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Aim: This study evaluated the efficiency and effectiveness of three glass fiber post removal techniques. Materials and Methods: Forty-five extracted maxillary teeth were endodontically treated and cross-sectioned in thirds. Presence of cementing agent and dental structure wear were assessed by analyzing images taken before luting of glass fiber post and after removal procedure. Teeth were divided into 3 groups: Group 1 - diamond bur + Largo reamer; Group 2 - ultrasonic insert; Group 3 - carbide bur + ultrasonic insert. Time spent on removal procedures, dental structure wear and amount of remaining cement agent were recorded and results submitted to ANOVA, Kruskal Wallis and Tukey-Kramer tests. Results: Group 1 - 16'46", 33.33% and 6.99%; Group 2 - 12'31", 40% and 7.86%; and Group 3 - 10'24", 80% and 8.14%. Group 3 presented the most effective removal of glass fiber posts. Conclusion: There was no significant difference in efficiency among the evaluated techniques.
Subject(s)
Dental Materials/chemistry , Endodontics/methods , Glass , Humans , Maxilla , /methods , Tooth Extraction/methods , Tooth Wear/analysis , UltrasonicsABSTRACT
Objective: Use computed tomography to compare three methods of root canal instrumentation. Methods: Thirty mandibular molar mesiobuccal canals were divided in three groups according to instrumentation technique: Group 1 - hand instrumentation with balanced force technique; Group 2 - Protaper Universal rotary system following manufacturer's instructions; and Group 3 - Protaper Universal rotary system and Gates-Glidden drills. Teeth were evaluated by computed tomography before and after preparation at three axial cuts: 3mm, 5mm, and 7mm from the root apex. Data were subjected to statistical analysis using the F, Chi-Square, Likelihood Ratio Chi-Square, and Mantel-Haenszel Chi-Square tests. Results: Group 3 showed significantly greater dentin removal with no tendency towards mesial or distal canal transportation, compared with Groups 1 and 2. Also, Group 3 required the least amount of time for instrumentation. Conclusion: Association of rotary instrumentation and Gates-Glidden drills is a safe and effective technique for root canal preparation.
Objetivo: Comparar o preparo de canais radiculares através de tomografia computadorizada. Métodos: Trinta canais mésio-vestibulares de molares inferiores foram divididos em 3 grupos, de acordo com a técnica de instrumentação a ser utilizada: Grupo 1 - instrumentação manual, utilizando-se de movimentos de forças balanceadas; Grupo 2 - Sistema Protaper Universal de instrumentação rotatória, conforme protocolo do fabricante; Grupo 3 - Sistema Protaper Universal de instrumentação rotatória associada a brocas de Gates- Glidden para pré-alargamento cervical. Os dentes foram submetidos à tomografia computadorizada antes e após o preparo, e a análise das imagens foi feita através de cortes axiais a 3mm, 5mm e 7mm do ápice radicular. Os dados foram submetidos a análise estatística utilizando testes paramétricos (para as variáveis tempo e desgaste de dentina) e não-paramétricos (para a variável sentido do desvio). Resultados: Os resultados mostraram uma tendência significativa do grupo 3 a desgastar mais dentina quando comparado aos grupos 1 e 2. O grupo 1 desgastou significantemente mais dentina para o sentido distal e o grupo 2 desgastou significantemente mais para o sentido mesial. O grupo 3 não apresentou tendência de sentido de desgaste. O tempo despendido foi menor no grupo 3, seguido pelo grupo 1 e 2. Conclusão: Pôde-se concluir que a associação das brocas de Gates-Glidden ao Sistema Protaper Universal promoveu um preparo adequado de maneira segura e, a tomografia computadorizada foi um método adequado para a análise do preparo de canais radiculares.
ABSTRACT
Introduction: Several rotary systems have been evaluated for removal of endodontic filling materials from the canal. Moreover, studies focusing on the comparison of the effectiveness of rotary systems versus hand instrumentation have yielded mixed results in terms of the efficacy and amount of time required by each technique. Objective: To compare the effectiveness of a nickel-titanium rotary system and of hand instrumentation using stainless steel files and Gates-Glidden burs in the removal of gutta-percha from root canals, as well as the time required to complete the procedure by each method. Material and methods: Forty single-rooted teeth were prepared and obturated then divided in two groups, according to the method employed for removal of the gutta-percha: ProTaper Universal rotary retreatment system (rotary instrumentation) and stainless steel hand files with Gates-Glidden burs (hand instrumentation). The time required to remove gutta-percha by each method was recorded. Roots were then sectioned lengthwise and the apical, middle, and coronal thirds were analyzed by SEM under two magnifications: x400 and x1,000. Results: Rotary instrumentation promoted better cleansing compared with hand instrumentation. The apical third was less clean than the coronal and middle thirds (Kruskal-Wallis p < 0.05). Rotary instrumentation was faster than hand instrumentation (Tukey p < 0.05). Conclusion: Although none of the methods promoted complete cleanliness of the canal walls, ProTaper Universal system showed better results and was faster than hand instrumentation.
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Introduction and Objective: Endodontic failure can be associated to well-conducted treatments due to microbial factors characterized by intra or extraradicular infections not eliminated during endodontic treatment. Case report: This report describes a case of persistent apical periodontitis of an asymptomatic maxillary lateral incisor endodontically retreated and subsequently subject to apical surgery. Conclusion: After SEM morphological analysis of the apical fragment, areas of cementum-dentin resorption that were probably responsible for the perpetuation of the disease process were observed.