Bone autografts & allografts placed simultaneously with dental implants in rabbits.

OBJECTIVE: This study compared stability, removal torque, bone implant contact (BIC) and area (BA) of implants installed simultaneously with onlay autografts or allografts in rabbits' tibias. MATERIAL AND METHODS: Total of 18 rabbits were used in this study. Fresh frozen allografts were obtained from six animals at T(-6). Two implants with autogenous grafts (Group 1) or allografts (Group 2) were simultaneously inserted into both sides of the tibiae in a vertical periimplant defect model at T0. The resonance frequency (ISQ) was measured in implant proximal epiphysis on the day of installation of T0 and T18 (18 weeks post-surgery). At T18 the removal torque was assessed at the distal implants, the implants' proximal epiphysis and surrounding bone were harvested to perform histomorphometric analysis. The BIC and BA within the limits of the implants threads were evaluated. RESULTS: The ISQ revealed a statistically significant difference between T0 and T18 in each group (p = 0.024, p = 0.003). The removal torque indicates that there was no significant difference between the two groups (p = 0.47). No significant differences were observed between the groups regarding both BIC (p = 0.3713) and the BA (p = 0.3883). CONCLUSION: Both grafts and implants demonstrated the same stability, torque removal and the BIC and BA.

Stability of implants placed simultaneously or in a delayed manner on fresh frozen onlay allografts in rabbits.

OBJECTIVES: This study evaluated the stability of implants installed simultaneously and in a delayed manner in fresh frozen onlay allografts in the tibiae of rabbits. MATERIAL AND METHODS: Analyses of the resonance frequency (ISQ) and removal torque were performed. The calvarium of three rabbits was used as donor site. Ten New Zealand female rabbits received four allografts of the same dimensions, two in each tibia. The tibiae were randomly allocated into the following two groups: Group 1, the tibiae that received implants after 84 days of healing, and Group 2, those who received the implants simultaneously with the grafts. Both groups were followed for 126 days. Proximal implants in each group were evaluated by resonance frequency (ISQ) on days 0 and 126, and the distal ones with removal torque on day 126. RESULTS: In both groups, an increase in the ISQ value of day 0-126 was observed, with a statistically significant difference (Group 1 P = 0.049 and Group 2 P = 0.021). When comparing the resonance frequency at day 0 to day 126, and the gain of stability between these days, no statistically significant difference between groups could be observed. The removal torque showed a statistically significant difference between groups 1 and 2 (P = 0.042). CONCLUSION: There was an increase in stability in groups according to the analysis of resonance frequency. Implants installed in a delayed manner in allografts showed higher shear force, according to the removal torque analysis.

Utilização de enxerto alógeno na odontologia: relato de caso clínico / Bone allografts in implant dentistry

As perdas ósseas nos arcos maxilares têm sido motivo de grande preocupação na Implantodontia por limitar a instalação de fixações. As técnicas de reconstrução óssea possibilitaram a ampliação das indicações para a instalação de implantes osseointegrados em locais anteriormente inacessíveis. O enxerto autógeno intrabucal é o procedimento mais utilizado na correção de defeitos de rebordo. Nas regiões onde a quantidade e o custo são fatores limitantes ao tratamento com os enxertos autógenos convencionais, surgem novas possibilidades como o uso dos aloenxertos. Protocolos de captação e estocagem realizados pelos bancos de ossos permitem uma maior segurança no uso dos aloenxertos. O objetivo deste estudo é relatar um caso clínico de reconstrução com aloenxerto em uma paciente que possuía um defeito ósseo decorrente de processo infeccioso dental em maxila. Desta forma, pode-se demonstrar que os enxertos ósseos alógenos podem ser utilizados nas reabilitações dos maxilares como alternativa aos enxertos autógenos.

The lack of bone tissue limits the insertion of osseointegrated fixtures and is motive of concern in Implant Dentistry. The techniques of bone reconstruction allowed the expansion of indications for the installation of anchorages in places previously impractical. The grafting autogenous intra-oral is the rnost commonly used in tissue reconstruction to rehabilitation with implants. In areas where the quantity and cost are limiting factors to treatment with conventional autografts, there are new possibilities as the use of allografts. The development of tissue banking improves the methods of processing and storage, increasing the quality and safety of banked bone. The aim of this study was to report a case of reconstruction with allograft in one patient who had abone defect caused by dental infection process in the jaw. Thus, one can demonstrate that the allograft may be used in the rehabilitation of the jaws as an alternative to autografts.