LAUSR

OBJECTIVE To analyze retrospectively interproximal crestal bone loss (CBL) on external-hex "non-identical" (NI) dental implants with different surface topography, when placed in the same intra-oral location in patients with a history of chronic periodontitis following maintenance care. MATERIAL AND METHODS The patient population consisted of 206 consecutive patients with a history of chronic periodontitis who underwent implant surgery between 2007 and 2010; 755 NI implants with different implant surfaces were placed at posterior mandibular sites: 72 machined, 145 acid-etched/machined (hybrid), and 538 anodized. Crestal bone loss measurements were carried out analyzing the calibrated digital X-rays taken at 1-year intervals as part of the maintenance program, being the time of this retrospective examination from 1 to 3 years. RESULTS At 3 years (51 patients), the mean CBL was 1.36/1.35 mm at implant/patient level (range: 0-6 mm). A higher CBL was observed at anodized surface implants, when compared to machined and hybrid implants, being the mean CBL 1.48, 0.96, and 0.77 mm, respectively (p = .005). CBL between 2 and 3.9 mm was found in 10.6% of the implants at 3 years (95% CI: 6%-15%), ≥4 mm in 5% (95% CI: 2%-8%). Anodized surface implants had CBL >2 mm at 2 years of 9% (95% CI: 6%-12%) and at 3 years of 18% (95% CI: 12%-24%), which were 2.5 times higher than hybrid implants with 3.6% (95% CI: 0.8%-4%) and 7.4% (95% CI: 0%-17%), respectively. CONCLUSIONS A higher CBL was observed in the anodized surface implants group, when compared to the hybrid implants group in patients with a history of chronic periodontitis followed during 1-3 years.