ABSTRACT
Objetivo: Estudos demostraram que a zircônia monolítica um dos materiais restauradores desenvolvidos recentemente, resolveu vários problemas de restauração de zircônia. Portanto, a precisão marginal e o ajuste interno são necessários para o sucesso clinico e para a qualidade da restauração, e o espaço do cimento pode influenciar o ajuste marginal. Assim, o presente estudo teve como objetivo investigar os efeitos da espessura do cimento e o tipo de restauração na discrepância marginal. Material e métodos: foram usadas para fabricação de coroa total. Dois tipos de materiais incluindo Zirconia monolítica (Zolid) e Sintron foram usadas para produzir a coroa total. As amostras de cada grupo foram digitalizadas em laboratório dentário por um scanner 3D, projetadas e acessadas usando CAD-CAM. As amostras foram divididas em quatro grupos de cinco com espaço de 30 e 50 mícrons de cimento. Para avaliar a discrepância marginal, as coroas foram colocadas em seus respectivos dentes sem o uso de qualquer intermediário e examinados em micro-CT. Os dados foram avaliados pelo software SPSS. Resultados: Descobriu-se que a discrepância marginal do Sintron é maior que a discrepância da zircônia monolítica. Na verdade, a zircônia monolítica com espaço de 50 µm de cimento exibiu uma menor discrepância marginal, e o espaço de cimento do Sintron não influenciou significantemente na discrepância marginal. Conclusão: Concluiu-se que os tipos de material e o espaço do cimento influencia na discrepância marginal da restauração construída pelo fluxo digital (AU)
Objective: Studies demonstrated that as one of then ewly developed restorative materials, monolithic zirconia resolved several issues of zirconia restoration. Therefore, marginal accuracy and internal fit are necessary for clinical success and quality of restorations, and cement space may influence the marginal fit. Thus, the present research aimed to investigate the effects of the cement thickness and kind of restoration on the marginal discrepancy. Material and methods: In this study, 20 maxillary left first molars, prepared by DRSK Co., were used to fabricate a full crown. Two types of material included monolithic zirconia (Zolid) and Sintron were used to make a full crown. Samples from each group were scanned by dental laboratory 3D scanner and designed and processed using CAD-CAM. The samples were divided into four groups of five with 30-and 50- µm cement spaces. In order to assess the vertical marginal discrepancy, the crowns were fittedon their respective teeth without using any mediator and examined by a micro-CT scanner. Data were analyzed by SPSS software. Results: It has been found that marginal discrepancy in Sintron is higher than the discrepancy of monolithic zirconia. In fact, monolithic zirconia with 50-micron cement space exhibited the least marginal discrepancy and the cement space in Sintron did not significantly influence the marginal discrepancy. Conclusion: It has been concluded that the material kinds and cement space influence the restoration marginal discrepancy constructed by digital workflow (AU)
Subject(s)
Dental Marginal Adaptation , Dental Cements , X-Ray MicrotomographyABSTRACT
Abstract Objective: To evaluate the prevalence of temporomandibular disorders (TMDs) for those patients with dentofacial deformities, who underwent orthognathic surgery, and the control group. It also identified whether orthognathic surgery had a positive or negative impact on TMD symptoms by comparing TMD patients, who underwent orthognathic surgery, and people did not experience this surgery. Finally, this systematic review and meta-analysis aimed to evaluate the effectiveness of orthognathic surgery on the pre-existing TMDs in malocclusion patients. Material and Methods: MEDLINE, PubMed, Cochrane Library, Embase, ISI, google scholar have been utilized as the electronic databases for systematically reviewing the literature between 2001 and February 2019. Inclusion criteria were undergoing orthognathic surgery, patients with/without pre-existing TMDs, and physical disabilities. Results: A total of 669 abstracts and titles with potential relevance have been identified in the course of the manual and electronic searches. It has been found that five studies met our inclusion criteria for a systematic review. Temporomandibular disorders (TMDs) before orthognathic surgery in comparison to the controls (RR=0.02; 95% CI -0.08-0.13) and heterogeneity among the papers has been I2 = 42.86% (p=0.64). Conclusion: Malocclusion by orthognathic and orthodontics surgeries had a considerable rate of TMD compared to the controls.