Impacto de overdentures mandibulares retidas por 2 e 3 implantes na remodelação óssea dos maxilares e peri-implantar, 3 anos de acompanhamento

Abstract

This study evaluated the impact of mandibular overdentures retained by 2 and 3 implants on bone remodeling of the jaws and on the peri -implant bone level, by radiographic analysis, in users of Maxillary Total Dentures (MTD) and Mandibular Overdentures (OM), after 3 years in function. The sample consisted of 2 groups: i) OM retained by 2 implants (OM2, n=12) ii ) OM retained by 3 implants (OM3, n=12). Digital panoramic radiographs taken at the OM installation (T0) and after 1 year (T1) and after 3 years (T2) were measured linearly to evaluate the anterior and posterior bone area and height of the maxilla and mandible and the periimplant bone level. Reference points and lines were drawn using 2 software programs, Adobe Photoshop CS6 and Image J. For statistical analysis, the data were subjected to the Shapiro-Wilk normality test, ANOVA test for comparison between groups and paired t-test for intra-groups with a significance level adopted of 5%. During the first year, the OM2 group presented slight bone resorption (-0.07 ± 0.18 mm; p = 0.03) in the anterior maxillary area in contrast to the posterior maxillary and mandibular areas that did not present differences and remained stable. The posterior area of the maxilla presented a significant difference with slight bone apposition in the OM2 group (0.07 ± 0.19 mm; p = 0.008) and a slight bone loss in the OM3 group (-0.03 ± 0.19 mm; p = 0.001), at this evaluation time. After 3 years of use, the OM3 group presented a discrete bone resorption (-0.05 ±0.13 mm; p=0.02) in the anterior maxillary area, while for OM2, stable values were observed in the posterior maxillary area (0.00±0.19 mm; p=0.02). Considering the comparisons between groups in the evaluation times, the left mandibular linear height L3 presented a significant difference in the third year (OM2=-2.23±2.9 mm; OM3=0.52±2.9 mm; p=0.03). In the peri- implant bone level of the groups, in the first year, for the OM2 group, bone loss was noted in the peri- implant bone level of the mesial face of the right implant (-0.24±0.34 mm; p=0.02), as well as for the OM3 group, which presented bone loss in the right face of the median implant (-0.28±0.36 mm; p=0.01). After 3 years of use, in the OM2 group, loss of the peri -implant bone level was found in the mesial face of the right implant (-0.31±0.43 mm; p=0.02) and in both faces of the left implant (mesial =-0.28±0.31 mm; p=0.007); (distal=-0.27±0.43 mm; p=0.04). In the OM3 group, differences were found on the right side of the median implant (- 0.37±0.31mm; p=0.001) and on both sides of the left implant (mesial0.32±0.41mm; p=0.02); (distal -0.32±0.42mm; p=0.02), indicating loss of periimplant bone level in 3 of the 6 sides evaluated. Conclusion: The treatment of totally edentulous patients with OM retained by 2 and 3 implants presented stable bone remodeling in the maxilla and mandible after 3 years in function