Marginal bone loss pattern around hydroxyapatite-coated versus commercially pure titanium implants after up to 12 years of follow-up

Purpose: The purpose of this study was to compare the marginal bone loss (MBL), complications, and 12-year survival rates of commercially pure titanium (cpTi) and hydroxyapatite (HA)-coated implants placed in the maxilla. Materials and Methods: The study group consisted of 120 patients (77 women, 43 men) treated from 1988 to 1997. A total of 388 implants (156 cpTi and 232 HA-coated) were placed in the maxilla. There were 126 immediate (32.5%) and 262 (67.5%) nonimmediate implants. Patients were evaluated annually. Mean follow-up was 60 ± 32.3 months. MBL was measured on radiographs using the implant threads as the dimensional reference. MBL, complications, and 12-year survival and success rates were correlated with implant coating, time of implantation, implant dimensions, and position in arch. Results: Total mean MBL was 1.07 ± 2.16 mm. MBL was significantly lower with cpTi implants (0.55 ± 1.04 mm) compared to HA-coated implants (1.51 ± 2.71 mm) (P < .001). No statistical difference in regard to MBL was found between immediate and nonimmediate implants (0.86 ± 1.8 mm vs 1.16 ± 2.3 mm). The total 12-year survival rate was 91.4%. HA-coated implants had a significantly higher 12-year survival rate than cpTi implants (93.2% vs 89%; P < .03). Nonimmediate implants had a significantly higher failure rate (8.2%) than the immediate implants (1.3%) (P < .009). No correlation was found between type of implant coating and late implant failure. Discussion: Immediate implants can serve as a predictable option, providing higher survival and success rates. HA-coated implants tended to fail less during the surgical phase, but had higher mean MBL compared to cpTi implants. Conclusions: HA-coated implants had greater MBL than cpTi implants but a higher 12-year survival rate. Immediate implants had a lower failure rate than the nonimmediate implants in this study population.