Crestal bone loss associated with different implant surfaces in the posterior mandible in patients with a history of periodontitis. A retrospective study.

OBJECTIVE

To retrospectively assess the interproximal bone loss (CBL) in external hexagon implants (EHI), with different surface micro-topography, placed in the posterior mandible in patients with a history of periodontitis undergoing supportive periodontal care.

MATERIAL AND

METHODS

268 consecutive patients received 755 EHI implants in the mandibular molar region between 2007 and 2015 with the following surface characteristics: 72 turned, 145 hybrids (double acid-etched/turned), and 538 anodized. CBL was yearly evaluated by analysing calibrated digital periapical radiographs, with a follow-up of 1-6 years. Data on implant survival were also calculated.

RESULTS

At 6 years (53 patients), the mean CBL was 1.34/1.42 mm at patient/implant level, respectively (range: 0-5.2 mm). Significantly higher CBL was detected in anodized implants than in turned and hybrid implants (1.92/1.46/1.02 mm) (p < .01). The maximum CBL values were found in 2 anodized implants at 4 years (6.3 and 8.1 mm). CBL ≥2 mm was detected in 18% of implants at 3 years and 35% at 6 (p < 2.2 × 10-16 ), this prevalence being 2.6 times higher in the anodized than in the hybrid and turned group (40%/15.6%, p < .0094). At 6 years, 25 anodized implants presented CBL ≥3 mm (18%). 6 anodized implants (5 patients) were removed between 4 and 5 years.

CONCLUSION

A significant higher CBL was observed in anodized, compared to hybrid and turned implants, when placed in the mandibular molar region of periodontal patients, with a follow-up of 1 to 6 years.