Ultrastructural analysis of root canal dentine irradiated with 980-nm diode laser energy at different parameters.

OBJECTIVE: The purpose of this in vitro study was to investigate using the scanning electron microscope (SEM) the ultrastructural morphological changes of the radicular dentine surface after irradiation with 980-nm diode laser energy at different parameters and angles of incidence. BACKGROUND DATA: There have been limited reports on the effects of diode laser irradiation at 980 nm on radicular dentin morphology. MATERIALS AND METHODS: Seventy-two maxillary canines were sectioned and roots were biomechanically prepared using K3 rotary instruments. The teeth were irrigated with 2 mL of distilled water between files and final irrigation was performed with 10 mL of distilled water. The teeth were then randomly divided into five groups (n = 8 each) according to their diode laser parameters: Group 1: no irradiation (control); group 2: 1.5 W/continuous wave (CW) emission (the manufacturer's parameters); group 3: 1.5 W/100 Hz; group 4: 3 W/CW; and group 5: 3 W/100 Hz. Laser energy was applied with helicoid movements (parallel to the canal walls) for 20 sec. Eight additional teeth for each group were endodontically prepared and split longitudinally and irradiation was applied perpendicularly to the root surface. RESULTS: Statistical analysis showed no difference between the root canal thirds irradiated with the 980-nm diode laser, and similar results between the parameters 1.5 W/CW and 3 W/100 Hz (p > 0.05). CONCLUSION: When considering different output powers and delivery modes our results showed that changes varied from smear layer removal to dentine fusion.

Medidas de prevenção pré e pós-exposição a acidentes perfurocortantes na prática odontológica / Pre and post-exposure preventive measures to injuries caused by percutaneous instruments during dental practice

Objetivos: O objetivo deste estudo foi determinar a prevalência de acidentes com instrumentos perfurocortantes entre odontólogos, verificar o grau de utilização de equipamentos de proteção individual (EPI) e a atitude tomada frente aos acidentes ocorridos. Metodologia: A amostra foi composta por cirurgiões-dentistas, que atuam no Estado de Santa Catarina e que freqüentaram cursos de atualização profissional na UFSC em 2005. Os dados foram coletados através de questionário semi-estruturado auto-aplicável sobre informações gerais de prevenção, utilização de EPI e ocorrência de acidentes. Resultados: Dos 80 profissionais que responderam ao questionário 73% já haviam sofrido pelo menos um acidente. A prevalência de uso rotineiro de EPI foi: luvas e máscaras (100%); óculos (96%); jaleco (97%); gorro (52%); isolamento absoluto (56%) e sobre luva (1%). A falta de uso de EPI não foi citada como principal responsável pelos acidentes, mas sim, a falta de atenção (71%) e a pressa (30%) durante os procedimentos clínicos. Apenas 22% dos entrevistados com acidentes submeteram-se às medidas de prevenção pós-exposição; a maioria limitou-se a lavar o local afetado (69%). Os materiais e instrumentais que mais causaram acidentes foram: brocas, agulhas anestésicas, curetas, alavancas, lâminas de bisturi e limas de endodontia. Conclusão: Este estudo sugere que existe necessidade de maior orientação quanto a medidas adicionais de prevenção e da correta atitude a ser tomada diante da ocorrência de acidentes.

Purpose: The aim of this study was to determine the prevalence of injuries caused by percutaneous instruments among dentists, verify the use of equipment for individual protection (EPI) and the measures taken after the accident. Methods: The sample was composed by dentists, who worked in Santa Catarina state and attended continuing education courses at UFSC in 2005. Data were collected by means of a self-applied and semi-structured questionnaire on general information about prevention, use of EPI, and occurrence of accidents. Results: Eighty dentists answered the questionnaire and 73% had at least one accident. The prevalence of routine use of EPI was: disposable gloves and masks (100%); eyeglasses (96%); gowns (97%); caps (52%), and rubber dam (56%). Omission of EPI use was not the main reason for accidents, but lack of attention (71%) and hurry (35%) were mostly cited. Only 22% of dentists were submitted to post-exposure preventive measures after accidents; most dentists only washed the injury (69%). The materials and instruments mostly reported as the cause of accidents were: drills, needles, curettes, root elevators, knife blades, and endodontic files. Conclusion: This study suggests that it is necessary to improve the orientation and awareness of dentists on the correct post-exposure management of injuries caused by percutaneous instruments.