A Comparative study of shear bond strength of repaired porcelain fused metal restorations and its interface adaptation: An In Vitro study

INTRODUCTION : The smile is one of the most appealing aspects of the human face and is considered to be very image of the soul. An esthetically pleasing appearance of teeth is the best asset for a good smile. Esthetics is a demanding factor when the restoration in the missing anterior esthetic zone is considered and achieving balance between the functional stability and cosmetic appeal has been a major challenge to the dental professionals Porcelain was successfully adapted for dental restorations by the end of the 1800s. Though earlier all porcelain crowns fulfilled the esthetic demand the inherent brittleness of these crowns, lack of marginal integrity, difficulty of cementation and questionable survival made them to meet the functional requirement which limit their use in dentistry. AIMS AND OBJECTIVES : AIM: To evaluate the shear bond strength of repaired porcelain fused metal restorations by using different types of commercially available composite restorative materials. OBJECTIVES OF THE STUDY: 1. To evaluate the shear bond strength of fractured ceramic using different commercially available composite resins keeping surface treatment of metal and ceramic standard. 2. To compare the shear bond strength of fractured ceramic using different commercially available composite resins keeping surface treatment of metal and ceramic standard. 3. To evaluate the bonding ability at the interface between composite resin and the metal. 4. To evaluate the bonding ability at the interface between composite resin and the ceramic. MATERIALS AND METHODS : The present invitro study was conducted to evaluate and to compare the shear bond strength of repaired porcelain fused restorations using different commercially available composite resins. This study also involved to evaluate the bonding ability at the interface between composite resin-metal and composite resin- ceramic interface. GROUPING OF SAMPLES : The study was categorized based on the different types of commercial composite restorative materials used, and classified into four groups with one control group of 10 specimens and 11 specimens in each test group. So a total of 43 specimens were prepared. GROUP A: control group-consists of 10 samples for porcelain fused metal disc, GROUP B: consists of 11 samples for Ivoclar composite resin, GROUP C: consists of 11 samples for 3M composite resin, GROUP D: consists of 11 samples for Dentsply composite resin. RESULTS : This invitro study was performed to evaluate and to compare the shear bond strength of repaired porcelain fused metal restorations by using different types of commercially available composite restorative materials and its interface adaptation. Samples were divided into four groups, with one control group (Porcelain Fused Metal restorations) of 10 specimen and three test groups based on types of composite materials of 11 specimens each (Ivoclair, 3M, Dentsply). 10 samples from control group and 10 samples from three test groups were tested for shear bond strength test after thermocycling and 1 sample from each test group were tested for bonding interface adaptation. Data obtained as each group as mentioned below and were subjected for statistical analysis. SUMMARY AND CONCLUSION : Ceramic materials provide an excellent restorative service over years however the fracture of Porcelain Fused Metal restorations is a common problem faced in routine practice. Making of a new prosthesis in most of the instances is both costly and time consuming and hence repair may be indicated. The suitable repair material which is regularly used in repair of Porcelain Fused Metal restorations is composite resins. This Invitro study was performed to evaluate and to compare the shear bond strength of repaired porcelain fused metal restoration by using different types of commercially available composite restorative materials and its interface adaptation. Samples were divided into four groups, with one control group (Porcelain Fused Metal restoration) of 10 specimen and three test groups based on types of composite restorative materials of 11 specimens each. (Ivoclar, 3M, Dentsply). 10 samples from control group and 10 samples from three test groups were tested for shear bond strength test and 1 sample from each test group were tested for bonding interface adaptation. The results obtained were statistically analyzed. Within the limitations of the present study and from the results obtained the following conclusions were drawn. 1. The bond strength of conventional feldspathic Porcelain Fused Metal restoration was significantly higher than that of composite restorative materials to metal bonding systems. 2. Ivoclar composite repair material showed higher bond strength values than 3M & Dentsply composite restorative materials. But 3M showed higher bond strength values than Dentsply. 3. Dentsply composite restorative material showed the lowest bond strength values of the three tested material. 4. Bonding interface adaptation was more closer for Ivoclar composite restorative material. The results of the study showed that the Ivoclar composite restorative material could provide better bond strength as compared to that of 3M & Dentsply composite repair materials. However further longitudinal studies under conditions simulating the oral environment are needed to prove the success and longevity of ideal porcelain fused metal repair composite material