Comparison of the Clinical Efficacy and Safety of Different Restorations for Deciduous Teeth Defect / 现代生物医学进展

Objective:To investigate the curative effect of different restorations for deciduous teeth defect of children.Methods:67 children with teeth defecting seriously and being unable to fill restore were enrolled from January 2011 to January 2015 and randomly divided into three groups,one group of patients accepted metal crown restoration (Group A,n=22),one group adopted ceramic inlay restoration (Group B,n=22),and the last one accepted silver amalgam filling (Group C,n=23),the curative effect and incidence of adverse reactions among three groups in the period follow-up were compared.Results:In the period of 18-month follow-up,6 patients of toothache,5 patients of food impaction and crevices between restorations and teeth,3 cases of gingival congestion,2 cases of secondary caries were observed in group C;3 cases of toothache,1 case of food impaction,gingival congestion,crevices between restorations and teeth and secondary caries were observed in group B;2 cases of toothache and food impaction,1 case of gingival congestion were observed in group A.The incidence of adverse reactions in group A and group B was lower than those in group C (P＜0.05),which was lower in group A than that in group B,but no significant difference was found between group A and group B (P＞0.05).Conclusion:The restoration of metal crown and ceramic inlay deserved popularization had better curative effect and safety for deciduous teeth defect of children than silver amalgam filling.

Clinical effect of CEREC chairside on atypical ceramic inlay restoring class Ⅱ cavity / 中华医学美学美容杂志

Objective To evaluate the clinical effect of CEREC chairside on atypical porcelain inlay restoring class [[cavity.Methods 30 patients that required re-treatment because of resin restoration failure and early posterior proximal caries were selected randomly.The original fillings,secondary carious tissues and undercut parts were removed.The clear and round edge lines were prepared.With Sirona CEREC Blocs,35 atypical ceramic inlays were produced in accordance with CEREC AC CAD/CAM standard procedures.After clinical trial and modification,the inlays were bonded with 3M Veneer resin adhesive cement.Evaluation was done immediately and 3,6,12 and 24 months after restoration.Two senior prosthodontists did the evaluation according to the modified USPHS criteria.Results The evaluation results were all A when estimated immediately after restoration.None inlay falled off during the first two years.However,3 inlay were found to be damaged when reviewed at the 24th month.There exsited two patients having mild symptoms of dentine hypersensitivity which appeared at the beginning and died out gradually.Generally speaking,more than 90％ of inlay restorations had reached the USPHS criteria A.Color match and retention represented better effects.Conclusions CEREC atypical ceramic inlays can effectively restore Class Ⅱ cavity,short-term effect is good,but long-term effect still needs further observations.

Stress analysis of two methods of ceramic inlay preparation by finite element.

Objective: Ceramic inlays are bonded to tooth structure with resin cements. During the resin cement setting, shrinkage stress develops at the interfaces. During tooth preparation, the undercut areas formed due to the different patterns of caries progression can either be blocked out before taking impression with suitable cement such as glass ionomer cement, or before making the final restoration in the laboratory. Then, the relieved space will be filled with luting cement in clinic. The aim of this study was to compare these two methods of undercut filling in term of stress distribution in the ceramic inlay. Materials and Methods: An axisymmetric finite element analysis was performed to study the stress distribution during inlay cementing. The solid model was generated from a longitudinal section of maxillary premolar in which a class I cavity with 60 degree undercut at the preparation wall and 20 degree divergence of the vertical walls was prepared. A thermal model was used to simulate the polymerization shrinkage of the resin cement. Finite element analysis was carried out in ANSYS environment. Results: Filling the undercut by glass ionomer cement decreased the stress concentration at the ceramic/cement interface. The dominant normal stress at the tooth cement interface in absence of glass ionomer cement was tensile with maximum of 30 Mpa. Using glass ionomer, cement developed stresses with different compressive and tensile signs. With increasing the thickness of resin cement (100 μm, 150 μm, 200 μm), the stress increased. Conclusion: Cements with minimum shrinkage and as thin layer as possible should be used. Filling the undercut with glass ionomer cement decreases the stress. Other experimental and clinical studies must follow this research.

Shear bond strength of the three different kinds of resin cement on CAD/CAM ceramic inlay / 대한치과보철학회지

PURPOSE: The purpose of this study was to evaluate the bond strengths between the latest CAD/CAM ceramic inlay and various resin cements which are used primarily for esthetic restoration. MATERIALS AND METHODS: Cylindrical ceramic blocks(Height: 5 mm, diameter: 3 mm) were fabricated by using Cerec3 and bonded on the dentin of the ninety extracted caries-free molars using three different kinds of resin cement(Unicem(R), Biscem(R), and Variolink II(R)) according to the manufacturer's instructions. Ninety specimens were divided into 3 groups according to three different kinds of resin cement. Half of each group were conducted thermocycling under the conditions of the 5 - 55degrees C, 5,000 cycle but the other half of them weren't. All specimens were kept in normal saline 37degrees C, for 24 hours before measuring the bond strength. The shear bond strength was measured by Universal testing machine with a cross head speed of 0.5 mm/min. The results were analyzed statistically by t-test and one-way ANOVA. RESULTS: Unicem(R) group showed the highest shear bond strength despite a slight decline by thermocycling. The shear bond strength of Unicem(R) group and ValiolinkII(R) group were significantly influenced by thermocycling, whereas Biscem(R) group was not influenced (P<.05). There were no significant differences in the bond strength between the three groups without thermocycling, but there was significant differences between Unicem(R) group and Valiolink II(R) group with thermocycling(P<.05). CONCLUSION: It has been shown to be clinically effective when the self-adhesive resin cements Unicem(R) and Biscem(R) were used instead of the etch-and-rinse resin cement Valiolink II(R) during the bonding of CAD/CAM ceramic inlay restorations with teeth.

Comparison of fracture resistance of teeth restored with ceramic inlay and resin composite: An in vitro study.

Aim: The aim of this study was to evaluate the in vitro fracture resistance of teeth restored with bonded ceramic inlay and direct composite resin restoration in comparison to the normal tooth. Materials and Methods: This study evaluated the fracture strength of the teeth restored with bonded ceramic inlay and direct composite resin restoration in comparison to the normal teeth. Thirty intact human maxillary first premolars were assigned to three groups: Group 1 - comprising sound/unprepared teeth (control). Group 2 - comprising of Class-II direct composite resin restored teeth and Group 3 - comprising Class-II ceramic inlay restored teeth. Cavities were prepared with occlusal width of 1/3 intercuspal distance and 2 mm deep pulpally. Group 2 teeth were restored with hybrid composite resin (Z350 3M ESPE, USA) and group 3 teeth were restored with Vitadur Alpha alumina (Ivoclare Vivadent, Liechtenstein, Europe). Ceramic inlay was bonded with adhesive cement (rely X resin cement of 3MESPE, USA). The specimens were subjected to a compressive load until they fractured. Data were analyzed statistically by unpaired Student's t test. Results: The fracture resistant strength, expressed as kilonewton (KN), was group 1 - 1.51 KN, group 2 - 1.25 KN, and group 3 - 1.58 KN. Statistically, group III had highest fracture resistance followed by group I, while group II had the lowest average fracture resistance. Conclusion: The fracture resistant strength of teeth restored with ceramic inlay was comparable to that of the normal intact teeth or slightly higher, while teeth restored with direct composite resin restoration showed less fracture resistant strength than that of the normal teeth.

Anti-fracture strength of teeth with wedge-shaped defects repaired with CEREC CAD/CAM ceramic inlay / 第三军医大学学报

Objective To study the effect of CEREC CAD/CAM ceramic inlay on repair of wedge-shaped defects of teeth and test its anti-fracture properties. Methods Extracted teeth were divided into control group ( n = 16) and experimental group ( n = 16) ,and prepared into imitating teeth with wedge-shaped defects. Teeth in experimental and control groups were repaired with CEREC CAD/CAM ceramic inlay and light-cured composite resin,respectively. Anti-fracture strength of teeth with wedge-shaped defects repaired with CEREC CAD/CAM was assayed on a universal testing device with its maximal loading recorded. The anti-fracture strength was compared between the 2 groups. Results The anti-fracture strength of teeth with wedge-shaped defects repaired with CEREC CAD/CAM ceramic inlay was significantly higher in experimental group than in control group ( 3. 56 ? 0. 27 vs 2. 43 ? 0. 15,P