast-like cells on bone regeneration in an orthotopic (maxillary sinus) and an ectopic (muscle) site. Materials and methods: Autogenous osteoblast-like cells were isolated from iliac cancellous bone of six minipigs and expanded in an autogenous serum-supplemented osteogenic medium. After confirmation of osteogenicity, the expanded cells were precultivated on BioOss® granules for 1 week. Four milliliter of cell-seeded BioOss® were used for sinus augmentation of right sinus and a Straumann solid screw (dental) implant was simultaneously installed. The contralateral (control) side was filled with cell-free BioOss®. Besides, 2 ml of the corresponding granules were placed in a pouch in the latissimus dorsi muscles bilaterally. Polychrome sequential labeling was performed postoperatively. Specimens were harvested at week 6. Undecalcified sections were evaluated with microradiography, fluorescence microscopy, histology and histomorphometry. Results: In the test side, the coronal part of dental implant demonstrated higher bone–implant contact (BIC) than the apical part (34.88±28.86% vs. 16.68±13.80%, P=0.039), as well as higher bone density (BD) in the corresponding zone (14.88±6.37% vs. 11.10±4.54%, P=0.021). However, the test side demonstrated no advantage over control side in either BD (12.25±4.22% vs. 8.45±11.04%, P=0.473) or BIC (24.15±21.97% vs. 22.05±19.00%, P=0.270). Rare bone was formed in the muscles in both sides. Conclusions: The expanded autogenous osteoblast-like cells failed to enhance bone formation in the minipig model of sinus augmentation.

Objective: The aim of the present study was to (1) monitor the stability changes of ITI implants placed in atrophic posterior maxillary ridges with osteotome sinus floor elevation (OSFE) without grafting during the first 5 months of healing utilizing resonance frequency analysis (RFA) and (2) determine the factors that affect the implant stability quotient (ISQ) at placement and healings. Material and methods: Forty-two ITI implants were placed in the posterior maxilla in 32 patients with OSFE without bone grafting. The residual vertical bone height ranged from 4 to 8 mm (average 6.36 mm). Bone type was classified into one to four groups according to the Lekholm and Zarb index. ISQ was tested on the day of surgery and consecutively at 2, 4, 6, 8, 12, 16, and 20 weeks by RFA. Results: The 40 osseointegrated implants represented a survival rate of 95.2%. All the 40 implants achieved good primary stability and reached a comparably high stability at 16 weeks postoperation with a dip between 2 and 6 weeks in the stability curve. There was no significant difference of ISQ between type3 and type4 bone at implant placement and follow-up. The mean ISQ and its changing pattern did not demonstrate a statistically significant difference according to the pretreatment vertical bone height and implant length. Conclusions: The findings of this study indicated that uneventful osseointegration may be predictable applying OSFE alone with no grafting in atrophic posterior maxilla. Residual bone height (RBH), implant length, and bone type did not seem to affect the implant stability in this clinical situation.

Aim: The aim of the present study was to evaluate the osseointegration of dental implants and bone formation in maxillary sinus grafting with autologous and anorganic bovine bone in the presence of platelet-rich plasma (PRP) in an established animal model. Material and methods: We performed bilateral maxillary sinus augmentation with 50% anorganic bovine bone and simultaneously inserted a titanium screw implant in five minature pigs. Six hundred microlitre autologous PRP were added to the left side (test). The right side (no PRP) served as control. Polychrome sequential labeling was performed. The animals were sacrificed 6 weeks after surgery. Undecalcified ground sections were evaluated by microradiography, digitized histomorphometry and under fluorescent light. Results: The mean bone implant content in the test and control group was 8.4% and 17.3% respectively (P=0.042). The mean height of newly formed mineralized bone in the augmented area of the test group was 3.6 mm and 5.7 mm respectively (P=0.342). In the PRP group, the mean area of newly formed bone in the base of the sinus was enhanced (75.23%) as compared to the control side (51.8%) (P=0.020*). Although PRP enhanced bone formation at the base of the maxillary sinus, it neither improved osseointegration of dental implants nor bone in-growth into the bone substitute under the selected experimental conditions.

A one-stage surgical technique has been adopted that allows simultaneous implant placement in as little as 1 to 2 mm of residual bone. The aim of this retrospective study was to describe results and complications in sinus augmentation of severely atrophic edentulous maxillae in patients with 1 to 3 mm residual bone height and compare them to a group of patients treated following the standard protocol with residual bone height4 mm.The study consisted of a study group (N = 25) and a control group (N = 30). All patients were consecutive admissions treated for one-stage sinus augmentation by one surgeon during the years 2001 to 2005. Patients' medical files were reviewed mainly regarding operative technical problems and complications.Included in the study were 60 sinuses and 164 simultaneous implants placed in grafted maxillary sinuses. Eight implants failed, seven of which were in the study group; three were in heavy smokers with residual bone of 1 to 3 mm. The success rate was 92% for the study group and 98.7% for the control group. A borderline statistically significant difference was found in the success rates between the groups using the Fisher exact test (P = 0.069).Sinus augmentation with simultaneous implant placement can be used to treat the atrophic maxilla in patients with 1 to 3 mm of vertical residual bone height when careful case planning and surgical techniques are used.

Background: Anorganic bone matrix (ABM) is reported to have osteoconductive properties. No inflammatory or adverse responses have been reported when this material is used in sinus augmentation procedures. ABM is said to be a bioabsorbable biomaterial, but histologic data seem to suggest that the resorption process is slow. Long-term histologic data in humans are lacking. The aim of this case report was to evaluate the bone response to ABM used in maxillary sinus augmentation and retrieved 14 years after surgery. Methods: Titanium dental implants were inserted in two sinuses augmented with ABM. The implants were osseointegrated and functioned well for 14 years. After this period of loading, the connecting screw of one of the implants inserted in the left maxilla broke, and it was necessary to remove the implant. A bone core of the augmented area was harvested separately during the implant removal. Results: A very high quantity of mature, compact bone and a small percentage of residual grafted biomaterial were found. About 5% to 7% of the bone was undergoing remodeling. In most cases, residual ABM particles were surrounded by marrow spaces. In other areas, lamellar bone was found in tight contact with the particle surfaces. Histomorphometry showed that the mean amount of mature, compact bone was 71.0% ± 2.28%, the mean amount of ABM was 22.1% ± 3.18%, and the mean amount of marrow spaces was 11.2% ± 5.42%. Conclusions: ABM seemed to resorb very slowly; after 14 years, only a small quantity of residual grafted particles was present. ABM is an effective graft material for sinus augmentation procedures. Vital, mature bone was formed and maintained over a long period with no chronic inflammatory cell infiltrate, foreign body response, or other adverse effects.

Aim: To evaluate histologically the morphology and characteristics of bone chips harvested intraorally by Safescraper®, a specially designed cortical bone collector. Material and methods: Bone chips harvested near a bone defect or in other intraoral sites were grafted into a post-extractive socket or applied in procedures for maxillary sinus floor augmentation or guided bone regeneration. Core biopsies were performed at implant insertion. Undecalcified specimens embedded in PMMA were studied by histology, histochemistry and SEM. Results: Intraoral harvesting by Safescraper® provided a simple, clinically effective regenerative procedure with low morbidity for collecting cortical bone chips (0.9–1.7 mm in length, roughly 100 μm thick). Chips had an oblong or quadrangular shape and contained live osteocytes (mean viability: 45–72%). Bone chip grafting produced newly formed bone tissue suitable for implant insertion. Trabecular bone volume measured on biopsies decreased with time (from 45–55% to 23%). Grafted chips made up 50% or less of the calcified tissue in biopsies. Biopsies presented remodeling activities, new bone formation by apposition and live osteocytes (35% or higher). Discussion and conclusions: In conclusion, Safescraper® is capable of collecting adequate amounts of cortical bone chips from different intraoral sites. The procedure is effective for treating alveolar defects for endosseous implant insertion and provides good healing of small bone defects after grafting with bone chips. The study indicates that Safescraper® is a very useful device for in-office bone harvesting procedures in routine peri-implant bone regeneration.

The purpose of the present study was the histologic and ultrastructural evaluation of a biomaterial composed of cortical pig bone in the form of granules.After maxillary sinus augmentation using this biomaterial, 10 specimens were retrieved after 5 months in 10 patients using this biomaterial. The specimens were processed to be observed under light microscopy (LM) and transmission electron microscopy (TEM). Histomorphometric measurements were presented by means +/- standard deviations.LM showed that most of the particles were surrounded by newly formed bone. In some areas, the osteoid matrix was present; however, mainly compact bone was present at the interface. There was no evidence of an acute inflammatory infiltrate. The newly formed bone was 36% +/- 2.8% and marrow spaces were 38% +/- 1.6%, whereas residual grafted material was 31% +/- 1.6%. Under TEM, all phases of bone formation (osteoid matrix, woven, and lamellar bone) were observed in proximity with the biomaterial particles. The bone-biomaterial interface showed a close contact between the porcine bone particles and the surrounding bone that had mainly features of mature bone with numerous osteocytes. A lamina limitans was sometimes present at this interface.According to our knowledge, this is the first study presenting data on TEM of a porcine bone-derived biomaterial used in sinus augmentation procedures in humans. Our findings show that this is a biocompatible biomaterial that can be used for maxillary sinus augmentation procedures without interfering with the normal reparative bone processes.

Background: Maxillary sinus augmentation is frequently necessary before placement of dental implants in the posterior maxilla. Besides autogenous bone graft, various bone substitutes have been used, with favourable results. Although platelet-rich plasma (PRP) has been used in the field of oral and maxillofacial surgery for years, its beneficial effects on osseous regeneration still remain unclear. The aim of this study was to evaluate the short and long time effects of PRP on single-stage sinus augmentation using autogenous bone or a fluorohydroxyapatite (Algipore®) in a randomized prospective animal study. Methods: After extraction of maxillary premolars of sixteen minipigs, the wounds were allowed to heal for 2 months. Then, sinus augmentations were performed bilaterally using one of the following grafting materials: autogenous bone and Algipore® with or without PRP. Three dental implants (Ankylos®) were installed in each sinus simultaneously. Four animals were euthanized at each period of observation (1, 2, 8 and 12 months). Implant-bearing specimens were sectioned bucco-lingually along the long axis of implants and undecalcified ground specimens were prepared. The bone-implant-contact (BIC) was measured by means of microradiographic examination. For histological evaluation, the specimens were stained with toluidin blue, and the percentage of the newly formed bone and the remaining bone substitute were evaluated. Results: The grafting materials chosen showed increasing levels of BIC and newly formed bone throughout the period of observation in both PRP and non-PRP groups. Adding PRP resulted in lower BIC and newly formed bone compared with autogenous bone grafts or Algipore® alone. However, a statistical significance was not found. The percentages of the remaining bone substitute in both the PRP and non-PRP groups were closely comparable in all observation periods. Conclusions: The application of PRP could not reveal significant beneficial effects on the BIC, the percentage of the newly formed bone and the remaining bone substitute in this study.

Background: Long-term comparative follow-up studies of dental implants placed in augmented bone are rare. Variations in design and surface roughness have been found to be important for bone integration of implants. However, there is no clinical evidence that such variations lead to an improved clinical outcome. Purpose: To compare two different implant systems used after interpositional bone grafting of the severely resorbed maxilla with a modified augmentation technique using fibrin glue. Materials and Methods: Twenty-two consecutive patients presenting with severe maxillary atrophy underwent reconstruction with Le Fort I osteotomies and interpositional bone grafting. Before placement of bone blocks, the floors of the maxillary sinuses were packed with bone chips mixed with a fibrin glue, to stabilize the graft. After 6 months of graft healing, the first 11 consecutive patients received Branemark System® implants with a turned surface (Nobel Biocare AB, Goteborg, Sweden). The following 11 consecutive patients were treated with Astra Tech implants with a blasted titanium surface (Astra Tech AB, Molndal, Sweden). All patients received fixed prostheses. Marginal bone resorption and donor and recipient site morbidity were evaluated. All patients were clinically and radiographically observed throughout 5 years of functional loading. Results: In the Branemark group, 11 (13%) of 84 placed implants were lost, compared to 4 (5.5%) of 72 placed implants in the Astra Tech group. The difference was not significant. All patients retained fixed constructions after 5 years of loading. The mean marginal bone loss was 2.3 ± 0.8 mm (range, 0–5.0 mm) in the Branemark group and 2.4 ± 1.4 mm (range, 0–7.0 mm) in the Astra Tech group, although again no statistical difference was found. A larger number of implants in the Astra Tech group had a marginal bone resorption of ≥ 3 mm, and implant success in that group was lower than in the Branemark group (52% vs 70%). Conclusion: In this study, reconstruction of the severely resorbed maxilla with Le Fort I osteotomy, interpositional bone grafting, and delayed placement of dental implants was found to be a predictable long-term procedure. Although more implants with a turned surface were lost during the follow-up period, there were no statistically significant differences between turned and titanium blasted implants.

Biological interactions occurring at the bone-biomaterial interface are critical for long-term clinical success. Bio-Oss is a deproteinized, sterilized bovine bone that has been extensively used in bone regeneration procedures. The aim of the present study was a comparative light, scanning, and electron microscopy evaluation of the interface between Bio-Oss and bone in specimens retrieved after sinus augmentation procedures. Under light microscopy, most of the particles were surrounded by newly formed bone, while in a few cases, at the interface of some particles it was possible to observe marrow spaces and biological fluids. Under scanning electron microscopy, in most cases, the particle perimeter appeared lined by bone that was tightly adherent to the biomaterial surface. Transmission electron microscopy showed that the bone tissue around the biomaterial showed all the phases of the bone healing process. In some areas, randomly organized collagen fibers were present, while in other areas, newly formed compact bone was present. In the first bone lamella collagen fibers contacting the Bio-Oss surface were oriented at 243.73 +/- 7.12 degrees (mean +/- SD), while in the rest of the lamella they were oriented at 288.05 +/- 4.86 degrees (mean +/- SD) with a statistically significant difference of 44.32 degrees (p < 0.001). In the same areas the intensity of gray value was 172.56 +/- 18.15 (mean +/- SD) near the biomaterial surface and 158.71 +/- 21.95 (mean +/- SD) in the other part of the lamella with an unstatistically significant difference of 13.79 (p = 0.071). At the bone-biomaterial interface there was also an electron-dense layer similar to cement lines. This layer had a variable morphology being, in some areas, a thin line, and in other areas, a thick irregular band. The analyses showed that Bio-Oss particles do not interfere with the normal osseous healing process after sinus lift procedures and promote new bone formation. In conclusion, this study serves as a better understanding of the morphologic characteristics of Bio-Oss and its interaction with the surrounding tissues.

Background: The Branemark Novum® concept (Nobel Biocare AB, Goteborg, Sweden) was introduced to load implants immediately with a definitive fixed prosthesis in the edentulous mandible. This concept is based on the use of prefabricated templates to allow precise placement of three implants and a prefabricated bar structure for the prosthetic procedure. To obtain three-dimensional stability in these prefabricated templates, surgical bone reduction may be necessary to obtain a stable adaptation between the templates and the recipient bone site. Purpose: The aim of this work was to design a surgical stent for predictable reduction of the residual alveolar crest prior to the implant placement procedures. Materials and Methods: A predetermined alveolar crest platform based essentially on a lateral cephalometric radiographic evaluation was simulated on a cast in order to design a transparent resin surgical guide. The predictability potential of the procedure was then evaluated in 10 patients. The prosthetic outcomes were compared with those of a similar group of 10 patients treated without the presented stent by evaluating two factors, namely, the anterior dimensions of the prostheses and the required posterior adjustments of the upper bar. Results: Correlation analysis of our series suggested a good predictability potential for this procedure (r= 0.9215). The mean anterior prosthetic dimension was 32% lower and was more predictable (narrow range of 8–12 mm vs broad range of 8–21 mm) when the stent was used. Furthermore, since half as many posterior adjustments of the upper bar were required, the laboratory procedure was facilitated. Conclusion: This individualized guide allows appropriate bone reduction for obtaining a predictable surgery and prosthetic stage.

Various maxillary sinus floor augmentation techniques using bone grafts and bone substitutes are frequently used to enable placement of dental implants in the posterior maxilla. A previous case report demonstrated the possibility of promoting bone formation in the sinus by lifting the membrane without using a grafting material. However, the predictability of the technique is not known.The aim of this study was to investigate whether sinus membrane elevation and the simultaneous insertion of titanium implants without additional grafting material constitute a valid technique for bone augmentation of the maxillary sinus floor.The study group comprised 10 patients in whom a total of 12 maxillary sinus floor augmentations were performed. A replaceable bone window was prepared in the lateral sinus wall with a reciprocating saw. The sinus membrane was dissected, elevated superiorly, and sutured to the sinus wall to create and maintain a compartment for blood clot formation. One to three dental implants were inserted through the residual bone and protruded at least 5 mm into the maxillary sinus. The bone window was replaced and secured with the overlying mucosa. Bone height was measured directly at each implant site at the time of insertion. Resonance frequency analysis (RFA) was performed on each implant at the time of initial placement, at abutment surgery, and after 12 months of functional loading. Computed tomography (CT) was performed in the immediate postoperative period and 6 months later, prior to exposure of the implants.A total of 19 implants (Brånemark System, TiUnite, Nobel Biocare AB, Gothenburg, Sweden) in lengths of 10 to 15 mm were placed, with an average residual bone height of 7 mm (range, 4-10 mm). All implants remained clinically stable during the study period. Comparisons of pre- and postoperative CT radiography clearly demonstrated new bone formation within the compartment created by the sinus membrane elevation procedure. RFA measurements showed mean implant stability quotient values of 65, 66, and 64 at placement, at abutment connection, and after 12 months of loading, respectively.The study showed that there is great potential for healing and bone formation in the maxillary sinus without the use of additional bone grafts or bone substitutes. The secluded compartment created by the elevated sinus membrane, implants, and replaceable bone window allowed bone formation according to the principle of guided tissue regeneration. The precise mechanisms are not known, and further histologic studies are needed. Sinus membrane elevation without the use of additional graft material was found to be a predictable technique for bone augmentation of the maxillary sinus floor.

The aim of this prospective study was to document radiographically tissue remodeling patterns around ITI implants placed according to an osteotome technique. In 19 consecutive patients from a private practice, 25 implants of the ITI Dental Implant System were placed subjacent to the sinus floor. Implant beds were pre-prepared with pilot drills and/or using the Summers Osteotome Kit. Bio Oss particles were mixed with autologous bone and inserted into the apex area. Implants were placed self-tapping. The sinus floors were thereby pushed up with attempts not to sever the Schneiderian membrane. Healing occurred submerged or semi-submerged and was uneventful in 24/25 implants. At 1 year, all implants had been restored with crowns or short fixed partial dentures. One implant was lost in the first 3 weeks, but was replaced 6 months later in a second attempt. Intraoral radiographs were obtained presurgically and postsurgically at 3 and 12 months. The mean preoperative distance between the sinus floor and the crest was 7.0 mm (range 2.3-10.3 mm). The mean distances between the implant apex and the initial sinus floor were: 3.66 +/- 1.74 mm mesially and 4.44 +/- 1.62 mm distally. The mean height of the new bone reaching apically and mesially to the implants was 1.52 +/- 2.48 mm at surgery, but was reduced significantly to 1.24 +/- 1.30 mm at 3 months and 0.29 +/- 1.91 mm after 12 months (Hotelling's test P< or =0.01). Similar values were obtained at the disto-apical aspects. In an attempt to assess periapical bone/graft remodeling, a novel index was applied: 0=no bone/graft visible, 1=cloudy appearance of new bone/graft, 2=clearly visible new bone/graft disappearing structures of original sinus floor, 3=new bone/graft with new cortical plate and the former boundary of the sinus floor disappearing. This index increased statistically significantly from baseline to 12 months (Hotelling's test P< or =0.02). In conclusion, this study shows that in areas with reduced bone height subjacent to the sinus, an osteotome technique may provide a minimally invasive way to obtain implant abutments predictably. The grafted area apical to the implants undergoes shrinkage and remodeling. The original boundary of the sinus is eventually consolidated and replaced by a new cortical plate. In addition to the linear measurements, the novel index may assist in assessing periapical remodeling at implants placed with an osteotome technique.

Objectives To evaluate the value of deproteinized bone particles on bone resorption in the augmented space after maxillary sinus floor elevation in rabbits. Material and methods A total of 20 rabbits underwent bilateral grafting, using blood clots (control group) and deproteinized bone particles (experimental group), and followed with histologic and histomorphometric analysis. Results Two weeks after grafting, the augmented space was almost completely obliterated by both newly formed bone and fibrous connective tissue in the control group. Some osteoclasts were found on the surface of newly formed bone, especially near the elevated sinus membrane. In the experimental group, newly formed bone was found along the elevated sinus membrane, the cortical wall of the augmented space, and the surface of deproteinized bone particles near the cortical wall. Some osteoclasts were found along the deproteinized bone particles and a few adhered to the surface of the newly formed bone. Eight to 10 weeks after implantation in the control group, most of the newly formed bone had been resorbed. In the experimental group, newly formed bone was found in most parts of the convex augmented space. Histomorphometrical analysis showed that the augmented height was significantly higher in the experimental group than in the control group at all evaluation times. Bone area was significantly higher in the experimental group than in the control group at 6, 8, and 10 weeks after implantation. The area of grafted deproteinized bone particles did not change significantly from 2 to 10 weeks. Conclusion Slowly resorbed deproteinized bone particles contribute to stable augmentation of the maxillary sinus floor by inhibiting bone resorption.

Since platelet -rich plasma (PRP) has been introduced to the field of oral surgery, it has become a widely accepted additive for bone regeneration treatment. The aim of this study was to evaluate the regenerative capacity of PRP in a sinus graft study on sheep. Twelve adult sheep underwent a bilateral sinus floor elevation procedure with cancellous bone from the iliac crest. Unilaterally, PRP was administrated to the bone graft. After 4 (six sheep) and 12 weeks (six sheep), bone biopsies were obtained from each site. With histomorphometric analysis we evaluated both the percentage of newly formed bone within the grafted site and the percentage of the contact area between the grafted bone and the newly formed bone. After 4 weeks the mean proportion of newly formed bone on the control side was 26.1%, whereas it was 29.2% on the test side. After 12 weeks it was 46.9% on the control side and 51.1% on the test side. The area of contact between the graft and the newly formed bone was 73.0% on the control side and 78.5% on the test side after 4 weeks, and 87.2% on the control side and 90.1% on the test side after 12 weeks. A statistical analysis did not reveal significant differences between the control and the test side. The results of the present experimental study show a regenerative capacity of PRP of quite low potency. Further basic research is needed to investigate more profoundly the possibilities of PRP in bone regeneration.

Previous surgical crown lengthening studies have investigated positional changes of the free gingival margin but not the biological width. Histological studies utilizing animal models have shown that postoperative crestal resorption allowed reestablishment of the biological width. However, very little work has been done in humans. Therefore, the purpose of this study was to evaluate the positional changes of the periodontal tissues, particularly the biological width, following surgical crown lengthening in human subjects.Twenty-three (23) patients who needed surgical crown lengthening to gain retention necessary for prosthetic treatment and/or to access caries, tooth fracture, or previous prosthetic margins entered the study. The following parameters were obtained from line angles of treated teeth (teeth requiring surgical crown lengthening) and adjacent teeth with adjacent and non-adjacent sites: plaque and gingival indexes, free gingival margin, probing depth, attachment level, bone level, direct bone level, and biological width. During surgery, the bone level was reduced based on the future prosthetic margin and predetermined biological width; flaps were placed at the bony crest. Patients were examined at baseline and at 3 and 6 months postoperatively.Eighteen patients completed the study. Overall, the amount of bone resected was 1 to 5 mm. At 90% of treated sites,or = 3 mm of bone was removed. At 3 months, the apical displacement of the free gingival margin at non-adjacent, adjacent, and treated sites was 2.46 +/- 0.25 mm, 2.68 +/- 0.20 mm, and 3.07 +/- 0.16 mm, respectively. There was no significant change in the position of the free gingival margin from 3 to 6 months. The biological width at all sites was smaller at 3 and 6 months compared to baseline (P0.05) except for the treated sites, which were not significantly different from baseline at 6 months.During surgical crown lengthening, the bone level was lowered for placement of the prosthetic margin and reestablishment of the biological width. The biological width, at treated sites, was reestablished to its original vertical dimension by 6 months. In addition, a consistent 3 mm gain of coronal tooth structure was observed at the 3- and 6-month examinations.

Maxillary sinus floor augmentation procedures are currently the treatment of choice when the alveolar crest of the posterior maxilla is insufficient for dental implant anchorage. This procedure aims to obtain enough bone with biomaterial association with the autogenous bone graft to create volume and allow osteoconduction. The objective of this study was to histologically and histometrically evaluate the bone formed after maxillary sinus floor augmentation by grafting with a combination of autogenous bone, from the symphyseal area mixed with DFDBA or hydroxyapatite.Ten biopsies were taken from 10 patients 10 months after sinus floor augmentation using a combination of 50% autogenous bone plus 50% demineralized freeze-dried bone allograft (DFDBA group) or 50% autogenous bone plus 50% hydroxyapatite (HA group). Routine histological processing and staining with hematoxylin and eosin and Masson's trichrome were performed.The histomorphometrical analysis indicated good regenerative results in both groups for the bone tissue mean in the grafted area (50.46+/-16.29% for the DFDBA group and 46.79+/-8.56% for the HA group). Histological evaluation revealed the presence of mature bone with compact and cancellous areas in both groups. The inflammatory infiltrate was on average nonsignificant and of mononuclear prevalence. Some biopsies showed blocks of the biomaterial in the medullary spaces close to the bone wall, with absence of osteogenic activity.The results indicated that both DFDBA and HA associated with an autogenous bone graft were biocompatible and promoted osteoconduction, acting as a matrix for bone formation. However, both materials were still present after 10 months.

Bovine hydroxyapatite (Bio-Oss, Geistlich Pharmaceutical, Wollhausen, Switzerland) has been suggested to be used in maxillary sinus floor augmentation procedures prior to or in conjunction with implant placement. However, the long-term histologic fate of this material is not well understood.The aim with this study was to histologically evaluate the tissue response in patients to a mixture of bovine hydroxyapatite (BH), autogenous bone, and fibrin glue 6 months and 3 years after a maxillary sinus floor augmentation procedure.Biopsies were taken from a group of 20 consecutive patients 6 months (n = 16) and 3 years (n = 12) after maxillary sinus floor augmentation with a mixture of BH (80%), autogenous bone (20%), and fibrin glue and prepared for histologic analysis.Light microscopy and morphometry from biopsies taken after 6 months showed various amounts of mineralized bone tissue. The specimen area was occupied by 54.1 +/- 12.6% nonmineralized tissue, followed by 21.2 +/- 24.5% lamellar bone, 14.5 +/- 10.3% BH particles, and 10.2 +/- 13.4% woven bone. The nonmineralized tissue seen in bone-forming areas consisted of a loose connective tissue, rich with vessels and cells. There were no signs of resorption of the BH particles. The lamellar bone appeared to have originated from the recipient site and was seldom in contact with the BH particles. After 3 years, the nonmineralized tissue area had decreased to 36.0 +/- 19.0% (p.05) and consisted mainly of bone marrow tissue. The surface area of lamellar bone had increased to 50.7 +/- 22.8% (p.05), and there was almost no immature bone. The mean specimen area occupied by BH particles, was 12.4 +/- 8.7% and had not changed from 6 months (not significant). Moreover, the sizes of the particles were similar after 6 months and 3 years. The degree of BH particle-bone contact had increased from 28.8% +/- 19.9% after 6 months to 54.5 +/- 28.8% after 3 years (p.05).Histology of specimens from maxillary sinuses augmented with 80% BH particles, 20% autogenous bone, and fibrin glue showed a positive bone tissue response after 6 months and 3 years after augmentation of the maxillary sinus floor prior to implant placement in a group fo 20 patients. The bone surrounding and in contact with the BH particles after 6 months was mainly immature woven bone, which with time was replaced by mature lamellar bone filling the interparticle space as observed in the 3-year specimens. Moreover, bone-integrated BH particles seem to be resistant to resorption. The results indicate that the procedure may be considered when only small amounts of intraoral autogenous bone graft are available.

Biopsies were taken from 16 out of 20 consecutive referral patients 6 to 8 months after maxillary sinus floor augmentation with a mixture of bovine hydroxyapatite (BH), autogenous bone particles and fibrin glue. Four days prior to biopsy retrieval the patients were given a single dose of tetracycline to label bone forming sites. Fluorescence microscopy of 100 microm thick sections revealed active bone formation in conjunction with the BH particles in 14 of 15 specimens analysed. Light microscopy and morphometry of ground sections from 16 patients showed various amounts of mineralised bone tissue in all except one specimen. In the latter case, the BH particles were encapsulated by a dense fibrous connective tissue. Sections from the augmented areas were occupied by non-mineralized tissue (54.1+12.6%), lamellar bone (21.2+24.5%), BH particles (14.5+10.3%) and woven bone (10.2+13.4%). The non-mineralized tissue seen in bone forming areas consisted of a loose connective tissue, rich of vessels and cells, and in the periphery of a more dense fibrous connective tissue. Woven bone with large and scattered osteocyte lacunae was bridging between the BH particles and the lamellar trabecular bone. There were no signs of resorption of the BH particles. The lamellar bone appeared to have originated from the recipient site and was seldom in contact with the BH particles. It is concluded that the tested implant material has bone conducting properties. The bone associated with the BH particles after 6 to 8 months of healing was mainly woven.

Alveolar bone regeneration is frequently necessary prior to placement of implants. Efforts to improve wound healing have focused on factors that may enhance bone formation following guided bone regeneration (GBR) techniques alone or in combination with bone replacement graft materials. Recent reports suggest that platelet-rich plasma (PRP), presumably high in levels of peptide growth factors, may enhance the formation of new bone when used in combination with autogenous graft material.In this report, the clinical and radiographic results are presented on 15 consecutively treated patients using autologous PRP in combination with freeze-dried bone allograft (FDBA) for sinus elevation and/or ridge augmentation. FDBA and PRP (0.5 g/2cc PRP) were mixed and placed as a composite graft material. A gel formed by mixing autologous thrombin-rich plasma with PRP (1:4 ratio) was used to cover the graft material. Core biopsies of grafted areas were obtained in several patients as part of implant site preparation and were evaluated histologically to determine site maturation.Of 36 implant fixtures, 32 (89%) were considered clinically successful demonstrating complete bone coverage of the implant, no mobility, and a normal radiographic appearance at the time of re-entry and 12 months post-implant exposure. Four implants were removed due to mobility at the time of surgical exposure. Histologic evaluation of biopsy specimens revealed numerous areas of osteoid and bone formation around FDBA particles, with no evidence of inflammatory cell infiltrate.These clinical and histological findings suggest that ridge augmentation and sinus grafting with FDBA in combination with PRP provide a viable therapeutic alternative for implant placements. Future studies are necessary to determine whether PRP enhances new bone formation or maturation with bone replacement allografts.

The osteotome sinus floor elevation is a conservative technique for sinus elevation and immediate implant placement. The purpose of this report is to present a case using the sinus floor elevation technique for placement of a non-submerged implant with 12 months follow-up after permanent restoration and to review the literature regarding sinus floor elevation. The osteotome sinus floor elevation technique may be used successfully for the placement of nonsubmerged implants. It allows for shorter post-treatment waiting times and provides a less invasive approach compared to 1- or 2-step antrostomy procedures.