The new bone formation in human maxillary sinuses using two bone substitutes with different resorption types associated or not with autogenous bone graft: a comparative histomorphometric, immunohistochemical and randomized clinical study

Abstract Objective The aim of this study is to evaluate the new bone and connective tissue formation and the biomaterial remaining after maxillary sinus bone augmentation using 5 different bone substitutes. The osteocalcin immunolabeling was performed to demonstrate their calcification and the possibility of receiving dental implants. Methodology 40 patients underwent maxillary sinus bone augmentation and were divided in 5 groups: Group 1 with 8 maxillary sinuses were grafted with autogenous bone graft (AB); Group 2 with 8 maxillary sinuses grafted with bioactive glass (BG); Group 3 with 8 maxillary sinuses grafted with bioactive glass added to autogenous bone graft (BG + AB) 1:1; Group 4 with 8 maxillary sinuses grafted with Bio-Oss (BO) and Group 5 with 8 maxillary sinuses grafted with Bio-Oss added to autogenous bone graft (BO + AB) 1:1. Results In group AB, 37.8% of bone was formed in the pristine bone region, 38.1% in the intermediate and 44.5% in the apical region. In group BG, 43.6% was formed in the pristine bone, 37% in the intermediate and 49.3% in the apical region. In group BG + AB 1:1, 39.0% was formed in the pristine bone region, 34.8% in the intermediate and 36.8% in apical region. In group BO, 33.4% was formed in the pristine bone, 32.5% in the intermediate and 34.3% in the apical region. In group BO + AB 1:1, 32.8% was formed in the pristine bone, 36.1% in intermediate and 27.8% in the apical regions. The immunolabeling for osteocalcin showed an intensive staining for all groups, which could demonstrate the calcification of the bone formed. Conclusion This study showed that the groups evaluated formed a suitable lamellar bone in the maxillary sinus reconstruction after six months of bone healing, thus being indicated to receive dental implants.

Bioactive glass added to autogenous bone graft in maxillary sinus augmentation: a prospective histomorphometric, immunohistochemical, and bone graft resorption assessment

Abstract Objective The aim of this study was to compare the bone resorption rate, histomorphometry and immunohistochemical findings of bioactive glass (Biogran; Biomet, Warsaw, IN, USA) mixed with autogenous bone grafts (1:1) and autogenous bone graft isolate in maxillary sinus elevation surgery. Material and Methods A total of 9 maxillary sinuses were grafted with Biogran with autogenous bone graft (group 1) and 12 were mixed with autogenous bone graft (group 2). Postoperative cone beam computed tomography (CBCT) was used to measure the initial graft volume after 15 days (T1), and 6 months later, another CBCT scan was performed to evaluate the final graft volume (T2) and determine the graft resorption rate. The resorption outcomes were 37.9%±18.9% in group 1 and 45.7%±18.5% in group 2 (P=0.82). After 6 months, biopsies were obtained concurrent with the placement of dental implants; these implants were subjected to histomorphometric analysis and immunohistochemical analysis for tartrate-resistant acid phosphatase (TRAP). Results The average bone formation in group 1 was 36.6%±12.9 in the pristine bone region, 33.2%±13.3 in the intermediate region, and 45.8%±13.8 in the apical region; in group 2, the values were 34.4%±14.4, 35.0%±13.9, and 42.0%±16.6 of new bone formation in the pristine bone, intermediate, and apical regions, respectively. Immunostaining for TRAP showed poor clastic activity in both groups, which can indicate that those were in the remodeling phase. Conclusions The similarity between the groups in the formation and maintenance of the graft volume after 6 months suggests that the bioactive glass mixed with autogenous bone (1:1) can be used safely as a bone substitute for the maxillary sinus lift.

Estudo comparativo do vidro bioativo e osso autógeno em aumento do assoalho de seios maxilares de humanos / Comparative study of bioactive glass and autogenous bone graft in human maxillary sinus augmentation

A deficiência óssea vertical do seio maxilar impossibilita a instalação de implantes dentais necessários para a reabilitação protética contudo, técnicas cirúrgicas para a elevação da membrana sinusal e o uso dos biomateriais para enxertia óssea permitiram alterar esta condição. O ósseo autógeno é considerado o mais previsível e o padrão ouro para tal finalidade porém, biomateriais como o vidro bioativo, amplamente utilizado na odontologia, permitem substituí-lo. O objetivo deste estudo foi avaliar formação óssea, o comportamento celular e a taxa de reabsorção do vidro bioativo em 2 proporções: puro (grupo 1); adicionado ao osso autógeno 1:1 (grupo 2), comparando com o osso autógeno (grupo 3) em seios maxilares de humanos. Com 15 dias de operados os pacientes realizaram um tomografia computadorizada (TC) cone beam para determinar o volume inicial do enxerto (T1). Após 6 meses uma nova TC foi realizada determinando o volume ósseo final (T2) e também, a coleta das biópsias com a instalação simultânea de implantes dentais. As amostras foram divididas em 3 áreas: leito, intermediária e apical onde foram avaliadas a histomorfometria e imunomarcações para Runx2, VEGF, osteocalcina e TRAP. No grupo 1 os resultados foram de 42.6%, 44.5% e 48% de formação óssea no leito, intermediária e apical respectivamente. No grupo 2 as taxas encontradas foram de 36.6% no leito, 33.2% na intermediária e 45.8% na apical. No grupo 3 foi de 34.4% para o leito, 35.0 na intermediária e 42.0% na apical. (p>0.05) Os 3 grupos apresentaram-se com comportamento semelhante nas imunomarcações realizadas mostrando estar maturado e calcificado o suficiente para receber implantes dentais. As taxas de reabsorção também mostraram-se semelhantes com 44.2% para o grupo 1, 37.9% para o grupo 2 e 45.7% no grupo 3. (p>0.05) Assim, podemos concluir que o vidro bioativo possui resultados equiparados ao osso autógeno(AU)

Vertical bone deficit due maxillary sinus pneumatization forbid the dental implants placement required for prosthetic rehabilitation however, surgical techniques to elevate maxillary sinus membrane and studies about biomaterials, allows repair these situation. Autogenous bone graft is considered the most predictable and the gold standard for this nevertheless, biomaterials as bioactive glass, has been widely used in dental surgery and allows substitute it. The aim of this study was evaluate the bone formation, the cellular behavior and the resorption rates of bioactive glass in 2 proportions: pure (group 1); add to autogenous bone graft (group 3), comparing then with autogenous bone graft in human maxillary sinus. Post-operative cone beam computed tomography (CT) was used to measure the initial graft volume after 15 days (T1). Six months later, another CT was performed to evaluate the final graft volume (T2) and determine the graft resorption rate and the harvest of biopsies with dental implants placement simultaneously. The samples were divided in 3 areas: bed, intermediately and apical which were evaluated to histomorphometric and immunostaining to Runx2, VEGF, osteocalcin and TRAP. In group 1 the bone formation were 42.6%, 44.5 and 48.0% for bed, intermediately and apical respectively. In group 2 the rates were 36.6% in bed, 33.2% in intermediately and 45.8% in apical. In group 3 were 34.4% in bed, 35.0% in intermediately and 42.0% in apical. (p>0.05) the 3 groups had the same behavior for the 4 proteins showing be matured and calcified to receive dental implants. The resorption rates were similar for the 3 groups with 44.2% % for group 1, 37.9% for group 2 and 45.7% for group 3. (p>0.05) In conclusion, the bioactive glass is a good substitute to autogenous bone graft in both proportions evaluated(AU)

Análise tomográfica, histológica, histométrica e imunoistoquímica do beta tricálcio fosfato com osso autógeno em aumento do soalho de seio maxilar / The tomographic, histological, histometric and immunohistochemistry analysis of beta tricalcium phosphate mixed with autogenous bone graft in maxillary sinus floor augmentation

A proposta deste estudo é avaliar o comportamento do enxerto ósseo composto de beta tricálcio fosfato (B-TCP) misturado ao osso autógeno na proporção de 1:1 frente a reabsorção, neoformação óssea e atividade molecular na enxertia do seio maxilar de humanos. Nove seios maxilares foram enxertados com esse material (Grupo Teste) e 12 com osso autógeno (Grupo Controle). Após 7 a 15 dias, os pacientes foram submetidos a uma tomografia computadorizada (TC) cone bean para mensurar o volume inicial do enxerto (T1). Decorrido 6 meses de reparação óssea, uma nova TC foi realizada para avaliar o volume final (T2) e verificar as alterações volumétricas dos materiais. Após 6 meses, no momento da instalação dos implantes dentais, biópsias foram colhidas por meio de uma broca trefina para avaliação histomorfométrica e imunoistoquímica. As taxas de reabsorção encontradas não foram significantes (p=0.17) com médias em torno de 38.3% ± 16.6 para o grupo teste e 45.7% ± 18.6 no grupo controle. Houve significância estatística na taxa de neoformação óssea do grupo teste (25.4% ± 6.4) em comparação com o grupo controle (38.6% ± 10.5). A análise imunoistoquímica teve como objetivo avaliar as proteínas Runx2, VEGF, TRAP e Osteocalcina. Os resultados encontrados com a imunomarcação destas, mostram que este enxerto possui um alto turnover celular e um tecido conjuntivo apresentando células em um curso de diferenciação celular. Visto isso, o enxerto do B-TCP misturado ao osso autógeno 1:1 em seio maxilar apresenta características moleculares com capacidade osteogênica promissora...

The aim of this study is to evaluate the behavior of beta tricalcium phosphate (B-TCP) mixed with autogenous bone compost graft in the rate 1:1 analyzing bone reabsorption, bone formation and molecular activity in grafting human maxillary sinus floor augmentation. Nine maxillary sinus were grafted with this material (Test group) and 12 with autogenous bone graft alone (Control Group). After 7 – 15 days, patients were submitted to an initial computed tomography (CT) to measure the initial graft volume (T1). After 6 months of bone healing, new CT was performed by patients to evaluate bone graft final volume (T2) and the graft volumetric changes. During dental implants placement, biopsies were collected with a 3.0 mm trephine burr and processed to histomorphometric and immunohistochemistry analisys. The average of reabsorption rates of test group were 38.3% ± 16.6 and 45.7% ± 18.6 to control group (p=0.17). The new bone formation was statistical significant between test group (25.4% ± 6.4) and control group (38.6% ± 10.5) (p<0.05). The immunohistochemistry analysis evaluated Runx2, VEGF, TRAP and Osteocalcin proteins. Outcomes showed a high cellular turnover with a pathway cellular differentiation in connective tissue. Thus, B-TCP mixed with autogenous bone graft in maxillary sinus presents propitious molecular characteristics to osteogenic capacity...

O uso do beta-tricálcio fosfato como substituto ósseo em odontologia / Beta-tricalcium phosphate as a bone graft substitute in dentistry: a literature review

A correção de defeitos ósseos consiste na restauração das estruturas perdidas, podendo ser substituídos por implantes aloplásticos ou enxertia de ossos. Devido às conhecidas desvantagens da remoção dos enxertos autógenos, grande parte das pesquisas em Odontologia busca desenvolver materiais, aloplásticos ou não, capazes de substituir osso suplantando essas limitações. O beta-tricálcio fosfato (β-TCP) é um substituto ósseo sintético, biocompatível, osteocondutor, disponível em forma de grânulos que pode ser utilizado em reconstruções alveolares. Neste trabalho, buscamos realizar uma revisão da literatura sobre as características do β-TCP e discorrer sobre sua aplicação na Odontologia.

The correction of bone defects is the restoration of lost structures which can be replaced by alloplastic implants or bone grafts. Due to the known disadvantages of removal of autogenous grafts, most researches in dentistry aim to develop alloplastic or non-alloplastic materials able to replace bone without these limitations. Beta-Tricalcium Phosphate (β-TCP) is a synthetic granular bone substitute, biocompatible, osteoconductive, which can be used in the alveolar reconstruction. In this work, we perform a literature review on the β-TCP characteristics and discuss its application in dentistry.