The scope of this study is to assess the influence of different interimplant distances on prosthetic complications in two implant mandibular overdenture treatments, as well as the possible correlations between such complications and some anatomic and functional individual aspect of the patients. Materials and method. An observational clinical study was conducted between October 2008 – March 2010 – in the Clinics of Dental Prosthetics of the Carol Davila UMF of Bucuresti – on 32 completely edentulous patients, treated with 2 implant mandibular overdentures. The patients (24 women and 8 men, with ages between 49 and 83 years) were divided into 2 groups, according to the position of the implants, inserted at the level of the lateral incisor (group 1) or in posterior position versus the canine (group 2). The prosthetic aspects, the peri-implant tissues and the anchoring systems were evaluated after 6 months and, respectively, 1 year of treatment, all prosthetic or biological complications, as well as the number of visits necessary for solving them being recorded. Results. As to the general characteristics of the group of patients, the observation was made that the average age of patients was of 63.8 years, most of them evidenced a severe resorbtion of the crest, oval in shape in the mandibular frontal area, belonging mostly to the IInd hypo or hyper-divergent skeletal class, proportionally with and without a tendency towards propulsion. For both groups of patients, a total number of 114 prosthetic complications were registered after one year, the most frequent ones being occlusal problems (23.68%), the presence of decubitus lesions (21.05%) and deactivation of matrices, accompanied by reduced retention (19.29%). Lower ratios were recorded for: the necessity of prosthesis relining (14%), loss of matrices (12.28%), fracturing of the prosthesis (8.77%), presence of peri-implant gingival hyperplasies (7%) and loosening of the patrix screw (5.26%). The most frequently occurring complication in the first 6 months after the treatment was, in both groups, the presence of decubitus lesions, followed by the loss of matrices and gingival hyperplasies in the first group, and deactivation of matrices, respectively, in the second. Conclusions. The present study confirms the hypothesis according to which implants position, correlated with the individual characteristics of the patients, may influence the clinical results of the prosthetic treatment, as well as the oral structures. Knowledge on the anatomical and functional characteristics of the patient, and on the biomecanical behaviour of this type of prostheses may considerably reduce the number of complications, by a correct, individualized treatment
Keywords:- implants
- individual characteristics
- inter-implant distance
- mandibular overdenture
- prosthetic complications