Modifying Mandibular Kennedy Class I to Class III by using Implant-Assisted Removable Partial Dentures - A 3-year clinical trial with Masticatory Performance and Quality of Life Evaluation

Abstract

The number of patients with multiple edentulism continue to grow and with the population aging trend, this number has increased. In some countries, this scenario is even worse, due to social, cultural and economic factors. Especially in the posterior region of the mandible, tooth loss leads to a change in the stomatognathic system, affecting sensory and motor aspects, affecting chewing, eating and quality of life of these patients. One of the forms of oral rehabilitation, especially in economically disadvantaged countries, is still the use of removable partial dentures. In the mandibular region, for Kennedy Class I patients, who correspond to 60% of the patients with this type of prosthesis, this treatment is associated with carious and periodontal disease of the abutment tooth, low retention of the prosthesis, pain and mucosal compression when chewing, and dissatisfaction of the patient, who often abandons the treatment. As alternative forms, dental implants appear, but often, in the case of atrophic mandibles, reconstructive bone surgeries may be necessary, increasing the possibility of complications and the complexity of the treatment, not to mention the total increase in treatment time, costs and associated morbidity. In the case of older patients, in addition to the fact that systemic diseases are present and limit these reconstructions, the patient himself may not want to choose reconstructive treatments or may not have the financial means to do so. One option may be the use of short implants to avoid reconstructions. Treatment with posterior support on a dental implant transforming the Class I patient into Kennedy Class III has already been mentioned in the literature, but when this study was started, no studies with short implants and healing had been published in the literature. Therefore, this doctoral thesis has 4 specific objectives: Specific objective 1: The objective of the present study was to evaluate the masticatory performance through the mixing ability and maximum bite force, the quality of life and the abutment tooth of the lower removable prosthesis, after the placement Neodent WS short dental implant and a screw healer and the support of the prosthesis. Specific objective 2: To review the literature critically in relation to the available masticatory performance methods, correlating them with their forms of evaluation and obtaining results, and secondarily, to evaluate if it is possible to suggest a method of masticatory performance evaluation according to the profile of the patient or the type of treatment instituted. Specific objective 3: To present a series of clinical cases of 5 consecutive patients and a quick assessment of bite force and mixing ability and satisfaction questionnaire. Our goal with this work is to propagate this type of treatment and knowledge, in addition to serving as a pilot for our first search results. Specific objective 4: In partnership with the doctoral program at USP-Ribeirão Preto, to study the performance of Neodent WS short implants for single-unit rehabilitations and to monitor the clinical and radiographic results of these implants, correlating them with the proportions of crown size and implant/prosthesis proportion. We hypothesized that they would have similar performance to implants considered standard/normal in the literature.