The purpose of this prospective study was to evaluate the incidence of postoperative pain after intracanal procedures based on an antimicrobial strategy. Data were examined from 627 teeth that had necrotic pulps or required retreatment. Information was obtained for each patient treated with regard to presence of preoperative pain. Occurrence of periradicular bone destruction detected by radiographs was also recorded. The operators consisted of undergraduate students, who were in their first year of clinical training. Root canals were instrumented and then medicated with a calcium hydroxide/camphorated paramonochlorophenol paste. No systemic medication was prescribed. Approximately 1 week after the initial appointment, patients were asked about the occurrence of postoperative pain and the level of discomfort was rated as no pain, mild pain, moderate pain, or severe pain. Data were statistically analyzed using the Chi-square test. Mild pain occurred in 10% of the cases, moderate in 3.3%, and severe (flare-up) in 1.9%. Postoperative pain was significantly associated with the treatment of previously symptomatic teeth without periradicular lesions (p < 0.01). No other correlations were detected between the occurrence of postoperative discomfort and other clinical conditions. There was also no difference regarding the incidence of postoperative pain between treatment and retreatment (p > 0.01). The intracanal procedures used in this study to control root canal infections showed a small incidence of postoperative pain, particularly flare-ups, even performed by inexperienced undergraduate dental students.

Endodontic sealers that possess both optimum flow ability and antimicrobial properties may theoretically assist in the elimination of microorganisms located in confined areas of the root canal system. The antimicrobial effects and the flow rate of the following sealers were investigated and compared: Kerr Pulp Canal Sealer EWT, Grossman's Sealer, ThermaSeal, Sealer 26, AH Plus, and Sealer Plus. The agar diffusion test was used to assess the antimicrobial activity of the sealers. In the flow assay, the sealers were placed between two glass slabs and a weight of 500 g was placed on the top of the glass. The diameters of the formed discs were recorded. All root canal sealers tested showed some antimicrobial activity against most of the microorganisms. There were no significant differences between the materials tested (p > 0.05). All root canal sealers also flowed under the conditions of this study. Statistical analysis of the results revealed that AH Plus and Kerr Pulp Canal Sealer EWT had flow values significantly superior to the other sealers tested (p > 0.05). Taken together, these findings suggest that these sealers have the potential to help in the microbial control in the root canal system.Endodontics is essentially a clinical discipline concerned with the prevention and control of the root canal infection. Cleaned and shaped root canals must be three-dimensionally filled, eliminating the empty space, which has the potential to be infected or reinfected. In addition, by creating a fluid-tight apical, lateral, and coronal seal, root canal fillings may confine residual initants within the root canal system, impeding their egress to the periradicular tissues. A fluid-tight seal of the root canal system also prevents both coronal recontamination by saliva and seeping of periradicular tissue fluids into the root canal, denying a nutrient supply to the remaining microorganisms. Therefore, root canal obturation plays an important role in both the prevention and control of endodontic infections (1).Most root canal filling techniques use core materials associated with endodontic sealers. Core obturating materials, such as guttapercha, usually occupy space, whereas the endodontic sealers enhance the possible attainment of an impervious seal by serving as a filler for canal irregularities and minor discrepancies between the root canal wall and the core material. Several properties are required to an ideal endodontic sealer (2). Among them sealing ability, biocompatibility, and antimicrobial activity probably influence the success of the root canal treatment (1).To create and maintain a three-dimensional seal of the entire root canal system, sealers should have adhesiveness, be dimensionally stable, be insoluble to oral and tissue fluids, and have an adequate flow rate. This latter property allows the material to penetrate into irregularities, isthmi fins and ramifications, which increases the likelihood of obtaining an adequate seal of the root canal system. Moreover, sealers that possess both optimum flow ability and a...

No abstract

This study evaluated the ability of three materials--a resinous root canal sealer (Sealer 26) prepared in a thick consistence, a reinforced zinc oxide-eugenol cement (IRM), and a glass-ionomer cement (Fuji IX)--in preventing bacterial leakage. Retrofilled teeth were mounted in an apparatus and then challenged by human saliva. The number of days required for the bacteria from saliva to penetrate the root-end filling materials was determined. Evaluation was conducted for 60 days. Leakage was observed in all teeth of the Fuji IX group, and in 95% (19 of 20 specimens) of the teeth retrofilled with IRM. Sixty-five percent (13 of 20 teeth) of the teeth retrofilled with Sealer 26 showed leakage. No difference was detected between Fuji IX and IRM (p > 0.05). However Sealer 26 was significantly more effective in preventing bacterial leakage when compared with other materials tested (p < 0.05).

Evidence suggests that diabetic patients are more significantly affected by problems of endodontic origin. This study sought to radiographically and histologically examine the development of periradicular inflammation in control and in diabetic rats after induction of pulpal infection. The pulps of the mandibular first molars of normal and streptozotocin-induced diabetic rats were exposed and left in contact with their oral cavities for 21 and 40 days. Afterwards, the animals were sacrificed, the mandibles were surgically removed, fixed in formalin and then radiographed in a standardized position. The radiographic images of the periradicular lesions were scanned and computerized images were evaluated for the total area of the lesions using a specific software. Representative specimens were also prepared for histopathological analysis. Radiographic analysis revealed that diabetic rats presented significantly larger periradicular lesions when compared with control rats, regardless of the experimental period (p<0.05). Histopathological examination of representative specimens revealed larger periradicular lesions and more severe inflammatory exudate in the group of diabetic rats when compared with the control group. Data from the present study indicated that diabetic rats can be more prone to develop large periradicular lesions, possibly due to reduction in the defense ability against microbial pathogens.