The effect of implant design on insertion torque and immediate micromotion

Objectives: To evaluate the effect of insertion torque on micromotion to a lateral force in three different implant designs. Material and methods: Thirty-six implants with identical thread design, but different cutting groove design were divided in three groups: (1) non-fluted (no cutting groove, solid screw-form); (2) fluted (901 cut at the apex, tap design); and (3) Blossomt (Patent pending) (non-fluted with engineered trimmed thread design). The implants were screwed into polyurethane foam blocks and the insertion torque was recorded after each turn of 901 by a digital torque gauge. Controlled lateral loads of 10N followed by increments of 5 up to 100N were sequentially applied by a digital force gauge on a titanium abutment. Statistical comparison was performed with two-way mixed model ANOVA that evaluated implant design group, linear effects of turns and displacement loads, and their interaction. Results: While insertion torque increased as a function of number of turns for each design, the slope and final values increased (Po0.001) progressively from the Blossomt to the fluted to the non-fluted design (M +/- standard deviation [SD] = 64.1 +/- 26.8, 139.4 +/- 17.2, and 205.23 +/- 24.3 Ncm, respectively). While a linear relationship between horizontal displacement and lateral force was observed for each design, the slope and maximal displacement increased (Po0.001) progressively from the Blossomt to the fluted to the non-fluted design (M +/- SD 530 +/- 57.7, 585.9 +/- 82.4, and 782.33 +/- 269.4 mm, respectively). There was negligible to moderate levels of association between insertion torque and lateral displacement in the Blossomt, fluted and non-fluted design groups, respectively. Conclusion: Insertion torque was reduced in implant macrodesigns that incorporated cutting edges, and lesser insertion torque was generally associated with decreased micromovement. However, insertion torque and micromotion were unrelated within implant designs, particularly for those designs showing the least insertion torque.

Rehabilitation of the Maxillary Arch After Bone Graft Using Immediate Loading With Implant-Supported Fixed Restoration

Moderate and controlled loading environments support or enhance osteogenesis, and, consequently, a high degree of bone-to-implant contact can be acquired. This is because when osteoprogenitor cells are exposed to limited physical deformation, their differentiation into osteoblasts is enhanced. Then, some range of microstrain is considered advantageous for bone ingrowth and osseointegration. The primary stability has been considered one of the main clinical means of controlling micromotion between the implant and the forming interfacial tissue, which helps to establish the proper mechanical environment for osteogenesis. Based on the biological aspects of immediate loading (IL), the objective of this study is to present a clinical case of maxillary arch rehabilitation using immediate loading with implant-supported fixed restoration after bone graft. Ten dental implants were placed in the maxilla 6 months after the autogenous bone graft, removed from the mandible (bilateral oblique line and chin), followed by the installation of an immediate-load fixed cross-arch implant-supported restoration because primary stability was reached for 8 implants. In addition, instructions about masticatory function and how it is related to interfacial micromotion were addressed and emphasized to the patient. The reasons for the IL were further avoidance of an interim healing phase, a potential reduction in the number of clinical interventions for the patient, and aesthetic reasons. After monitoring the rehabilitation for 8 years, the authors can conclude that maxillary IL can be performed followed by a well-established treatment planning based on computed tomography, providing immediate esthetics and function to the patient even when autogenous bone graft was previously performed in the maxilla.