Solubility of two root-end filling materials over different time periods in synthetic tissue fluid: a comparative study

Statement of the Problem: Insolubility is an important criterion for an ideal rootend filling material to both prevent any microleakage between the root canal and the periradicular space and provide sealing ability

Purpose: Many recent studies have shown that mineral trioxide aggregate [MTA] and calcium-enriched mixture [CEM] have acceptable sealing ability. The purpose of this in vitro study was to evaluate the solubility of these root-end filling materials

Materials and Method: Forty stainless steel ring moulds with an internal diameter of 10 +/- 1 mm and a height of 2 +/- 0.1 mm were selected. Samples of MTA and CEM were mixed according to the manufacturer's instructions and inserted into the moulds. The specimens were divided into 4 experimental groups and kept in synthetic tissue fluid [STF] for 2 different time periods [7 and 28 days]. The control group contained 8 empty rings. The moulds' weights were recorded before and after immersion in STF. The changes in the weight of the samples were measured and compared using a two- way ANOVA test at a significance level of 5%. Specimens were evaluated with scanning electron microscopy [SEM] at a magnification of 500×

Results: There was no significant difference in weight changes between MTA and CEM samples [p> 0.05]

Conclusion: MTA and CEM have similar solubility in STF in different time periods

Short term effect of calcium hydroxide, mineral trioxide aggregate and calcium-enriched mixture cement on the strength of bovine root dentin

Some studies in dental literature have proposed that short term and long term exposure of root dentin to calcium hydroxide predisposes it to fracture. Mineral trioxide aggregate [MTA] and a recently introduced endodontic material, calcium-enriched mixture [CEM] cement may be used instead of calcium hydroxide and might have an effect on the strength of root dentin. Therefore, the aim of this in vitro study was to compare the short-term effect of calcium hydroxide, MTA and CEM cement on the strength of bovine root dentin. In this experimental study, 15 freshly extracted intact bovine incisors were selected. A cylinder with uniform wall thickness [internal diameter of 2.5 and external diameter of 5.5] was prepared. The cylinders were cut longitudinally into 4 symmetrical pieces. The 60 prepared samples were divided into four groups [n =15]. The samples were placed in 4 petri-dishes containing calcium hydroxide, MTA, CEM cement and normal saline as the control group. They were then subjected to flexural forces applied by Instron universal machine. Data was analyzed using ANOVA and Tukey test. The mean flexural force in the calcium hydroxide, MTA and CEM cement groups was significantly lower than that in the control teeth [77.9 N, 90.66 N, 94.40 N, compared to 125.12 N respectively, P=0.001]. There were no significant differences between calcium hydroxide, MTA and CEM cement group. MTA and CEM cement decreased the flexural strength of bovine root dentin, like their counterpart calcium hydroxide. Further studies are required to determine the effect of these materials on human root dentin clinically

Success rate of nonsurgical endodontic treatment of nonvital teeth with variable periradicular lesions

Bacterial infection of tooth pulp can progress into periapical diseases. Root canal treatment has been established as the best treatment. In cases of failure, nonsurgical retreatment of teeth is preferred to surgical procedure and extraction. In this historical cohort study, 104 permanent teeth with apical lesion were treated during 2002-2008. All teeth showed radiographic evidence of periapical lesion varying in size from 1 to >10mm. A total of 55 teeth were treated with initial root canal treatment and 49 teeth required retreatment. Patients were recalled up to 7 years. All radiographs were taken by RSV MAC digital imaging set and long cone technique. The presence/absence of signs and symptoms and periapical index scores [PAI] were used for measuring outcome. Teeth were classified as healed [clinical/radiographic absence of signs and symptoms] or diseased [clinical/radiographic presence of signs and symptoms]. The data were statistically analyzed using student t-test and Pearson chi-square or fisher's exact test. The rate of complete healing for teeth with initial treatment was 89.7%, and for retreatment group was 85.7%; there was no significant difference. Size of lesions did not significantly affect the treatment outcomes. Success of tooth treatment did not reveal significant correlation with gender and number of roots. Orthograde endodontic treatment/retreatment demonstrates favorable outcomes. Thus, nonsurgical endodontic treatment/retreatment should be considered as the first choice in teeth with large periapical lesion

Antibiotic prescription for endodontic treatment: general dentist knowledge + practice in Shiraz

Diseases of the dental pulp and periapical tissues are chiefly caused by microorganisms. Antibiotics are used in some endodontic cases; however, successful cases can predominantly be achieved by mechanical and chemical cleaning of the canal or surgical intervention. The aim of this study was to determine the knowledge of General Dental Practitioners [GDPs] in Shiraz in respect to antibiotic prescriptions during and after endodontic treatment. A one-page questionnaire was sent to 200 active general dentists. Of the 120 surveys returned, 93 were accepted. The data were analyzed using t-test, Chi-square, ANOVA and Fisher's Exact Test. Only 29% of dentists had full knowledge [correct answers to all questions] of antibiotic prescription protocols in pulpal and periapical disease. Amoxicillin 500 mg capsule was the drug of choice of dentists. Total of 42% of GDPs had full knowledge of antibiotic prescription protocols for persistent or systemic infections cases. GDPs more recently qualified had slightly greater knowledge compared to GDPs with experience; however, this difference was not significant. Also, there was no significant difference between genders. General practitioners' knowledge about antibiotics seems inadequate and further education is recommended to update the practitioners

Management of a crown-root fracture in central incisors with 180 [degree sign] rotation: a case report

The crown-root fracture is a common tooth injury which compromises the biological width and need proper endodontic and prosthodontic treatment to achieve acceptable clinical outcome. This case report describes clinical management of crown-root fracture in maxillary central incisors which was successfully treated by forceps eruption with 180 [degree sign] rotation to restore the biological width. The patient was followed-up for 18 months. Clinical and radiographic evaluation showed acceptable results, the replanted teeth have normal function and no obvious inflammatory root resorption was seen on radiographic examination

Comparison of apical debris extrusion using a conventional and two rotary techniques

Preparation techniques and instruments produce and push debris out of canals. This can induce inflammation within the periapical area. Therefore, instrumentation that causes less extrusion of debris is more desirable. The purpose of this in vitro study was to evaluate the quantity of debris extruded from the apical foramen during root canal preparation by using one hand and two rotary instrumentation techniques. Three different groups each with 12 mesiobuccal roots of human maxillary first molar were instrumented using either step-back technique with hand instruments, FlexMaster or Mtwo rotary system. Debris extruded from the apical foramen during canal preparation was collected. The mean dry weights of debris were compared using one-way ANOVA. Step-back group had a significantly greater mean weight of debris compared to the other two groups [P<0.05]. Mtwo group had the lowest mean weight of debris, though it was not significantly different from FlexMaster group. According to this study, the engine driven techniques were associated with less apical debris extrusion