Fracture Resistance of Teeth Restored with Bulk-Fill and Fiber-Reinforced Composites in Class II Cavities / Resistencia a la fractura de dientes restaurados con resinas de relleno y resinas reforzadas con fibra en cavidades clase II

ABSTRACT: This study aimed to evaluate the fracture resistance of teeth restored with conventional, bulk-fill, and fiber-reinforced composite materials regarding intact teeth. Standard cavities were prepared on 70 sound third molar teeth. The teeth were randomly divided into six groups: intact teeth, conventional Bis-GMA based composite, fiber-reinforced composite, Bis-GMA based bulk-fill composite, ormocer based bulk-fill composite, glass containing resin-based bulk-fill composite. The data was obtained by a Universal Testing Machine and analyzed statistically. Fracture resistance of the teeth restored with conventional composite was significantly lower than the other groups (p0.05). The obtained data showed that restoring teeth with bulk-fill and fiber-reinforced composites could be recommended in Class II cavities.

RESUMEN: El objetivo del presente estudio fue evaluar la resistencia a la fractura de los dientes restaurados con materiales compuestos convencionales, de relleno y reforzados con fibras, en relación con los dientes intactos. Se prepararon cavidades estándar en 70 dientes de terceros molares sanos. Los dientes se dividieron al azar en seis grupos: dientes intactos, compuesto convencional basado en Bis-GMA, compuesto reforzado con fibra, compuesto de relleno a base de Bis-GMA, compuesto de relleno a base de ormocer, compuesto de relleno a base de vidrio que contiene resina. Los resultados fueron obtenidos utilizando una máquina universal de pruebas y analizados estadísticamente. La resistencia a la fractura de los dientes restaurados con el composite convencional fue significativamente menor que la de los otros grupos (p0,05). Los datos obtenidos mostraron que la restauración de dientes con composites de relleno y reforzados con fibra podría ser recomendada en cavidades de Clase II.

The stress distribution analysis of the medial-occlusal (classⅡ)cavity restored with different inlay / 实用口腔医学杂志

Objective:To analyse the stress distribution of the tooth and inlay with the restoration of resin,porcelain,gold alloy,co-balt chromium materials respectively.Methods:3-D finite element models of mandibular first molar with meiso-occlusal (class II) cavity and different inlays were established.Von-mises stress distribution on the tooth and inlay with vertical load and lingual load at 45°were analyzed.Results:After restoration peak stress of high elastic module materials and dental inlays was higher than that of the low elastic module material inlays,however,the restorations of the different elastic module materials had the similar stress distribution trend.The stress under of lateral load(lingual at 45°)to the teeth inlays was significantly higher than that under vertical load.Peak stress concentration of tooth was on the bottom of the cavity near the pulp chamber dentin;inlay peak stress distribution is mainly in its corresponding to the gingival wall.In the tooth tissues stress level of the contact surface of inlay restoration,the strength was as the fol-lowing:Composite resin inlay >ceramics inlay >the gold alloy ceramics inlay >cobalt chromium alloy inlay.The stress level of the inlay of the four kinds of inlay restoration materials was just opponent with the tooth tissues.Conclusion:Gingival wall is the weakest part of meiso-occlusal(class II)cavity inlay restoration,while near the pulp chamber at the bottom of the cavity is the weakest part of the tooth.Among the 4 materials Under the same load condition,composite resin inlay restoration has minimal tooth stress and uniform stress distribution,and can reduce the posibility of odontoschism and microleakage.

A survey on the use of composite resin in Class II restoration in Korea / 대한치과보존학회지

The purpose of this study was to assess the current materials, methods and difficulties according to the year of licence and educational background of Korean dentists in Class II direct composite resin restorations. Total 17 questions were included in the questionnaire. Questions were broadly divided into two parts; first, operator's information, and second, the materials and methods used in Class II posterior composite restoration. The questionnaire was sent to dentists enrolled in Korean Dental Association via e-mail. Total 12,193 e-mails were distributed to dentists, 2,612 e-mails were opened, and 840 mails (32.2%) were received from respondents. The data was statically analyzed by chi-square test using SPSS(v. 12.0.1, SPSS Inc, Chicago, IL, USA). Male dentists among respondents was 79%. 60.3% of the respondents acquired their licences recently (1998-2007), and 77% practiced in private offices. 83.4% have acquired their knowledge through school lectures, conferences and seminars. For the Class II restorations, gold inlays were preferred by 65.7% of respondents, while direct composite resin restorations were used by 12.1% amalgam users were only 4.4% of respondents. For the restorative technique, 74.4% of respondents didn't use rubber dam as needed. For the matrix, mylar strip (53.4%), metal matrix (33.8%) and Palodent system (6.5%) were used. 99.6% of respondents restored the Class II cavity by incremental layering. Obtaining of the tight interproximal contact was considered as the most difficult procedure (57.2%) followed by field isolation (21%). Among various bonding systems, 22.6% of respondents preferred SE Bond and 20.2% used Single Bond. Z-250 was used most frequently among a variety of composite resins.

The effect of marginal microleakge according to thickness of flowable resin / 대한치과보존학회지

This study investigated the effect of thickness of flowable resin lining on marginal leakage in class II composite restorations. 80 experimental teeth were prepared with class II preparations with enamel margin or dentin margin. Each group was devided into four groups according to flowable resin lining thickness ; Control group - no flowable resin lining, Group 1 - 0.5 mm flowable resin lining, Group 2 - 1 mm flowable resin lining, Group 3 - 2 mm flowable resin lining. The cavities were restored using Scotchbond Multi-Purpose adhesive system, Filtek Flow and Filtek Z 250 composite resin. Following one day storage in distilled water, the restored teeth were thermocycled for 500 cycles and immersed in 2% methylene blue for 24 hours. The results of this study were as follows: 1. Ranking of mean microleakage scores at the enamel margins was Group 1 < Control = Group 2 < Group 3. The microleakage of Group 3 was significantly higher than that of Control, Group 1 and Group 2 (p < 0.05). 2. Ranking of mean microleakage scores at the dentin margins was Group 1 < Group 2 < Control < Group 3. The microleakage of Group 3 was significantly higher than that of Control, Group 1 (p < 0.05). 3. Compared with microleakage between the enamel and dentin margins, enamel margin group were significantly lower than dentin margin group.