Analysis of implant loss risk factors especially in maxillary molar location: A retrospective study of 6977 implants in Chinese individuals.

ABSTRACT

BACKGROUND: The knowledge of the potential risk factors associated with implant loss is crucial for dental clinicians, but the opinions about the risk factors are still diverse and controversial. PURPOSE: This retrospective study assessed the risk factors associated with implant loss, especially that in the maxillary molar location. MATERIALS AND METHODS: From January 2015 to March 2017, 4338 Chinese patients received 6977 implants at Nanjing Stomatological Hospital. Information on patient age, gender, bone grafting procedure, implant location, length and diameter, and the records of lost implants were obtained. The Kaplan-Meier method and log-rank test were used to conduct a survival function analysis. Chi-square test and multivariate Cox regression analysis were used to identify risk factors related to implant loss. RESULTS: The cumulative survival rate (CSR) after 0-32 months of observation period for all implants was 97.76%, and the CSR for maxillary molar implants was 97.00%. Maxillary molar implants showed a significantly lower CSR than the other implants (P < .05). Male sex, short implants (<10 mm) were considered as risk factors for implant loss. However, male sex and bone grafting procedure were regarded as risk factors for maxillary molar implant loss, which was slightly different from the result of all implants. CONCLUSIONS: Male sex, short implants (<10 mm) and maxillary molar location were considered as potential risk factors for implant loss, whereas male sex and bone grafting procedure were significantly associated with implant loss in maxillary molar location.