ABSTRACT
INTRODUCTION: One of the most common esthetic complaints among dental patients is a gingival smile, which may be of multifactorial etiology, e.g. gingival hyperplasia, skeletal deformities featuring overgrowth of the anterior maxilla, altered passive eruption, maxillary alveolar tooth extrusion, fine lip and hypermobility of lip elevator muscles, which must be diagnosed prior to treatment so that the appropriate management approach can be selected. Maxillary overgrowth may give rise to subnasal skeletal depression where the upper lip retracts to during smiling, causing gingival exposure. The objective of this case report was to describe a lip repositioning technique using polymethylmethacrylate (PMMA)-based bone cement for esthetic smile rehabilitation. CASE REPORT: A 23-year-old female attended the Esthetic Dentistry Clinic of our institute, reporting dissatisfaction with her smile, due to the size of her teeth and the amount of gingiva exposed when smiling. A rehabilitation planning was designed, which was performed with periodontal surgical intervention to fill the subnasal depression with PMMA-based bone cement. After crown lengthening, the PMMA-based bone cement was prepared with gentamicin in a sterile surgical bowl. When the mixture stopped sticking to the surgical gloves, it was then positioned into the subnasal pit, under constant and copious saline irrigation. With the cement in place, the prosthesis was shaped in a maximum thickness of 7-mm. After complete polymerization and under abundant cooling, refinement and finishing of the PMMA prosthesis was performed. The prosthesis was fixed onto the bone with two titanium-based bone graft fixation screws. The smile aesthetic rehabilitation was complemented using 10 lithium disilicate-based ceramic veneers. DISCUSSION AND CONCLUSION: PMMA-based bone cement proved effective when combined to clinical crown lengthening for esthetic smile rehabilitation, acting as a filling material for subnasal depression, providing new lip support.
ABSTRACT
O objetivo deste estudo foi avaliar as influências acarretadas pelo tratamento das superfícies das zircônias com primer apropriado na resistência de união entre cimento resinoso e uma cerâmica de Zircônia. foram utilizados 20 corpos de prova em Zircônia VIPI BLOCK ZIRCONN (VIPI, São Paulo, Brasil) divididos em 2 grupos: Grupo 1 tratamento de superfície da zircônia apenas com jateamento de óxido de alumínio e cimento resinoso PanaviaTF 2.0 (Kuraray, Kurashiki, Japão); e Grupo 2 além do jateamento usou-se o primer Ceramic Primer (3M, São Paulo, Brasil). Os espécimes cerâmicos receberam o cimento manipulado na proporção de 1:1 e foram estocados em água destilada a 37ºC por 24 horas antes e após a termociclagem. O ensaio de cisalhamento foi realizado em máquina de ensaios EMIC DL2000 (EMIC, São Paulo, Brasil), os valores de resistência de união foram apresentados em Mpa e analisados através de Análise de Variância (ANOVA) e teste t Student para amostras independentes. Os valores resistência ao cisalhamento entre cimentos e cerâmica à base de zircônia utilizando os primers mencionados não foram estatisticamente diferentes, isto é, nenhuma diferença significativa foi encontrada entre os grupos G1 (8,70 ± 6,31) e G2 (8,18 ± 3,75). Os testes realizados com o primer não mostraram aumento considerável na resistência de união ao cisalhamento entre cimentos e cerâmica à base de zircônia.
The aim of this study was to evaluate the influence of the use of primer to treat zirconia surfaces on the bond strength between resin cement and zirconia ceramics. The 20 specimens were divided into 2 groups: group 1 zirconia surface treatment with sandblasting with aluminum oxide and Panavia T f 2.0 (Kuraray); Group 2 in addition to the sandblasting Ceramic Primer (3M) was used. Each specimen of the ceramic material received manipulated cement in the proportion 1:1. The specimens were stored in distilled water at 37 ° C for 24 hours before and after thermocycling. Shear test was performed in testing EMIC DL2000 (EMIC, São Paulo, Brazil) and the values of bond strength in MPa were analyzed using Analysis of Variance (ANOVA) and Student t test for independent samples machine. There was no significant difference between the values for shear strength between both studied groups: G1 (8.70 ± 6 groups, 31) and G2 (8.18 ± 3.75). The tests performed with the primer used in this study showed no significant increase on shear bond strength between cement and ceramics based on zirconia.
