Thermal oxidation and hydrofluoric acid treatment on the sandblasted implant surface: A histologic histomorphometric and biomechanical study.

OBJECTIVES: This study aimed to analyze and compare the topographical, chemical, and osseointegration characteristics of a sandblasted acid-etched surface (SLA group), a sandblasted thermally oxidized surface (SO group), and a surface chemically modified by hydrofluoric (HF) acid (SOF group). MATERIALS AND METHODS: Following the preparation and characterization of the relevant surfaces, 90 implants (30 for each group) were placed on the pelvic bone of six sheep. Resonance frequency analysis (RFA), insertion (ITV), removal torque value (RTV), and histomorphometric analyses (BIC%) were performed after three and 8 weeks of healing. The results were analyzed by nonparametric tests (p < 0.05). RESULTS: The roughness value (Ra) in the SOF group was significantly lower than the SLA and the SO group (p = 0.136, p < 0.001, respectively). This resulted in a substantially inferior ITV 14.83 N/cm (SD: 4.04) than those achieved in the SLA and SO groups (19.50 (SD: 6.07) and 20.17 N/cm (SD: 8.95), respectively; p = 0.001). A statistically significant change in the RFA from the baseline (47.36 ISQ, SD: 6.93) to the 3rd week (62.56 ISQ, SD: 5.29) was observed in the SOF group only (p = 0.008). The highest postplacement RFA and RTV values were measured from the SLA group (61.11 ISQ, SD: 7.51 and 78.22 N/cm, SD: 28.73). The early-term (3rd week) BIC% was highest in the SO group (39.93%, SD: 16.14). After 8 weeks, the differences in BIC% values were statistically not significant. CONCLUSIONS: Adjunct HF acid application on the thermally oxidized surface did not provide an additional benefit compared to the sandblasted and acid-etched surface (SLA group).