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.

Evaluation of clinical effect of porcelain fused for metal crown restoration after root canal therapy / 医疗卫生装备

Objective To investigate the clinical effect of porcelain fused for metal crown restoration after root canal therapy.Methods Totally 90 patients with pulpitis or periapical periodontitis from December 2013 to December 2015 had their clinical data analyzed,who underwent root canal therapy and were divided equally into an observation group and a control group.The observation group took porcelain endocrowns repair and the control group applied ceramic crown.The two groups were compared on the restoration integrity,edge sealing,residual rate,gum,food impaction and color 3 months,6 months and 1 a after treatment.Results The observation group behaved significantly better than the control group in the edge sealing and restoration integrity (P＜0.05).There were significant differences between the residual rates,gum and food impaction in the two groups (P＜0.05).Conclusion Porcelain endocrowns repair gains advantages over ceramic crown repair in edge sealing,integrity,gum,food impaction and color after root canal therapy,though its long-term effect needs further investigation.

Evaluation of clinical effect of porcelain fused for metal crown restoration after root canal therapy / 医疗卫生装备

Objective To investigate the clinical effect of porcelain fused for metal crown restoration after root canal therapy.Methods Totally 90 patients with pulpitis or periapical periodontitis from December 2013 to December 2015 had their clinical data analyzed,who underwent root canal therapy and were divided equally into an observation group and a control group.The observation group took porcelain endocrowns repair and the control group applied ceramic crown.The two groups were compared on the restoration integrity,edge sealing,residual rate,gum,food impaction and color 3 months,6 months and 1 a after treatment.Results The observation group behaved significantly better than the control group in the edge sealing and restoration integrity (P＜0.05).There were significant differences between the residual rates,gum and food impaction in the two groups (P＜0.05).Conclusion Porcelain endocrowns repair gains advantages over ceramic crown repair in edge sealing,integrity,gum,food impaction and color after root canal therapy,though its long-term effect needs further investigation.

The effects of the treatment of early cracked teeth with vital pulp preservation / 实用口腔医学杂志

Objective:To investigate the effects of the treatment of early cracked teeth with vital pulp preservation.Methods:63 early cracked teeth with vital pulp in 56 patients were treated by light cured composite resin filling with or without MTA rebasing,and restored by precious metal crown.The patients were followed up for 2 years.Results:After 2 years follow-up,57 teeth were successfully treated and failure was found in 6 teeth,the effective rate was 90.4％.Conclusion:Light cured resin filling directly or with MTA rebasing for early cracked teeth with vital pulp,and restoration by precious metal crown are effective in the treatment of early cracked teeth with vital pulp.

An in vitro study to evaluate retentive property of resinous dental adhesives and other dental luting cements.

Background: Retention of crowns depends on various factors such as the retentive properties of the luting cements and the type of cast metal. Limited information is available regarding the retentive strengths of crowns, cemented with resin cements. Objective: The purpose of the study was to evaluate the retentive property of resinous dental adhesives with three other luting cements. Material and methods: Twenty freshly extracted human sound first mandibular molar was used for the study. The root of each tooth was embedded into a cylindrical shape block of self cured resin. Each of the tooth samples was prepared to receive a full metal crown. Total samples were divided into four groups, each containing five samples, for cementation of the metal crown in order to compare retentive properties of resinous adhesive and other luting agents; group A- resinous adhesive Panavia, group B - Zinc Phosphate cement, Group C- Glass ionomer cement, and group D- polycarboxylate cement. After 10min of cementation, the retention test was performed in an Instron tensile testing machine, to analyze the retentive properties of different luting cements. A one-way analysis of variance was used to analyze the data, with a significance level of alpha =.05. Results: Result showed a maximum mean retentive strength in Panavia Ex. (281.34kg), followed by Glass Ionomer (70.21kg), Polycarboxylate (63.06kg), and least in Zinc Phosphate cement (40.31 kg), which was statistically significant. Conclusion: Within the limitation of the present study, it was concluded that resinous adhesive Panavia Ex. cement has better retentive properties compare to other luting cements.

Full Mouth Rehabilitation in a Patient with Amelogenesis Imperfecta: Treatment for Aesthetic and Functional Improvement.

Introduction: Amelogenesis imperfecta (AI) is a dental anomaly that causes defects in enamel with no evident association of systemic disease. Presentation of Case: This clinical report describes the oral rehabilitation of a 24-year-old woman diagnosed as having hypoplastic type of amelogenesis imperfecta along with palatally positioned maxillary lateral incisors. The aim of the treatment was to eradicate dental sensitivity, to correct of maxillary anterior malocclusion, and to restore esthetics and masticatory function. The treatment included removal of maxillary lateral incisors and placement of metal-ceramic fixed bridge dentures, as well as placement of all ceramic, metal-ceramic and full metal crowns for other affected teeth. Discussion: Interdisciplinary approach of the management of AI is necessary. Depending on the type and severity of the disorder, esthetic and functional concerns, prosthetic management of anterior teeth, like complete crowns, porcelain laminate veneers are the best options. For many years the most predictable and durable esthetic restoration of anterior teeth has been complete crowns. Conclusion: Porcelain bonded to metal fixed bridge partial dentures and full ceramic, porcelain bonded to metal and full metal crowns to correct the malocclusion and aesthetic problem, to eradicate sensitivity and to restore the masticatory function in this case was satisfactory.

Assessment of convergence angle of full-coverage porcelain fused to metal crowns in clinical practice.

Background: Full-coverage porcelain fused to metal crowns is commonly recommended for restoration of extensively damaged teeth. Ability of the dentist to adequately prepare teeth is fundamental to success and longevity of these restorations. Aims: This study was designed to compare recommended convergence angle and taper values of tooth preparation with clinically practiced values and to assess the factors such as tooth position, operator experience, vitality, and restorative status on convergence angle of prepared teeth. Setting and Design: It was a descriptive, cross-sectional study design and held at The Aga Khan University Hospital, Dental Section, for a period of 1 year. Materials and Methods: A minimum of 197 crown preparation models of molar and premolar teeth prepared by residents and specialists were collected in order to achieve the objectives of the study on the basis of convenient sampling technique. Statistical Analysis: One sample t-test used to compare the mean practiced convergence angle values with its recommended values. Independent sample t-test and one-way ANOVA was used to see difference in the convergence angle values of the teeth prepared by different operators, tooth type, vitality status, and restorative status of teeth. Results: Mean reported convergence angle and axial wall taper values were 23.7°±8.9° and 11.3°±7.8°, respectively, which is significantly greater (P<0.001) than the recommended values. Convergence angle values were greater for molars as compared to premolars. Conclusion: There was a considerable disparity between the convergent angles values recorded in this study and the recommended guidelines and are affected by tooth type, vitality, and restorative status of tooth.

Bond-strength of several metal-meramic alloys and meneered-porcelain / 대한치과보철학회지

PURPOSE: In this study, we evaluated the bond-strength between a few metal ceramic-alloys and veneered-porcelain and found if the bond strength of metal-ceramic alloy with lower gold content than the presently used gold alloy was high enough. MATERIALS AND METHODS: For this study, after plasticizing porcelain only for gold alloy, metal specimen was fabricated using Ni-Cr alloy and gold alloy with different gold content. Three point flexural test were performed to measure their bond-strength. RESULTS: The bonding strength of Group 1 to porcelain was 40.62 +/- 3.32 MPa, which was the highest (P.05), while there was a significant difference between that of Group 2, Group 3 and Group 4 and that of Group 6 (Duncan's test, P<.05). The bonding strength between gold alloy and porcelain increased according to the content of gold. In all experimental groups showed higher value than 25 MPa, which is the least value recommended by ISO 9693. CONCLUSION: In all groups, bonding strength was higher than 25 MPa, which is the least value of ISO9693. Therefore, it is considered that metal gold alloy with low gold content is clinically usable.

The effect of pulp conservative restoration for early cracked teeth / 实用口腔医学杂志

38 molars diagnosed as early cracked teeth and without pulpitis were selected to carry out the clinical observation. All the teeth were prepared and restored by metal crown under local anesthesia. After 1-15 years follow-up, the efficiency was 84.20% and all the tested teeth showed no symptoms of pulpitis and kept good chewing function. The results suggests that for the teeth diagnosed as early cracked molars and without pulp inflammation, making metal crown with less dentin loss is a safe and scientific treatment method.

Uso do núcleo metálico fundido na reconstrução de dentes tratados endodonticamente: relato de caso clínico / Casting metallic nucleus use in thereconstruction of endodonticallytreated teeth: a case-report

A restauração de dentes tratados endodonticamente é um aspectoimportante que envolve múltiplas opções de tratamentos de complexidade variável.A decisão do material e da técnica para restaurá-los é um tema polêmicona literatura odontológica. Para dificultar ainda mais a seleção, uma grande variedadede alternativas restauradoras está disponível no mercado atualmente. Oobjetivo deste artigo é mostrar que o núcleo metálico fundido ainda tem sua indicaçãoe apresentar um caso clínico de dente reconstruído com núcleo metálicofundido e coroa metalocerâmica.

The restoration of endodonticallytreated teeth is an important aspect involvingmultiple treatment options with a range of complexity.The choice of the material and the techniqueused to restore the teeth is still controversial in theliterature. To make the selection even more difficulta great variety of restoring alternatives is availablein the market today. The objective of this article isto show that casting metallic nucleus still have itsindication and to present a report case of a toothreconstructed with casting metallic nucleus andporcelain fused to metal crown.

Evaluation of clinical esthetical effect in cervical margin of porcelain-fused-metal crown restoration / 中华医学美学美容杂志

Objective To evaluate the clinical esthetical effect in the cervical margin of the porcelain fused to metal crown restoration.Methods 225 cases with the porcelain fused to metal crown were observed.The evaluator examined these restorations for cervical color,marginal fit,and gingival state.(Results 53) cases of restoration changed in the cervical color.The method and the tooth preparation volume,the procedure and the material,which were all closely relevant to the cervical color change.(Conclusion Using)the correct method,improving the procedure and choosing the proper material would reduce the cervical color change.

Esthetic evaluation in restoring anterior teeth with porcelain fused to metal crown / 中华医学美学美容杂志

Objective To compare and analyse the esthetic effect of four kinds of the porcelain fused to metal crowns (PFMs) in restoring anterior teeth. Methods Based on single standard, a total of 371 anterior teeth from 110 patients were restored by PFM, in which 206 teeth of 59 patients were restored with Ni-Cr alloy PFM, 105 teeth of 29 patients with full circular procelain shoulder PFM, 35 teeth of 16 patients with titanium metal PFM, and 25 teeth of 6 patients with noble metal PFM. The esthetic effect was examined and analysed by single-blind method in one week and after one year. Results Between three days and one week, there was no difference among four PFMs in shapes and colors, which corresponded with adjacent teeth. The edge suitability was good and no significance was found in them. After one year, there was no difference of four PFMs in shapes and colors, which corresponded with adjacent teeth. The edge suitability of noble metal PFM was better than the other three, and the difference was statistically significant. Conclusion The esthetic effect is the best when noble metal PFM is used to restore anterior teeth and better with full circular procelain shoulder PFM.

Effects of microstructure grinded on the labial face of PFM on esthetic prosthesis for anterior teeth / 中华医学美学美容杂志

Objective To explore the effects of microstructure grinded on the labial face of porcelain fused to metal crown (PFM) in esthetic prosthesis for anterior teeth. Methods 193 patients with single maxillary incisor tooth defects were repaired with 2 crowns for each one. After the crowns being blent colour and molded, the crown A was not grinded particularly on the labial face and the crown B was done according to the records of the microstructure.The patients were allowed to choose the most satisfied one when 2 crowns were cemented temporarily. Results 36 patients chose the crown A and 157 chose B.The difference was significant ( P0.05). Conclusion The crown has great vitality and accordes with the esthetic standards of the patients by way of being grinded microstructure on the labial face.

Contents of Ni and Cr in hair after wearing Ni-Cr based porcelain-fused-metal (PFM) crown / 实用口腔医学杂志

0.05). Conclusion:After Ni-Cr-Based porcelain-fused-to-metal crown application, the metal ion can be released and absorbed by human body. But the content is almost harmless to human body.

The influence of repeated firings on the color of porcelain-fused-to-metal crown restoration / 实用口腔医学杂志

s〕 Objective:To investigate the influence of repeated firings on the color of porcelain fused to metal crown(PFM) . Methods: 5 PFM samples were prepared and fired for 9 times.The color of the samples was measured following firing with CIE1976 L*a*b* color system . The color difference ?E ab *,hue angle h ab * and chroma C ab * were calculated according to the following calculations:?E ab * ={(?L*) 2 +(?a*) 2 +(?b*) 2} 1/2 , C ab * ={(a*) 2+(b*) 2} 1/2 , h ab *=tg 1 b*/ a*, L* presented brightness. Results: After repeated firing, L* value of PFM , C ab * and L* value of dentin layer and h ab * value of opaque layer increased. Conclusion: The color of PFM after repeated firing may become brighter. The color change is resulted from the increase of L* and C ab * of dentin layer.