Intramucosal inserts made of zirconia ceramic have been used for the rehabilitation of edentulous patients. This study aimed to follow up on patients with complete dentures having intramucosal zirconia inserts and to perform a histological analysis of biopsies of the epithelium surrounding the inserts. Twelve 31-66-year-old subjects of both genders received complete denture treatment having the intramucosal inserts in place. Detailed clinical, prosthetic and surgical procedures were described. Clinical exams were done on postoperative days 3, 7, 15, 120 and 360. One year after denture placement, the subjects received local anesthesia and the tissues surrounding the insertion sites in the alveolar ridge were removed using a scalpel blade. Biopsies were fixed for up to 48 h in 10% phosphate-buffered formaldehyde and 5-µm-thick sections were cut and stained with hematoxylin and eosin and Gomori Trichrome. Immunohistochemistry was used to identify endothelium (anti-CD3) and T lymphocytes (anti-CD31). Removing and reinserting the denture was painful until day 15, but all patients reported a marked increase in the retention and stability of the complete denture with little or no discomfort after 30 days. The histopathological analysis showed that zirconia inserts were well tolerated by the oral mucosa, with the presence of collagen fibers in the tissue around the insert, with mild inflammatory response and allowing reepithelialization, expressed by parakeratosis, epithelial hyperplasia and presenting granular layer. In conclusion, intramucosal zirconia inserts did not affect the health of oral mucosa and provide adequate retention and stability of the complete denture and comfort to the patients.

Esta pesquisa constatou a prevalência dos tipos de rebordos residuais no sentido ântero-posterior em extremidades livres inferiores, além de correlacionar alguns fatores que possam influenciar as suas reabsorções. Para isso, utilizamos radiografias periapicais e dados individuais colhidos na amostra de 64 hemiarcos; foram obtidas 2 radiografias de cada área de extremidade livre e, a partir de traçados, determinamos os ângulos formados pela reabsorção na altura do 1º molar inferior. Podemos constatar que: 1º) a grande maioria de inclinação encontrada foi de rebordos descendentes para distal; 2º) a média de angulação foi maior para usuários de prótese parcial removível inferior; 3º) os resultados sugeriram existir influência do tipo de arco antagônico superior na inclinação dos rebordos inferiores; 4º) observou-se aumento de inclinação quando os segundos pré-molares inferiores eram os dentes adjacentes ao espaço protético; e 5º) não foram encontradas correlações significantes entre idade, sexo e reabsorção do rebordo residual.

This study observed the prevalence of different types of residual ridge inclination in free-ends of mandibles and reported possible correlative factors that may affect resorption. For this purpose, periapical radiographs and individual data collected from a sample of 64 hemiarches were used. Two radiographs were taken of each free-end, and tracing was employed to determine the angles formed by the resorption configuration in the area of the 1st mandibular molar. The following conclusions were drawn: 1) the great majority of alveolar ridges were distally descending; 2) the average angle was wider for users of mandibular removable partial dentures; 3) the results obtained suggest that the type of opposing maxillary arch affects the inclination of mandibular ridges; 4) greater inclination was observed when the 2nd bicuspids of the mandible were the abutment teeth; 5) no significant correlation was established between age, sex and residual ridge resorption.

Esta pesquisa teve como finalidade estudar a viabilidade do preparo direto para descanso em cíngulo de incisivo central superior, por intermédio de processamento de imagem. Foram reproduzidos dez dentes íntegros, montados em um suporte de alumínio com resina acrílica e distribuídos entre cinco especialistas, que executaram os preparos para descanso. Em seguida, os corpos-de-prova foram cortados ao longo de suas coroas, tendo como guia um corte inicial, feito no centro da borda incisal de cada dente. O preparo foi então dimensionado, estabelecendo-se medidas lineares e angulares que permitissem uma análise comparativa entre o perfil original do dente e aquele após o preparo, enquanto se determinava a perfuração ou não da camada de esmalte. Todas as observações foram feitas, digitalizando-se os perfis e processando as imagens num programa específico. Dos cinqüenta modelos preparados, seguindo critérios estabelecidos, trinta e três perfuraram a camada de esmalte. Sendo assim, o incisivo central superior não está indicado para receber preparo direto para descanso de cíngulo.

The present research evaluated the viability of the direct preparation of lingual rest seats in maxillary central incisors. Ten completely sound specimens were embedded in acrylic resin supports and distributed among five specialists who prepared the rest seats. The coronary portion of the teeth was then cut using a previously made incisal index as guide. The preparation was characterized by angular and linear measurements that enabled a comparative analysis between the original outline of the tooth and its respective prepared model, while permitting the determination of dentinal exposure. The observations were undertaken in digitized images of these outlines utilizing a specific computer program. From the fifty models prepared under well-established criteria, thirty-three showed perforation of the enamel. Conclusively, the maxillary central incisor may not be indicated to receive a directly prepared lingual rest seat.