Avaliação da estabilidade de implantes dentários em intervalos precoces após a implantação in vivo: estudo experimental em cães

Abstract

It is generally accepted that even though dental implants may be mechanically stable during and immediately after placement, interfacial remodeling will decrease its stability before it is reestablished through osseointegration. This study aimed to demostrate the degree of dental implants stability decrease and subsequent increase at early implantation times in a beagle model. The lower premolars and first molar of 8 beagle dogs were extracted and the ridges allowed healing for 8 weeks. Thirty-two (n=16 each group) implants were bilaterally placed, remaining for 1 and 3 weeks in vivo. The implants with comparable dimensions groups were as follows: Group 1- Straumann Bone Level with SLActive surface (Straumann, Switzerland); Group 2- Nobel Speedy Replace RP with TiUnite surface (Nobel Biocare, Sweden). During insertion and following euthanasia, the implants were torqued to determine insertion and interface failure values. Histologic sections were prepared for microscopy. Statistical analysis was performed Kruskall-Wallis at 95% level of significance and Dunn s post hoc test for multiple comparisons. High insertion torque values were observed along with a significant decrease at 1 week in vivo (p=0.003). At 3 weeks the biomechanical fixation levels increased and were comparable to the insertion torque value. Histology showed that interfacial bone remodeling and initial woven bone formation was observed around both implant groups at 1 and 3 weeks. In conclusion, as time elapsed early after implantation, the biomechanical stability of dental implants initially decreased and subsequently increased.