Primary and Secondary Stability of Nano-Hydroxyapatite-Coated vs. Sandblasted, Acid-Etched Tapered Implants in the Posterior Maxilla: A Randomized Controlled Trial

Background: There is a dearth of clinical studies comparing the primary and secondary stability (SS) of nano-hydroxyapatite-coated, sand-blasted, and acid-etched (SAE) implants placed in the posterior maxilla. Objective: The null hypothesis is that there is no difference in the primary and secondary outcomes of nano-hydroxyapatite-coated and SAE implants placed in the posterior maxilla. The aim was to assess the primary and secondary outcomes of nano-hydroxyapatite-coated and SAE tapered implants placed in the posterior maxilla. Methods: The study employed a triple-blinded randomized controlled trial design. Information regarding the patients’ age, gender, and the duration of edentulism in the maxillary molar region was collected using a structured questionnaire. Participants were randomly divided into two groups: Group 1–Individuals who received nano-hydroxyapatite-coated implants (n=26); and Group 2–Individuals who received SAE implants (n=26). The primary stability (PS) was measured immediately after implant placement, and SS was assessed at four and six weeks and four months of follow-up. Group comparisons were performed, and the level of significance was set at P<0.05. Results: At four (P<0.01) and six weeks (P<0.01) of follow-up, SS was significantly higher in Group-1 than in Group-2. There was no difference in SS at four months of follow-up in groups 1 and 2. There was no statistically significant correlation between implant stability and age, gender, implant dimensions, or insertion torque. Conclusion: Due to the stringent inclusion criteria and the use of a convenience sampling design, it is challenging to draw definitive conclusions about the effects of nano-hydroxyapatite-coated versus SAE implants on primary SS in the posterior maxilla.