Periodontal response to subgingival restorations in dogs with periodontitis

The aim of this study was to evaluate the periodontal response to subgingival restorations in dogs with naturally occurring periodontitis. At the baseline, the experimental teeth from three dogs (2nd and 3rd upper premolars and 2nd, 3rd and 4th lower premolars) were randomly assigned to Resin-modified Glass Ionomer Cement (RMGIC) and Amalgam (AM) restorations or controls (CT) at the buccal sites with (SUPRA+) or without mechanical supragingival plaque control (SUPRA-) and maintained for 90 days. Clinical [Periodontal Probing Depth (PPD), Clinical Attachment Loss (CAL), and Gingival Margin Recession (GMR)], histological (connective tissue inflammatory and epithelium condition) and histometric evaluation (distance between the apical border of the cavity and the bone level and between the apical extension of the epithelium and the bone level) were performed by a calibrated blinded examiner. Better clinical (especially regarding CAL) and histological results (unaltered epithelium and less severe inflammatory connective tissue) were observed associated with RMGIC sites. Histometric evaluation showed less bone loss associated to RMGIC. Overall, SUPRA+ sites presented less inflammatory response. It could be concluded that in dogs with periodontitis, subgingival RMGIC restorations, especially in the presence of supragingival plaque control, elicited better periodontal response than AM restorations.

O objetivo do presente estudo foi avaliar a resposta do periodonto a restaurações subgengivais em cães com diagnóstico de periodontite. No início do estudo, os dentes experimentais de três cães (2o e 3o molares superiores e 2o, 3o e 4o premolares inferiores) foram randomicamente designados para restauração com cimento de ionômero de vidro modificado por resina (CIVMR), amálgama (AM) ou Controle (CT) nos sítios vestibulares submetidos (SUPRA+) ou não (SUPRA-) a controle mecânico de placa supragengival e mantidos por 90 dias. Avaliações clínicas [Profundidade de Sondagem (PS), Nível de Inserção Clínica (NIC), Recessão Gengival (RG)], histológicas (condições inflamatórias do tecido epitelial e conjuntivo) e histométricas (distância entre a margem apical da cavidade e o nível ósseo e entre a extensão apical do epitélio e o nível ósseo) foram realizadas por examinador calibrado e cego. Melhores resultados clínicos (especialmente quanto à PI) e histológicos (epitélio sem alterações e tecido conjuntivo com menor severidade de infiltrado inflamatório) foram observados em associação a sítios restaurados com CIVMR. A avaliação histométrica mostrou menor perda óssea associada a restauração com CIVMR. Todos os sítios SUPRA+ exibiram menor resposta inflamatória. Pode ser concluído que, em cães com periodontite, restaurações subgengivais realizadas com CIVMR, especialmente na presença de controle mecânico de placa supragengival, apresentaram melhor resposta do periodonto quando comparadas com restaurações de amálgama.

El área cervical de implantes dentales presenta mayor formación ósea que el área apical en diferentes condiciones de diseño y carga: resultados preliminares / The cervical area of dental implants present more osseous formation than apical area in different load and design condition: preliminary results

Los implantes dentales han evolucionado de forma sustancial en los últimos 40 años; sin embargo, dudas sobre las características de la reparación ósea continúan toda vez que nuevos diseños y nuevos métodos quirúrgicos son aplicados. El objetivo de esta investigación es evidenciar la presencia de tejido mineralizado en diferentes regiones del implante. Se elaboró un estudio basado en un modelo de restauración inmediata, aplicado en la mandíbula de 7 canes machos. Se realizaron las exodontias de los premolares mandibulares y, después de 3 meses de recuperación, se instalaron 2 implantes endóseos bilaterales, siendo uno de tipo cónico y otro de tipo cilíndrico. Después de dos periodos de sacrificio se realizo una evaluación histomorfométrica en los cortes seleccionados. Los resultados se presentan de forma porcentual estableciendo comparaciones entre las áreas cervical, media y apical. Los implantes de morfología cónica sometidos al modelo de restauración inmediata, presentaron mayor formación ósea en todos los niveles evaluados. En todas las condiciones de trabajo el área cervical presentó mayor presencia de tejido mineralizado que el área apical. Concluimos que el modelo de restauración inmediata no es un obstáculo para la instalación de la secuencia apropiada de reparación ósea y que diferentes factores deben estar asociados a la mayor formación ósea presente en el área cervical de los implantes dentales.

Dental implants have evolved of substantial form in the last 40 years; however, doubt about osseous repair characteristic are maintained because new design and surgical method are applied. The aim of this research is show the mineralized tissue in different areas of the implant. Was done a study based to a immediate load model applied in 7 male dogs mandible. Was realized the dental extractions of de bilateral mandibles bicusp and after to 3 month of recuperations was installed two bilaterally implants, been conical and cylindered shape. After of two sacrifices period was realized a histomorphometric analysis in the selection cut. The results are present with perceptual form, establishing cervical, meddle and apical comparison. Conical implants with immediate restoration model were present more osseous formations in all evaluated level. For all conditions of work, cervical area presented more mineralized tissue than apical area. We conclude that immediately restoration model it is not an obstacle for the installation of the appropriate sequence for the osseous reparation and that different factors have been associated to the more osseous formation in the cervical area of the dental implants.