Unprepared areas and centralization of oval canals prepared with WaveOne Gold or XP-endo Shaper: microcomputed tomographic analyses / Areas não preparadas e centralização de canais ovais preparados com WaveOne Gold ou XP-endo Shaper: análises tomográficas microcomputadorizadas

ABSTRACT Current instrumentation systems cannot fully prepare oval root canal systems. This may cause accumulation of hard tissue debris and fail to eliminate bacteria from areas inaccessible to instrumentation, which could perpetuate periapical inflammation and jeopardize the success of endodontic treatment Aim To evaluate the performance of two endodontic systems in oval canals by investigating the changes in volume, unprepared areas, and centering ability of XP-endo Shaper (XPS) and WaveOne Gold (WOG) in oval canals using microcomputed tomography (micro-CT) Materials and Method Thirty mandibular canines were scanned before and after preparation with WOG (25/.07 and 35/.06) or XPS (30/.01) to evaluate the volume, surface area, and canal centralization at 4 mm and 10 mm from the apical foramen Results Volume and surface area increased significantly after preparation with both systems (p<0.05). However, no significant difference was observed in the unprepared areas, regarding either the entire canal (26.21% for WOG and 30.10% for XPS), or the apical segment (18.82% for WOG and 14.63% for XPS) (p >0.05) Conclusions Both systems maintained canal centralization, with no difference between them. XPS and WOG had similar shaping abilities in the mandibular canine, but left almost one third of the unprepared areas.

RESUMO Os sistemas de instrumentação atuais são incapazes de preparar completamente os sistemas de canais radiculares do canal oval, o que pode levar ao acúmulo de detritos de tecido duro e manter micro-organismos em áreas inacessíveis à instrumentação. Essas bactérias poderiam perpetuar a inflamação periapical e comprometer o sucesso do tratamento endodôntico Objetivo Para avaliar o comportamento de dois sistemas endodônticos em canais ovais, esse estudo investigou as alterações no volume, áreas não preparadas e capacidade de centralização do XP-endo Shaper (XPS) e do WaveOne Gold (WOG) em canais ovais usando microtomografia computadorizada (micro-CT) Material e métodos Trinta caninos inferiores foram escaneados antes e depois do preparo com WOG (25/.07 e 35/.06) ou XPS (30/.01) para avaliar o volume, a área de superfície e a centralização do canal a 4 mm e 10 mm do forame apical Resultados O volume e a área de superfície aumentaram significativamente após o preparo com ambos os sistemas (p<0,05). No entanto, não foram observadas diferenças significativas nas áreas não preparadas, não apenas em todo o canal (26,21% para WOG e 30,10% para XPS), mas também no segmento apical (18,82% para WOG e 14,63% para XPS) (p >0,05) Conclusão Ambos os sistemas mantiveram a centralização do canal, sem diferenças entre eles. O XPS e o WOG tiveram habilidades de modelagem semelhantes no canino mandibular, mas deixaram quase um terço das áreas do canal sem preparo.

Internal morphology of distal roots of mandibular first molars revealed by computed microtomography.

To evaluate the internal morphology of 100 distal roots of mandibular first molars using micro-CT. Teeth were scanned to characterise: Vertucci type, root length, canal shape, presence and location of accessory canals, and the number of foramina at 4 mm from the apex, presence of root isthmus and the length from the primary canal to the apical foramen. Vertucci type I was found in 57% of cases, followed by V (27%). The most common cross-section 1 mm from the apex was oval (49%) and circular (38%). The average root length was 16.06 mm (16.61-19.02 mm). The mean foramen size was 0.32 and 0.53 mm for the minor and major diameters, respectively. The volume, surface area and SMI were 7.84 mm3 , 68.87 mm2 and 1.52 mm, respectively. Root isthmi were found in 47% of the samples, and the length mean from the primary canal to the apical foramen was 2,03 mm. The internal morphology of the distal roots of mandibular first molars may be complex and shows variations.

Unprepared areas and centralization of oval canals prepared with WaveOne Gold or XP-endo Shaper: microcomputed tomographic analyses.

Current instrumentation systems cannot fully prepare oval root canal systems. This may cause accumulation of hard tissue debris and fail to eliminate bacteria from areas inaccessible to instrumentation, which could perpetuate periapical inflammation and jeopardize the success of endodontic treatment. Aim: To evaluate the performance of two endodontic systems in oval canals by investigating the changes in volume, unprepared areas, and centering ability of XP-endo Shaper (XPS) and WaveOne Gold (WOG) in oval canals using microcomputed tomography (micro-CT). Materials and Method: Thirty mandibular canines were scanned before and after preparation with WOG (25/.07 and 35/.06) or XPS (30/.01) to evaluate the volume, surface area, and canal centralization at 4 mm and 10 mm from the apical foramen. Results: Volume and surface area increased significantly after preparation with both systems (p<0.05). However, no significant difference was observed in the unprepared areas, regarding either the entire canal (26.21% for WOG and 30.10% for XPS), or the apical segment (18.82% for WOG and 14.63% for XPS) (p >0.05). Conclusions: Both systems maintained canal centralization, with no difference between them. XPS and WOG had similar shaping abilities in the mandibular canine, but left almost one third of the unprepared areas.

Os sistemas de instrumentação atuais são incapazes de preparar completamente os sistemas de canais radiculares do canal oval, o que pode levar ao acúmulo de detritos de tecido duro e manter micro-organismos em áreas inacessíveis à instrumentação. Essas bactérias poderiam perpetuar a inflamação periapical e comprometer o sucesso do tratamento endodôntico. Objetivo: Para avaliar o comportamento de dois sistemas endodônticos em canais ovais, esse estudo investigou as alterações no volume, áreas não preparadas e capacidade de centralização do XP-endo Shaper (XPS) e do WaveOne Gold (WOG) em canais ovais usando microtomografia computadorizada (micro-CT). Material e métodos: Trinta caninos inferiores foram escaneados antes e depois do preparo com WOG (25/.07 e 35/.06) ou XPS (30/.01) para avaliar o volume, a área de superfície e a centralização do canal a 4 mm e 10 mm do forame apical. Resultados: O volume e a área de superfície aumentaram significativamente após o preparo com ambos os sistemas (p<0,05). No entanto, não foram observadas diferenças significativas nas áreas não preparadas, não apenas em todo o canal (26,21% para WOG e 30,10% para XPS), mas também no segmento apical (18,82% para WOG e 14,63% para XPS) (p >0,05). Conclusão: Ambos os sistemas mantiveram a centralização do canal, sem diferenças entre eles. O XPS e o WOG tiveram habilidades de modelagem semelhantes no canino mandibular, mas deixaram quase um terço das áreas do canal sem preparo.

Microtomographic Evaluation of Canal Centralization and Dentine Removal after Canal Preparation with Two Rotary Systems: HyFlex EDM and ProTaper Next.

OBJECTIVE: This study compared the ProTaper Next (PTN; Dentsply Sirona, Tulsa, Oklahoma, United States) and HyFlex EDM (HEDM; Coltene/Whaledent AG, Alstätten, Switzerland) systems using micro-computed tomography (CT). MATERIALS AND METHODS: Twenty-one mesial roots classified as Vertucci's type IV from extracted mandibular first molars with curvatures between 20 and 40 degrees were selected. The teeth were scanned using a micro-CT before and after root canal preparation by both systems, applied to the same root, in alternating canals. The following parameters were analyzed: canal centering, apical transportation, root canal diameter/root diameter. RESULTS: No statistically significant differences between both systems were observed for any of the assessed morphological parameters (p > 0.05). All canals presented diameter enlargement of more than 40% in relation to root diameter in the cervical and middle segments. No statistically significant difference was noted between the HEDM and PTN groups. The wear percentage for the HEDM group in the cervical and middle thirds were 49.66 ± 8.65 and 46.48 ± 14.29, respectively, and 51.02 ± 11.81 and 45.48 ± 10.79 for the PTN group, respectively. CONCLUSION: Both systems displayed similar mandibular molar mesial canals preparation, with no differences noted for any of the assessed parameters. Both groups showed increased canal diameter in the cervical and middle thirds by more than 40%.