Histological and radiological outcome after horizontal guided bone regeneration with bovine bone mineral alone or in combination with bone in edentulous atrophic maxilla: A randomized controlled trial.

OBJECTIVE: To assess the radiological and histological outcome after horizontal guided bone regeneration (GBR) with deproteinized bovine bone mineral (DBBM) alone or in combination with particulate autogenous bone (PAB). MATERIALS AND METHODS: Eighteen edentulous patients with an alveolar ridge of ≤4 mm were included in this split-mouth randomized controlled trial. Horizontal GBR with a graft composition of 100% DBBM (100:0) on one side and 90% DBBM and 10% PAB (90:10) on the other side were conducted in all patients. Cone beam computed tomography (CBCT) was obtained preoperatively, immediately postoperative, and after 10 months of healing. Width and volumetric changes in the alveolar process were measured on CBCT. Implants were placed after 10 months of graft healing where biopsies were obtained for histomorphometrical evaluation. RESULTS: The gained widths were 4.9 (±2.4) mm (100:0) and 4.5 (±2.0) mm (90:10) at 3 mm from the top of the crest, and 5.6 (±1.3) mm (100:0) and 4.6 (±2.1) mm (90:10) at 6 mm from the top of the crest. The mean volumetric reductions were 32.8% (±23.8) (100:0) and 38.2% (±23.2) (90:10). Histomorphometry revealed that mean percentages of bone were 50.8% (±10.7) (100:0) and 46.4% (±11.3) (90:10), DBBM were 31.6% (±12.6) (100:0) and 35.4% (±14.8) (90:10), and non-mineralized tissue were 17.6% (±11.7; 100:0) and 18.2% (±18.2) (90:10). No significant differences were evident between in any evaluated parameters. CONCLUSIONS: There were no additional effects of adding PAB to DBBM regarding bone formation, width changes, or volumetric changes after 10 months of graft healing.

Radiographic changes in height and volume after lateral GBR procedures with different ratios of deproteinized bovine bone mineral and autogenous bone at different time points. An experimental study.

OBJECTIVE: Estimate changes in augmentation height and volume after lateral guided bone regeneration (GBR) augmentation with different ratios of deproteinized bovine bone mineral (DBBM) and particulate autogenous bone (PAB) and autogenous bone block (ABB), at different time points. MATERIAL AND METHODS: Twenty-four minipigs were randomly allocated into three healing periods. Lateral augmentation in 96 sites with standardized quantity of graft material was performed with different ratios of DBBM and PAB (50:50, 75:25, and 100:0) and ABB in combination with DBBM, covered by a collagen membrane. Changes in augmentation height and volume were assessed on CT volumes acquired 10, 20, and 30 weeks after surgery. RESULTS: Reduction in bone augmentation height was as follows: 50:50-1.7 mm (-33.1%), 75:25-1.8 mm (-37.8%), 100:0-1.7 mm (-35.8%), and ABB - 0.2 mm (-3.7%), after 30 weeks. The augmentation height was significantly better preserved with ABB compared to 50:50, 75:25, and 100:0, while no significant difference was present among particulate grafts. No significant difference in volumetric reduction was found among 50:50, 75:25, 100:0 and ABB after 30 weeks, while 100:0 presented significant less reduction compared to 50:50, 75:25 and ABB after 10 and 20 weeks. CONCLUSIONS: Augmentation height following GBR was better preserved with ABB covered with DBBM. Addition of PAB to DBBM did not affect the changes in height of the graft. The volumetric stability seems to be comparable for ABB covered by DBBM and all particulate grafts after 30 weeks. However, DBBM alone revealed significant less volume reduction in the early healing phase.

Histological and histomorphometrical outcome after lateral guided bone regeneration augmentation of the mandible with different ratios of deproteinized bovine bone mineral and autogenous bone. A preclinical in vivo study.

OBJECTIVE: To test the hypotheses of no differences in (I) percentage of bone (POB), non-mineralized tissue (NMT), and deproteinized bovine bone mineral (DBBM), and (II) ingrowth of mineralized bone after lateral guided bone regeneration (GBR) augmentation of the mandible with different ratios of DBBM and particulate autogenous bone (PAB) at different time points. MATERIAL AND METHODS: Twenty-four minipigs were randomly allocated into three groups. Lateral augmentation in 96 sites (4 in each animal) was performed unilaterally with a standardized quantity of grafting material in each animal with different ratios of DBBM and PAB (50:50, 75:25, 100:0) and autogenous bone block in combination with DBBM and covered with a collagen membrane. The percentage of different tissues in the graft and ingrowth of mineralized bone was assessed by histomorphometrical and histological analyses after 10, 20, and 30 weeks, respectively. RESULTS: The POB was 54% (50:50), 50% (75:25), and 48% (100:0) after 10 weeks, 60% (50:50), 61% (75:25), and 60% (100:0) after 20 weeks, and 63% (50:50), 62% (75:25), and 62% (100:0) after 30 weeks. There was no significant difference between the groups at any time points. There was a significant increase in POB and a significant decrease in NMT for 75:25 and 100:0 from 10 to 30 weeks. All ratios demonstrated a non-complete ingrowth of mineralized bone into the graft after 10 weeks and complete mineralization after 30 weeks. CONCLUSION: Within the limitations of the present study, it seems like addition of autogenous bone to DBBM for LRA did not affect the bone formation nor graft incorporation after 10-30 weeks of healing. However, a prolonged healing time seems to result in an increased POB for all ratios.

Osteotome-Mediated Sinus Floor Elevation With or Without a Grafting Material: A Systematic Review and Meta-analysis of Long-term Studies (≥5-Years).

OBJECTIVE: To test the hypothesis of no difference in the long-term treatment outcome after osteotome-mediated sinus floor elevation with or without a grafting material. MATERIALS AND METHODS: A MEDLINE/PubMed, Cochrane Library, and EMBASE search in combination with a hand-search of relevant journals was conducted, including human studies published in English from January 1, 1986 to December 1, 2017. RESULTS: One comparative and 7 noncomparative studies fulfilled the inclusion criteria. Survival of suprastructures had never been compared within the same study. Meta-analysis demonstrated an overall estimated patient-based implant survival of 94%. Gain in vertical alveolar bone height was similar with the 2 treatment modalities. Noncomparative studies demonstrated high long-term survival rate of suprastructures and implants with the 2 treatment modalities, as well as limited periimplant marginal bone loss. CONCLUSION: High long-term implant survival was demonstrated after osteotome-mediated sinus floor elevation with or without a grafting material. However, long-term randomized controlled trials comparing the 2 treatment modalities are sparse. Hence, conclusions drawn from this systematic review should be interpreted with caution.

Maxillary Sinus Floor Augmentation With Synthetic Bone Substitutes Compared With Other Grafting Materials: A Systematic Review and Meta-analysis.

OBJECTIVE: To test the hypotheses of no differences in implant treatment outcome after maxillary sinus floor augmentation (MSFA) with synthetic bone substitutes (SBS) compared with other grafting materials applying the lateral window technique. MATERIALS AND METHODS: A MEDLINE/PubMed, Embase and Cochrane Library search in combination with hand-search of selected journals was conducted. RESULTS: Five randomized controlled trials with low risk of bias fulfilled the inclusion criteria. SBS disclosed high survival rate of suprastructures and implants with no significant differences compared to autogenous bone graft or xenograft. Meta-analysis revealed a patient-based implant survival rate of 0.98 (confidence interval: 0.89-1.08), indicating no differences between SBS and xenograft. SBS demonstrated significant less newly formed bone compared with autogenous bone graft, whereas no significant difference was revealed as compared to xenograft. High implant stability values, limited periimplant marginal bone loss, and few complications were reported with SBS. CONCLUSIONS: There seem to be no differences in implant treatment outcome after MSFA with SBS compared to other grafting materials.

Histomorphometric analyses of area fraction of different ratios of Bio-Oss® and bone prior to grafting procedures - An in vitro study to demonstrate a baseline.

OBJECTIVE: The objective of this study was to estimate the area fraction of different ratios of Bio-Oss® and bone, prior to grafting in an in vitro model to demonstrate a histomorphometric baseline. METHODS: Bio-Oss® particles were mixed with autogenous bone from pig jaw in three different ratios (50:50, 80:20 and 100:0) and packed in rice paper in a standardized procedure. Histomorphometric analyses were performed in 25 specimens and 74 regions of interest. The area percentage of Bio-Oss® , bone, and non-mineralized tissue (NMT) were calculated. Results were reported as mean values and 95% confidence interval (CI). RESULTS: The mean area fraction of Bio-Oss® was 20.6% (CI: 18.2-23) in the 50:50 mixture, 33.6% (CI: 29.7-37.6) in the 80:20 mixture, and 43.4% (CI: 40.5-46.3) in the 100:0 mixture. The mean area fraction of NMT was 60.5% (CI: 57.9-63.1) in the 50:50 mixture, 59.6% (CI: 56.4-62.7) in the 80:20 mixture, and 56.6% (CI: 53.7-59.5) in the 100:0 mixture. The mean area fraction of bone was 18.9% (CI: 16.9-20.9) in the 50:50 mixture and 6.8% (CI: 5-8.6) in the 80:20 mixture. CONCLUSION: There is a great difference in the clinically estimated percentage and the histomorphometrically evaluated percentage of Bio-Oss® at baseline, prior to grafting. The area fraction of different tissues presented in this study may be beneficial as guidance for histomorphometrical baseline calculations when different mixtures of Bio-Oss® and autogenous bone are used as grafting materials.

Lateral ridge augmentation with two different ratios of deproteinized bovine bone and autogenous bone: A 2-year follow-up of a randomized and controlled trial.

BACKGROUND: The optimal ratio of deproteinized bovine bone (DPBB) and autogenous bone (AB) for lateral augmentation is presently unknown. PURPOSE: To evaluate implant treatment outcome and radiological graft changes after lateral ridge augmentation with 2 different mixtures of DPBB and AB, 2 years after functional loading. MATERIALS AND METHODS: Thirteen patients were included in a split mouth, randomized, controlled trial. Four partially edentulous and 10 totally edentulous jaws with an alveolar ridge width of <4 mm were augmented with a graft mixture of 90:10 (DPBB:AB) on one side and 60:40 (DPBB:AB) on the contra lateral side. Graft width changes were measured on CBCT scans at different time points. Implant survival and success rates were calculated. Resonance frequency analysis and marginal bone measurements were performed after 2 years of loading. RESULTS: The survival rate was 94.4% for implants installed in the 90:10 and 100% for implants installed in the 60:40. There were no statistically significant differences in survival rate or success rate between the mixtures. The width was 5.7 mm and 6.2 mm, respectively for the 2 groups without any significant difference between the groups after 2 years of loading. There was a significant difference in graft reduction between the groups, 54.4% (90:10) and 37.5% (60:40), respectively. There were no statistically significant differences in implant stability or marginal bone levels at any time points. CONCLUSIONS: The 2 treatment modalities may be successfully used for lateral ridge augmentation and presented good clinical results after 2 years of loading. However, long-term RCTs are required before final conclusions can be provided on this specific topic.

Sinus Floor Augmentation Using Straumann® BoneCeramic™ and Bio-Oss® in a Split Mouth Design and Later Placement of Implants: A 5-Year Report from a Longitudinal Study.

BACKGROUND: Straumann® BoneCeramic™ is a synthetic biphasic calcium phosphate (BCP) aimed for sinus floor augmentation. Long-term follow-up of implants placed in BCP after sinus augmentation is still missing. PURPOSE: The primary aim of the study was to compare survival rates and marginal bone loss of Straumann SLActive implants placed in either BCP (test) or Bio-Oss® (DBB) (control) after sinus floor augmentation. The secondary aim was to calculate graft sinus height at different time points. MATERIALS AND METHODS: Bilateral sinus floor augmentation was performed in a split mouth model. Eleven patients (mean age 67 years) received 100% BCP on one side and 100% DBB on the contralateral side. After 8 months of graft healing, 62 Straumann SLActive implants were placed. After 5 years of functional loading (6 years after augmentation) of implants, marginal bone levels and grafted sinus height were measured, and implant survival and success rates were calculated. RESULTS: After 5 years of loading, all prosthetic constructions were in function although two implants were lost in each grafting material. The overall implant survival rate was 93.5% (91.7% for BCP, 91.3% for DBB, and 100% for residual bone). The success rates were 83.3% and 91.3% for BCP and DBB, respectively. There was no statistically significant difference in mean marginal bone level after 5 years between BCP (1.4 ± 1.2 mm) and DBB (1.0 ± 0.7 mm). Graft height reduction (GHR) after 6 years was limited to 6.6% for BCP and 5.8% for DBB. CONCLUSION: In this limited RCT study, the choice of biomaterial used for sinus floor augmentation did not seem to have any impact on survival rates and marginal bone level of the placed implants after 5 years of functional loading and GHR was minimal.

Four-Millimeter-Long Posterior-Mandible Implants: 5-Year Outcomes of a Prospective Multicenter Study.

BACKGROUND: There is lack of evidence on long-term success of short dental implants in reduced alveolar bone. PURPOSE: In this prospective 5-year study, survival and marginal bone loss of 4-mm implants, which supported fixed dental prostheses (FDPs) in severely resorbed posterior mandibles, were evaluated. MATERIAL AND METHODS: In 28 patients, evaluation of 86 osseointegrated 4-mm-long implants, which supported a 3- or a 4-unit FDP by crown splinting without the use of pontics or cantilevers, was performed over a 5-year period. RESULTS: Three subjects dropped out for non-study reasons: one subject had her three implants removed after 1 year and two subjects died (six implants). Five implants in three subjects were lost between 3 and 5 years. Twenty-four subjects and 71 implants were active at the 5-year follow-up (92.2% survival). After 1 year, significant (p < .001) mean (standard error of the mean [SEM]) 0.44-mm (0.05) marginal bone loss occurred. At 2, 3, and 5 years, mean (SEM) bone loss of 0.57 mm (0.06), 0.55 mm (0.07), and 0.53 mm (0.08) occurred, respectively (no significant change after 1 year). At 5 years, average plaque levels were 13.3%; 69% of the implants were plaque free. On average, mucosal bleeding occurred at 8.1% of the implants. During 5 years, two subjects experienced uncomplicated bridge loosening. No other complications occurred during the study. CONCLUSION: Four-millimeter implants can support FDPs in severely resorbed posterior mandibles for 5 years with healthy peri-implant conditions.

A randomized and controlled clinical trial of two different compositions of deproteinized bovine bone and autogenous bone used for lateral ridge augmentation.

OBJECTIVE: The aim of the study was to radiologically and histologically evaluate the graft healing and volumetric changes after lateral augmentation with two different compositions of deproteinized bovine bone (DPBB) and autogenous bone (AB). MATERIAL AND METHODS: Thirteen patients with a mean age of 59.6 ± 12.1 years (six men and seven women) were included in this randomized and controlled trial, designed as a split-mouth study. Ten edentulous and four partially edentulous jaws with an alveolar ridge width of ≤4 mm were laterally augmented with a graft composition of 60 : 40 (DPBB/AB) on one side and 90 : 10 (DPBB/AB) on the contralateral side. Cone beam computed tomography (CB/CT) was obtained immediately postoperatively and after a healing period of 7.5 months. Width changes were measured on CB/CT scans. After a mean healing period of 8.1 months (range, 7.9-8.3), biopsies were retrieved perpendicular to the crest from each graft by means of a trephine bur. Histomorphometry was performed, and the following variables were recorded: Ingrowth of new bone (percentage of total graft width), percentage of DPBB, bone and soft tissue, and percentage of DPBB particles in contact with bone. RESULTS: The mean gained width of the alveolar crest after 7.5 months was significantly more for the 60 : 40 mixture compared with the 90 : 10 mixture, 3.5 (±1.3) mm and 2.9 (±1.3) mm, respectively. There was a significant difference in graft width reduction between 60 : 40 and 90 : 10 after 7.5 months, 37 (±19.9)% and 46.9 (±23.5)%, respectively. New bone ingrowth had occurred in 82.1 (±23.3)% and 82.3 (±26.6)% of the graft, respectively. There were no statistical differences between fractions of different tissues between the 90 : 10 and 60 : 40 compositions. However, there were significantly more soft tissue and less new bone formation closer to the periosteum compared with the graft portion closer to the residual bone in both 60 : 40 and 90 : 10 compositions. CONCLUSIONS: There was significantly less graft width reduction with a mixture of 60 : 40 (DPBB/AB) compared with a mixture of 90 : 10 composition, but the results from the histomorphometry showed no statistical differences comparing the groups.

A 10-year clinical and radiographic study of implants placed after maxillary sinus floor augmentation with an 80:20 mixture of deproteinized bovine bone and autogenous bone.

BACKGROUND: There is a need for prospective, long-term follow-up studies of implants placed after maxillary sinus floor augmentation (MSFA). PURPOSE: The aim of the present study was to determine whether deprotenized bovine bone (DPBB) used for MSFA may result in long-term stability of placed dental implants. MATERIAL AND METHODS: Fourteen of the 20 patients included in the study were followed throughout the 10 years study period. These patients had 53 implants placed in 22 (6 unilateral and 8 bilateral) maxillary sinuses augmented with a mixture of 80% DPBB and 20% autogenous bone (80:20), and 15 implants placed in non-grafted sites. Clinical and radiographic examinations of the implants and grafts were performed. RESULTS: After 10 years of functional loading 15 of the initially placed 108 implants had been lost giving a cumulative survival rate of 86%. The mean marginal bone loss was 1.6 ± 1.0 mm. There were no statistically significant differences in marginal bone level, pocket depth, or ISQ-values between implants placed in residual or grafted bone or between smokers or non-smokers at 10 years follow-up. There was a statistically significant reduction (p < .01) in graft height between 3 months and 2 years but no further significant reduction up to 10 years. CONCLUSIONS: The first 2 years after placement of implants with turned surfaces placed in sites after sinus floor augmentation with DPBB and autogenous bone seem to be critical for implant survival. At 10 years follow-up, the remaining implants presented excellent clinical and radiological results regardless of smoking habits or implant sites (augmented or residual bone).

A 3-year clinical follow-up of implants placed in two different biomaterials used for sinus augmentation.

PURPOSE: The aims of the present study were to compare a novel biphasic calcium phosphate (BCP) with deproteinized bovine bone (DBB) for maxillary sinus floor augmentation in a split-mouth design and to perform a clinical follow-up of dental implants placed in the augmented sinuses. MATERIALS AND METHODS: Partially or completely edentulous patients requiring bilateral sinus augmentation were included in the study. The patients were randomized for augmentation with BCP (test) and DBB (control) in the contralateral side. Eight months after grafting, dental implants were placed. After 3 years of graft healing, core biopsy specimens were obtained from the grafted areas for histologic and histomorphometric analyses. After 3 years of functional implant loading, implant survival/success rates and clinical indices were assessed and radiographic examination and resonance frequency analysis were performed. RESULTS: Nine completely edentulous patients and two partially edentulous patients (mean age, 67 years) who required bilateral sinus augmentation were included in the study, and 62 implants were placed. The mean values for the area of newly formed bone in the retrieved specimens were 29% ± 14.3% and 32% ± 18.0% for BCP and DBB, respectively; the percentage of graft particles in contact with bone was 38% ± 10.9% in the BCP group and 44% ± 12.1% in the DBB group (no statistical significant differences between groups). The mean values for the area of BCP particles and DBB particles were 20% ± 7.5% and 24% ± 13.5%, respectively (difference not significant). One dental implant was lost from each group, resulting in an overall implant survival rate of 96.8% after 3 years of loading. CONCLUSION: After 3 years, a similar amount of newly formed bone was present regardless of the biomaterial used. The choice of biomaterial did not seem to influence implant survival rates.

Four-millimeter implants supporting fixed partial dental prostheses in the severely resorbed posterior mandible: two-year results.

BACKGROUND: Reduced alveolar bone volume complicates implant dentistry. PURPOSE: In this prospective multicenter study, a new, 4-mm long Straumann SLActive implant (Ø 4.1 mm) supporting a fixed dental prosthesis (FDP) in the severely resorbed posterior mandible was evaluated for two years. MATERIAL AND METHODS: Thirty-two patients (11 men, 21 women; mean age 64.1 years) participated. Ten to 12 weeks after single-stage surgery, a screw-retained FDP was attached to three or four 4-mm implants. RESULTS AND DISCUSSION: One hundred implants were inserted. Three failed at surgery and four were lost before loading. Twenty-eight patients received FDPs (93 implants). Two patients were discontinued because of secondary exclusion criteria; therefore, 26 patients were followed up from baseline (BL). After 1 year, one patient insisted on removal of all implants and one patient died because of nonstudy-related complications. Twenty-four patients (87 implants) were eligible for examination 2 years post-loading. All implants were found to be stable [survival rate 95.7% (confidence interval, CI 88.8-98.3) after 1 year and 92.3% (CI 84.5-96.2) after 2 years]. The mean change from BL to 12 months was - 0.43 mm (CI 0.31-0.59; p < .001) and from 12 to 24 months - 0.11 mm (CI -0.01-0.23; p = .056). The survival rate is only slightly lower than in similar studies on 6 to 8.5 mm implants. This may be related to high initial stability and effective use of the residual bone volume with high primary bone-to-implant contact in dense bone structures. The surgical handling of the tested implant was found to be similar to that of implants of common length. However, the preparation procedure must be done with great care to avoid overdrilling. Careful planning and design of the prosthetic construction is mandatory to prevent unfavorable occlusion and avoid harmful shear forces. CONCLUSION: This study showed that 4 mm implants can support an FDP in severely resorbed posterior mandibles for at least 2 years and with healthy peri-implant conditions.

A prospective 1-year clinical and radiographic study of implants placed after maxillary sinus floor augmentation with synthetic biphasic calcium phosphate or deproteinized bovine bone.

BACKGROUND: The technique of using bone grafts or different biomaterials for augmentation of the maxillary sinus prior to implant placement is well accepted by clinicians. However, clinical documentation of some bone substitutes is still lacking. PURPOSE: This prospective study was designed to evaluate the success rate of implants placed after maxillary sinus augmentation with a novel synthetic biphasic calcium phosphate (BCP) or deproteinized bovine bone (DBB), the latter acting as control. MATERIAL AND METHODS: Nine edentulous patients and two partially edentulous patients with a mean age of 67 years with a bilateral need for sinus augmentation, < 5 mm residual bone in the floor of the sinus and a crestal width ≥ 4 mm, were included in the study. After bilateral elevation of the Schneiderian membrane, all patients were randomized for augmentation with synthetic BCP in one side and DBB in the contralateral side. After 8 months of graft healing, 62 implants with an SLActive surface were placed. Implant survival, graft resorption, plaque index, bleeding on probing, sulcus bleeding index, probing pocket depth, and implant success rate were evaluated after 1 year of functional loading. RESULTS: After a mean of 118 days, all patients received their fixed prosthetic constructions. One implant was lost in each biomaterial, giving an overall survival rate of 96.8%. Success rates for implants placed in BCP and DBB were 91.7 and 95.7%, respectively. No significant difference in marginal bone loss was found around implants placed in BCP, DBB, or residual bone, respectively. The mean graft resorption was 0.43 mm (BCP) and 0.29 mm (DBB). CONCLUSION: In this limited study, implant success rate was not dependent on the biomaterial used for maxillary sinus augmentation. Similar results were found after 1 year of functional loading for implants placed after sinus augmentation using BCP or DBB.

Tissue reactions to subperiosteal onlays of demineralized xenogenous dentin blocks in rats.

OBJECTIVES: This study was undertaken to examine the influence of partial demineralization of xenogenous dentin on bone formation in an osteoconductive environment. MATERIALS AND METHODS: Sixty dentin blocks, 2-3 mm thick and 4 mm in diameter, were prepared from developing teeth of young pigs. Forty blocks were demineralized in 24% ethylenediaminetetraacetic acid (pH 7.0) for 1, 2, 6 or 12 h. Forty adult rats divided into eight groups with five rats in each group were used. A sagittal midcranial incision was made from the occipital to the frontal region. Through a subperiostal dissection, a pocket was created on each side of the skull. One demineralized block was placed on one side, and a non-demineralized block was placed on the contralateral side, or the pocket was left empty as controls. Thus, eight experimental groups with five rats in each were formed. RESULTS: Resorption increased significantly with increasing degree of demineralization while bone formation increased significantly with increasing degree of demineralization, provided inflammation was compensated for. This suggests an important role for inflammation or infection control during the healing period of osteogenic implants to optimize osseous integration in an osteoconductive environment. CONCLUSION: Partial demineralization of xenogenous dentin blocks may provide a method for optimizing the integration of dentin onlays in an osteoconductive environment, thus stabilizing the implant and slowing down replacement resorption.

Histological and histomorphometrical analyses of biopsies harvested 11 years after maxillary sinus floor augmentation with deproteinized bovine and autogenous bone.

OBJECTIVE: The purpose of the present study was to histologically and histomorphometrically evaluate the long-term tissue response to deproteinized bovine bone (DPBB) particles used in association with autogenous bone and to compare particle size after 6 months and 11 years, in the same patients, in order to determine possible resorption. MATERIAL AND METHODS: Twenty consecutive patients (14 women and six men) with a mean age of 62 years (range 48-69 years) with severe atrophy of the posterior maxilla were included in this study. Thirty maxillary sinuses with <5 mm subantral alveolar bone were augmented with a mixture of 80% DPBB and 20% autogenous bone. Eleven years (mean 11.5 years) after augmentation, biopsies were taken from the grafted areas of the 11 patients who volunteered to participate in this new surgical intervention. The following histomorphometrical measurements were performed in these specimens: total bone area in percentage, total area of the DPBB, total area of marrow space, the degree of DPBB-bone contact (percentage of the total surface length for each particle), the length of all DPBB particles and the area of all DPBB particles. The length and the area of the particles were compared with samples harvested from the same patients at 6 months (nine samples) and pristine particles from the manufacturer. RESULTS: The biopsies consisted of 44.7+/-16.9% lamellar bone, 38+/-16.9% marrow space and 17.3+/-13.2% DPBB. The degree of DPBB to bone contact was 61.5+/-34%. There were no statistically significant differences between the length and area of the particles after 11 years compared with those measured after 6 months in the same patients or to pristine particles from the manufacturer. CONCLUSION: DPBB particles were found to be well integrated in lamellar bone, after sinus floor augmentation in humans, showing no significant changes in particle size after 11 years. To cite this article: Mordenfeld A, Hallman M, Johansson CB, Albrektsson T. Histological and histomorphometrical analyses of biopsies harvested 11 years after maxillary sinus floor augmentation with deproteinized bovine and autogenous bone.

Bone replacement following dental trauma prior to implant surgery--status.

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.

Clinical histology of microimplants placed in two different biomaterials.

PURPOSE: This randomized, controlled study was designed to compare bone formation around microimplants with a sandblasted, acid-etched surface placed at the time of maxillary sinus floor augmentation with a synthetic biphasic calcium phosphate (BCP) or deproteinized bovine bone (DBB). MATERIALS AND METHODS: Nine completely edentulous patients and two partially edentulous patients (six women, five men) with a mean age of 67 years (range, 50 to 79 years) requiring bilateral sinus augmentation were included in the study. The patients were randomized for augmentation with BCP (test) in one side and DBB (control) in the contralateral side. At the time of augmentation, one microimplant on each side was placed vertically from the top of the alveolar crest, penetrating the residual bone and the grafting material. After 8 months of graft healing, at the time of ordinary implant placement, all 22 microimplants were retrieved with a surrounding bone core for histologic analyses. RESULTS: The bone-to-implant contact in the BCP group was 64.6% +/- 9.0%, versus 55.0% +/- 16.0% for the DBB group. The difference was not significant. The corresponding values for the area of newly formed bone in the biopsies were 41.1% +/- 9.8% and 41.6% +/- 14.0% for BCP and DBB, respectively. There were significantly more DBB particles in contact with newly formed bone than BCP particles (87.9 +/- 18.2% versus 53.9 +/- 26.1%; Wilcoxon rank sum test; P = .007). CONCLUSION: In this randomized, controlled clinical trial, new bone formation and bone-to-implant contact around microimplants with a sandblasted, acid-etched surface was found to be equivalent between sinuses augmented with BCP or DBB. Significantly more DBB particles than BCP particles were in contact with newly formed bone, but the clinical relevance of this has yet to be established.

A retrospective 5-year follow-up study of two different titanium implant surfaces used after interpositional bone grafting for reconstruction of the atrophic edentulous maxilla.

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 Brånemark System implants with a turned surface (Nobel Biocare AB, Göteborg, Sweden). The following 11 consecutive patients were treated with Astra Tech implants with a blasted titanium surface (Astra Tech AB, Mölndal, 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 Brånemark 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 Brånemark 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>or=3 mm, and implant success in that group was lower than in the Brånemark 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.