Abstract:The purpose of the present study was to assess the influence of local and systemic factors on the occurrence of dental implant failures up to the 2nd stage surgery (abutment connection). This retrospective study is based on 2,670 patients who received 10,096 implants and were consecutively treated with implant-supported prostheses between 1980 and 2014 at one specialist clinic. Several anatomical-, patient-, health-, and implant-related factors were collected. Descriptive statistics were used to describe the patients and implants. Univariate and multivariate logistic regression models were used at the patient-level as well as at the implant-level, to evaluate the effect of explanatory variables on the failure of implants up to abutment connection. A generalized estimating equation method was used for the implant-level analysis, to account for the fact that repeated observations (several implants) were available for a single patient. Overall, 642 implants (6.36%) failed, of which 176 implants (1.74%) in 139 patients were lost up to the 2nd stage surgery. The distribution of implants in sites of different bone quantities/qualities was quite similar between implants lost up to and after abutment connection. Smoking and the intake of antidepressants were the statistically significant predictors in the multivariate model. Trial registration at the U.S. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59
IntroductionNowadays dental implant placement is an effective and predictable treatment modality for replacing missing teeth in both fully and partially edentulous patients. Nevertheless, failures still happen despite the high implant survival and success rates (Chrcanovic et al., 2014). Failures of dental implants can be subdivided into early and late failures, depending on whether they occur before or at abutment connection surgery (early) or after occlusal loading by a prosthetic restoration (late). This subdivision is relevant as it is suggested that the failures in these two distinct time periods may be associated with different factors. An early failure of an implant results from an inability to establish an intimate bone-to-implant contact. In this case the bone healing after implant insertion is impaired and may be influenced by local and systemic factors (Alsaadi et al., 2007). Systemic diseases and compromising risky habits may affect oral tissues by increasing their susceptibility to other diseases or by interfering with wound healing. Surgical conditions, submission to radiotherapy, and the intake of medications by the patient may play a role on the outcome of implants. When it comes to late implant failures, the oral microbial environment, parafunctional habits, and the prosthetic rehabilitation variables are also taken into account. Although many studies have shown the influence of local and systemic factors in the long-te...