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UNLABELLED: Temperature changes caused by laser irradiation can promote damage to the surrounding dental tissues. In this study, we evaluated the temperature changes of recently extracted human mandibular incisors during intracanal irradiation with an 810-nm diode laser at different settings. Fifty mandibular incisors were enlarged up to an apical size of ISO No. 40 file. After the final rinse with 17% ethylenediaminetetraacetic acid, 0.2% lauryl sodium sulfate biologic detergent, and sterile water, samples were irradiated with circular movements from apex to crown through five different settings of output power (1.5, 2.0, 2.5, 3.0, and 3.5 W) in continuous mode. The temperature changes were measured on both sides of the apical and middle root thirds using two thermopar devices. A temperature increase of 7 °C was considered acceptable as a safe threshold when applying the diode laser. RESULTS: The results showed that only 3.5-W output power increased the outer surface temperature above the critical value. CONCLUSION: The recommended output power can be stipulated as equal to or less than 3 W to avoid overheating during diode laser irradiation on thin dentin walls.

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The success of endodontic treatment depends on the complete elimination of microorganisms from the root canal system, thus the search for new procedures to eliminate them is justified. The aim of this study was to assess bacterial reduction after intracanal irradiation with the Er:YAG laser. The canals of 70 extracted human maxillary canines were prepared up to file #40 using 1% NaOCl, irrigated with 17% EDTA, and then washed with physiological solution activated by ultrasound. The roots were sterilized by autoclaving, inoculated with 10 µl of a suspension containing 1.5 × 10(8) CFU/ml of Enterococcus faecalis ATCC 29212 and incubated at 37°C for 72 h. The canals were irradiated with the Er:YAG laser using two energy settings: 60 mJ and 15 Hz, and 100 mJ and 10 Hz. The remaining bacteria were counted immediately and 48 h after laser irradiation. The results showed a high bacterial reduction at both time points. With 60 mJ and 15 Hz there was an immediate reduction of 99.73% and the reduction was 77.02% after 48 h, and with 100 mJ and 10 Hz there was an immediate reduction of 99.95% and the reduction was 84.52% after 48 h. Although the best results were observed with 100 mJ of energy, the difference between the two settings was not statistically significant. The count performed 48 h after irradiation showed that E. faecalis were able to survive, and can grow even from small numbers.

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OBJECTIVE: The goal of this study was to evaluate the infection control measures actually implemented by dental surgeons during dental practice, as patients and professionals are exposed to high biological risk in dental care environments. METHOD: 614 questionnaires (90.69%) were answered by professionals registered in updating or in post-graduate courses in the Municipality of São Paulo. RESULTS: Out of surveyed professionals 30.62% admitted that surface protection barriers were not used, whereas 34.17% were using non ideal or outdated pre-disinfection practices. The autoclave was used by 69.38% of participants, although 33.80% were not monitoring control of the sterilization cycles. Chemical and biological indicators were not used simultaneously by 83.21% of respondents and were not employed on a daily or weekly basis by at least 81.75%. Dubious methods of sterilization were cited by 44.77%. Occupational accidents caused by cutting and piercing objects were reported by 47.88%; however, the biologic risk was underestimated by 74.15% of the professionals who suffered the accidents. Irritant solutions were used as an antiseptic agent by 18.55%. CONCLUSIONS: Infection control measures reported by dental surgeons during their practices are deficient. It is necessary to educate, raise awareness of professionals, and promote constant updating courses on procedures which aim at improving safety of dental care.

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OBJECTIVES: The objectives of this study were to assess the accuracy of working length determination using 3 electronic apex locators and direct digital radiography and to compare the results with those obtained using the visual method (control measurement). STUDY DESIGN: Twenty extracted human maxillary premolars were selected: 17 two-rooted and 3 single-rooted (total of 37 canals). Working length was measured using electronic apex locators Elements Diagnostic, Root ZX, and Just II. Subsequently, teeth were positioned in the alveolar bone of a dry skull and submitted to direct digital radiography. A variation of ±1 mm was considered as acceptable. Results were analyzed using the Wilcoxon and the χ(2) tests. RESULTS: Results presented an accuracy of 94.6% for Elements Diagnostic, 91.9% for Root ZX, 73.0% for Just II, and 64.9% for direct digital radiography when considering the margin of ±1 mm in relation to the control measurement. Comparisons with the actual control measurements resulted in accuracy results of 13.51%, 13.51%, 10.10%, and 2.70%, respectively. CONCLUSIONS: Root ZX and Elements Diagnostic are more accurate in determining working length when compared with Just II and Schick direct digital radiography.

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OBJECTIVE: The goal of this study was to evaluate the infection control measures actually implemented by dental surgeons during dental practice, as patients and professionals are exposed to high biological risk in dental care environments. METHOD: 614 questionnaires (90.69 percent) were answered by professionals registered in updating or in post-graduate courses in the Municipality of São Paulo. RESULTS: Out of surveyed professionals 30.62 percent admitted that surface protection barriers were not used, whereas 34.17 percent were using non ideal or outdated pre-disinfection practices. The autoclave was used by 69.38 percent of participants, although 33.80 percent were not monitoring control of the sterilization cycles. Chemical and biological indicators were not used simultaneously by 83.21 percent of respondents and were not employed on a daily or weekly basis by at least 81.75 percent. Dubious methods of sterilization were cited by 44.77 percent. Occupational accidents caused by cutting and piercing objects were reported by 47.88 percent; however, the biologic risk was underestimated by 74.15 percent of the professionals who suffered the accidents. Irritant solutions were used as an antiseptic agent by 18.55 percent. CONCLUSIONS: Infection control measures reported by dental surgeons during their practices are deficient. It is necessary to educate, raise awareness of professionals, and promote constant updating courses on procedures which aim at improving safety of dental care.

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The present study compared the accuracy of three electronic apex locators (EALs) - Elements Diagnostic®, Root ZX® and Apex DSP® - in the presence of different irrigating solutions (0.9% saline solution and 1% sodium hypochlorite). The electronic measurements were carried out by three examiners, using twenty extracted human permanent maxillary central incisors. A size 10 K file was introduced into the root canals until reaching the 0.0 mark, and was subsequently retracted to the 1.0 mark. The gold standard (GS) measurement was obtained by combining visual and radiographic methods, and was set 1 mm short of the apical foramen. Electronic length values closer to the GS (± 0.5 mm) were considered as accurate measures. Intraclass correlation coefficients (ICCs) were used to verify inter-examiner agreement. The comparison among the EALs was performed using the McNemar and Kruskal-Wallis tests (p < 0.05). The ICCs were generally high, ranging from 0.8859 to 0.9657. Similar results were observed for the percentage of electronic measurements closer to the GS obtained with the Elements Diagnostic® and the Root ZX® EALs (p > 0.05), independent of the irrigating solutions used. The measurements taken with these two EALs were more accurate than those taken with Apex DSP®, regardless of the irrigating solution used (p < 0.05). It was concluded that Elements Diagnostic® and Root ZX® apex locators are able to locate the cementum-dentine junction more precisely than Apex DSP®. The presence of irrigating solutions does not interfere with the performance of the EALs.

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The present study compared the accuracy of three electronic apex locators (EALs) - Elements Diagnostic®, Root ZX® and Apex DSP® - in the presence of different irrigating solutions (0.9 percent saline solution and 1 percent sodium hypochlorite). The electronic measurements were carried out by three examiners, using twenty extracted human permanent maxillary central incisors. A size 10 K file was introduced into the root canals until reaching the 0.0 mark, and was subsequently retracted to the 1.0 mark. The gold standard (GS) measurement was obtained by combining visual and radiographic methods, and was set 1 mm short of the apical foramen. Electronic length values closer to the GS (± 0.5 mm) were considered as accurate measures. Intraclass correlation coefficients (ICCs) were used to verify inter-examiner agreement. The comparison among the EALs was performed using the McNemar and Kruskal-Wallis tests (p < 0.05). The ICCs were generally high, ranging from 0.8859 to 0.9657. Similar results were observed for the percentage of electronic measurements closer to the GS obtained with the Elements Diagnostic® and the Root ZX® EALs (p > 0.05), independent of the irrigating solutions used. The measurements taken with these two EALs were more accurate than those taken with Apex DSP®, regardless of the irrigating solution used (p < 0.05). It was concluded that Elements Diagnostic® and Root ZX® apex locators are able to locate the cementum-dentine junction more precisely than Apex DSP®. The presence of irrigating solutions does not interfere with the performance of the EALs.

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Objetivo - Este estudo avaliou in vivo a biocompatibilidade dos cimentos AH Plus, Acroseal e EndoREZ, após a implantação em tecido subcutâneo de 16 ratos Wistar. Métodos - Os cimentos foram colocados no interior de tubos de polietileno e implantados em locais específicos no subcutâneo do dorso dos animais. Os blocos de tecidos foram removidos após 24 horas, 72 horas, 7 dias e 21 dias, processados histologicamente e analisados através da observação microscópica óptica. Resultados - Os resultados indicaram que todos os cimentos induziram reações inflamatórias discretas, que diminuíram ao longo do experimento. Conclusões - O cimento Acroseal apresentou o melhor comportamento biológico, seguido pelo AH Plus e EndoREZ.

Objective - The purpose of this study was evaluate in vivo the biocompatibility of the cements AH Plus, Acroseal and EndoREZ, after implantation in connective tissue of sixteen Wistar rats. Methods - The cements were put in the polyethilene tubs and implanted in specific areas in animal's dorsal subcutaneous. The block of tissues was removed after 24 hours, 72 hours, 7 days and 21 days, histological processes was conducted and analyzed under optical microscopic observation. Results - The results indicated that all cements induced mild inflammatory reaction, that decreased with the experiment time. Conclusions - The Acroseal cement showed the best biological reaction, followed by AH Plus and EndoREZ.

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OBJECTIVE: To evaluate the influence of 810-nm-diode laser irradiation, applied before root canal filling, on apical sealing ability of three different resin-based sealers (AH Plus, EndoRez, and RealSeal). BACKGROUND: Lasers have been widely used in endodontics. The dentin wall changes caused by laser irradiation could improve the sealing ability of endodontic cements. METHODS: Sixty single-rooted human teeth were divided into six groups, according to the endodontic sealer used and previous 810-nm-diode laser irradiation. The protocol for laser irradiation was 2.5 W in a continuous wave, in scanning mode, with four irradiations per tooth. After sample preparation, they were analyzed according to apical leakage with silver nitrate impregnation. RESULTS: The RealSeal sealer achieved minimum leakage rates (1.24 mm), with significant differences at the 1% level (Tukey's test, p<0.01) from AH Plus (1.84 mm) in nonirradiated groups. When the laser was used, there were also significant differences at the 5% level (p<0.05) between irradiated groups (1.31 and 1.78 mm, respectively). CONCLUSION: The 810-nm-diode laser irradiation did not promote significant differences in apical leakage.

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OBJECTIVE: To verify the effects of laser energy on intracanal dentin surfaces, by analyzing the morphologic changes and removal of debris in the apical third of 30 extracted human teeth, prepared and irradiated with the Nd:YAG laser and diode laser. BACKGROUND DATA: Lasers have been widely used in endodontics. The morphologic changes in dentin walls caused by Nd:YAG and diode laser irradiation could improve apical seals and cleanliness. MATERIALS AND METHODS: The protocol used for Nd:YAG laser irradiation was 1.5 W, 100 mJ, and 15 Hz, in pulsed mode, and for diode laser was 2.5 W in continuous mode. Each specimen was irradiated four times at a speed of 2 mm/sec with a 20-sec interval between applications. Five calibrated examiners scored the morphologic changes and debris removal on a 4-point scale. RESULTS: In analyzing the scores, there were no statistically significant differences between the two types of laser for either parameter, according to Kruskal-Wallis testing at p = 0.05. The SEM images showed fusion and resolidification of the dentin surface, with partial removal of debris on the specimens irradiated with the Nd:YAG laser and the diode laser, compared with controls. CONCLUSION: Both lasers promote morphologic changes and debris removal. These alterations of the dentin surface appeared to be more evident in the Nd:YAG laser group, but the diode laser group showed more uniform changes.

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