RESUMEN
Extra oral sinus of odontogenic origin occurs when the purulent by-products of dental pulp necrosis spread along the path of least resistance from the root apex to the skin on the face. Patients presenting with cutaneous sinus usually visit a general physician or dermatologist first, as the lesion can mimic various dermatologic pathologies, ranging from an infected sebaceous cysts to a basal cell carcinoma. Despite systemic antibiotics, symptoms often persist causing further confusion, and at times leading to unnecessary surgical interventions. The location of this sinus in the head and neck region should lead the physician to seek a dental opinion in order to avoid misdiagnosis.
RESUMEN
AIM: To assess the microtensile bond strength of repaired composite resin that was surface treated by diamond point or silicon carbide followed by bonding using either only total- etch bonding regimen or silane coupling agent with adhesive resin. MATERIALS AND METHODS: Fourteen composite blocks were aged under deionized water for 14 days. The bonding surface was prepared with coarse diamond point or silicon carbide. Two blocks with no surface treatment were used as control groups. The bonding regimen was either total-etch bonding regimen or silane coupling agent and bonding agent. The aged samples were then bonded to new composite. Five sections per block (each 1mm thick) were prepared; cut to obtain an adhesive zone of approximately 1mm(2) and subjected to microtensile bond strength testing. RESULTS: The highest bond strength was obtained by surface treatment by coarse diamond point and total etch bonding regimen and least by silicon carbide and silane. A statistically significant difference was seen in all the four groups. CONCLUSIONS: Surface treatment by a coarse diamond point and total-etch bonding regimen provides highest bond strength. Thus, a simpler treatment regimen can contribute to a better bond strength in repaired composites.
RESUMEN
AIM: This study was designed to compare the accuracy of Root ZX and SybronEndo Mini, electronic apex locators (EALs), in the presence of various irrigants. MATERIALS AND METHODS: Sixty extracted, single-rooted human teeth were decoronated and the root canals coronally flared. The actual length (AL) was assessed visually and teeth mounted in the gelatin model. The electronic length (EL) measurements were recorded with both EALs in the presence of 0.9% saline; 1% sodium hypochlorite (NaOCl); 2% chlorhexidine digluconate (CHX), and 17% EDTA solution, at "0.5" reading on display. The differences between the EL and AL were compared. RESULTS: The accuracy of EL measurement of Root ZX and Sybron Mini within±0.5 mm of AL was consistently high in the presence of NaOCl and found to be least with EDTA. CONCLUSION: EL measurements were shorter with 1% NaOCl, whereas longer with 2% CHX for both the devices. Sybron Mini was more accurate with 1% NaOCl and 2% CHX than Root ZX.
RESUMEN
AIMS: This study was undertaken to determine the effect of step-curing, ramp curing, single intensity on the effectiveness of cure and polymerization shrinkage of composite resin. The influence of filler loading on the effectiveness of cure and polymerization shrinkage of composite resin was investigated. MATERIALS AND METHODS: In this study, a total of 80 specimens divided into four groups were used. Group I - specimens cured with the step-cure mode. Group II - specimens cured with single high intensity. Group III - specimens cured with the ramp-cure mode. Group IV - specimens cured with single low intensity. Each group had two subgroups based on the composite resins used for making the specimen. The effectiveness of cure was determined from surface hardness values obtained from Rockwell hardness testing. A mathematical volumetric method was used to assess the volumetric shrinkage. RESULTS: Group III showed the best effectiveness of cure followed by group I and II. Group IV showed the least. Polymerization shrinkage was highest with group III and group II, were as was lowest for group I and IV. Charisma showed better effectiveness of cure and low polymerization shrinkage compared to Durafill VS. CONCLUSION: This study emphasizes on the fact that, the soft-start polymerization modes (step curing and ramp curing) should be preferentially used over the conventional single (high or low light) intensities to cure composite resins, as its use results in optimal properties.
RESUMEN
AIMS: The objective of thisstudy is to evaluate and compare 4% titanium tetrafluoride with 2% Sodium fluoride, and the bond strength of composite resin with dentin and their effects on the smear layer. MATERIALS AND METHODS: Fifty freshly extracted non-carious molar and premolar teeth were selected. The occlusal surfaces of the teeth were ground, to prepare flat dentin surfaces at a depth of 2 mm and were randomly grouped with 10 specimens in each. Group I (Etching + Adhesive + Composite resin) was taken as a control group. In Group II, 4% titanium tetrafluoride was applied before etching and in Group III, 4% titanium tetrafluoride was applied after etching. In Group IV, 2% Sodium fluoride was applied before etching and in Group V, 2% Sodium fluoride was applied after etching. Shear bond strength was tested using the Lloyds Universal testing machine and was recorded in MPa. RESULTS: The results were statistically analyzed using the one-way Anova test. Group III showed the highest bond strength among the experimental groups, but less than the control group. CONCLUSIONS: Under the conditions of this in vitro study, titanium tetrafluoride did not significantly affect the bond strength of the composite. Sodium fluoride was found to deleteriously affect the bond strength of the composite.