ABSTRACT
The simplicity of reattaching a fractured segment following dental trauma is astonishing to the dentist as well as the patient. Since the development of adhesive dentistry, reattachment of a fractured tooth fragment has become more and more accepted. Patients would prefer to keep their own tooth even if reattachment would not necessarily provide long-term durability. This study aimed to infer the long-term success rate of reattachment techniques through testing the fracture resistance and microleakage of anterior fractured teeth reattached using different techniques and materials, compare it to tooth's original fracture resistance, and to that of conventional resin composite buildup. Seventy five sound human.incisors were fractured using a universal testing machine by applying a perpendicular, force in a labial-to-lingual direction at a crosshead speed of 1.0 mm/min. The teeth were divided into five groups of 15 teeth each; according to the technique used for reattachment; Group I: simple reattachment, Group II: reattachment and placement of silica at the interface, Group III: reattachment and placement of chamfer at the interface, Group IV: reattachment and internal groove preparation inside the tooth, and Group V: composite build up [Control]. Each group was further subdivided into three subgroups of 5 teeth each, according to the material used. In subgroup 1 reattachment of tooth fragment was performed using Excite adhesive system, in subgroup 2 Tetric Flow resin composite, while in subgroup 3 Rely X dual ci microg resin cement was utilized. The teeth were then immersed in 1% aqueous solution of Mythelene Blue dye for 4 hours to assess microleakage at the interface. The specimens were loaded in a universal testing machine as before until failure. The force required to detach each fragment was recorded. For each tooth, the fracture strength was expressed as a percentage of the load required to fracture the sound tooth [% strength recovery]. The teeth were then assessed for microleakage along the fractured interface using a binocular stereomicroscope and given a score according to the extent of d
ABSTRACT
The ideal dental restorative material and associated techniques continue to be the goal of materi- scientists and clinicians alike. The [gold standard] for restoration quality is considered to be its long term performance in clinical service. However, laboratory tools are useful as indicators of the clinical performance of restorations. An increase in surface roughness has been used as a criterion to assess and predict the clinical deterioration of restorations of different types of material. This study was conducted to assess surface roughness of four direct cosmetic restorative materials; a resin modified glass ionomer [Photac-Fil], a compomer [Dyract], a flowable resin composite [Tetric Flow] and a packable composite [Tetric Ceram HB] at different storage media. A total of 60 disc-shaped specimens [2x2 mm] were prepared, 15 for each material. Baseline surface roughness measurement [Ra value] was performed using image analysis method. Then, each group was divided into three sub groups [n = 5] according to the pH of the storage media used pH 2.5, pH 4 and pH 6.8. Surface roughness assessment was performed using the same method after a storage period of three months. Data were submitted to Duncan's Multiple Range Test to identify significant difference in Ra values among the variables analyzed [restorative materials and storage media]. The results showed no significant difference between restorative materials tested at baseline measurements. However, after the storage period all restorative materials showed a significant increase in surface roughness [Ra value] in all pH storage media compared to baseline Ra measurements. Regarding the pH storage media, a statistically significant difference was found in Ra value of all restorative materials. Increase in acidity of the storage media, increases the surface roughness of the restorative materials. While regarding the restorative material interaction, at pH 4 and at pH 6.8 no significant difference in Ra values was revealed between any of the restorative materials. However, at acidic pH 2.5 packable composite showed a significantly higher mean Ra value than that of compomer and flowable composite. It was therefore concluded that, pH challenge of direct cosmetic restorative materials* remarkably increased the surface roughness of all restorative materials tested, especially at acidic pH. Moreover, the effect of pH on the surface roughness of the materials was not material-dependent except at highly acidic challenge. Clinical Relevance An acidic oral environment may adversely affect long-term clinical performance of direct esthetic restoratives. Careful selection of restorative materials is crucial in patients with history of gastric flux, eating disorders or increased consumption of dietary acids. All current cosmetic restoratives require ongoing maintenance, including periodic repolishing