Shaping Ability of ProTaper Next, WaveOne, and Reciproc in Simulated Root Canals.

INTRODUCTION: The study aimed to compare the shaping and preservation of the original curvature of simulated curved root canals using the following instruments: Reciproc (Rcp), WaveOne (Wo), and the ProTaper Next system (Ptn). MATERIALS AND METHODS: A total of 45 resin blocks with simulated curved root canals were divided into three groups (n = 15), prepared using the Rcp (R25), Wo (25/0.8), and Ptn (X2) instruments. Standardized photographs were taken before and after canal instrumentation. After the superimposition of the images, the amount of resin removed from the curvature's inner and outer walls was measured at six apical levels, at intervals of 1 mm. The canals' angles of curvature before and after instrumentation were subtracted. RESULTS: There were no significant differences between the instruments in terms of the total amount of resin removed of the inner or outer walls of the apical curvature (p > 0.05). The Rcp instruments provided the best resin removed ratios between the walls. The means of the change in angle were as follows: Wo = 2.15°, Ptn = 0.92°, and Rcp = 0.21°. WaveOne caused significantly higher deviations than Rcp. CONCLUSION: All of the instruments demonstrated a tendency to straighten the simulated root canal. Instruments that use rotary movement achieved an effect similar to that of the reciprocating instruments in relation to change in angle. CLINICAL SIGNIFICANCE: Deviations from the original shape of the root canal could have a negative impact on the quality of a filling and consequently on the success of the endodontic treatment.

Treatment of perforating internal root resorption with MTA: a case report.

Endodontic treatment of teeth with perforating internal root resorption represents a clinical challenge. In most cases, extraction of the tooth and subsequent replacement with an osseointegrated implant is indicated. Presented herein is a case report of a maxillary lateral incisor with advanced perforating internal root resorption in the middle third of the root and the presence of a sinus tract. Mineral Trioxide Aggregate (MTA) was used with the aid of a surgical microscope in order to fill the resorption area after conventional root canal therapy of the apical segment. At the follow-up after 11 years and 8 months, the patient was clinically asymptomatic and the sinus tract had disappeared. The radiographic examination and computerized tomography indicated periodontal bone repair.

Sealing ability of MTA-Angelus with propyleneglycol in furcal perforations.

This study evaluated the sealing ability of gray MTA-Angelus mixed with propyleneglycol in furcal perforations using a bacterial leakage test. Furcal perforations were created in 30 human mandibular molars using a size 3 round bur The samples were divided randomly into 2 experimental groups (n=10) according to the mixing agent. In G1, the MTA powder was mixed with propyleneglycol, while distilled water was used in G2. A 3:1 powder-liquid ratio was used for both groups. The MTA was placed in the perforation with an MTA carrier and condensed with hand pluggers. Non-repaired (n=5) and totally sealed (n=5) perforations served as positive and negative controls, respectively. Bacterial leakage was assessed daily for 30 days in a double-chamber apparatus with Enterococcus faecalis. Data were analyzed using Fisher exact test (p < 0.05) for three leakage periods: 1st to 10th day (P1); 11th to 20th day (P2); and 21st to 30th day (P3). The positive control presented leakage in all specimens within the first 24 hours, while no leakage was observed in the negative control during the experimental period. Leakage was observed in five (50%) of the 10 samples of the propyleneglycol group (G1) and seven (70%) of the distilled water group (G2) by the 20th day, without significant difference between the groups in periods P1 and P2 (p = 0.137). The leakage was significantly lower for G1 than G2 in period P3 (50% versus 100%, respectively, p = 0.016). In this single aerobic bacterial leakage method, the use of propyleneglycol as a vehicle for gray MTA-Angelus increased its sealing ability in furcal perforations at the end of the 30-day experimental period.

Sealing ability of MTA-Angelus with propyleneglycol in furcal perforations

This study evaluated the sealing ability of gray MTA-Angelus mixed with propyleneglycol in furcal perforations using a bacterial leakage test. Furcal perforations were created in 30 human mandibular molars using a size 3 round bur. The samples were divided randomly into 2 experimental groups (n=10) according to the mixing agent. In G1, the MTA powder was mixed with propyleneglycol, while distilled water was used in G2. A 3:1 powder-liquid ratio was used for both groups. The MTA was placed in the perforation with an MTA carrier and condensed with hand pluggers. Nonrepaired (n=5) and totally sealed (n=5) perforations served as positive and negative controls, respectively. Bacterial leakage was assessed daily for 30 days in a double-chamber apparatus with Enterococcus faecalis. Data were analyzed using Fisher exact test (p<0.05) for three leakage periods: 1st to 10th day (P1); 11th to 20th day (P2); and 21st to 30th day (P3). The positive control presented leakage in all specimens within the first 24 hours, while no leakage was observed in the negative control during the experimental period. Leakage was observed in five (50%) of the 10 samples of the propyleneglycol group (G1) and seven (70%) of the distilled water group (G2) by the 20th day, without significant difference between the groups in periods P1 and P2 (p=0.137). The leakage was significantly lower for G1 than G2 in period P3 (50% versus 100%, respectively, p=0.016). In this single aerobic bacterial leakage method, the use of propyleneglycol as a vehicle for gray MTAAngelus increased its sealing ability in furcal perforations at the end of the 30-day experimental period.

Este estudo avaliou a capacidade de selamento do MTA-Angelus cinza manipulado com propilenoglicol em perfuracoes de furca usando um teste de infiltracao bacteriana. Perfuracoes de furca foram criadas em 30 molares inferiores usando uma broca esferica numero 3. As amostras foram divididas aleatoriamente em dois grupos experimentais (n=10) de acordo com o agente de manipulacao. Em G1, o po do MTA foi manipulado com propilenoglicol enquanto que a agua destilado foi utilizada no G2. A proporcao po-liquido de 3:1 foi usada para ambos os grupos. O MTA foi colocado na perfuracao com uma porta- MTA e condensado com condensadores manuais. Perfuracoes nao-reparadas (n=5) e totalmente impermeabilizadas (n=5) serviram como controle positivo e negativo, respectivamente. A infiltracao bacteriana foi verificada diariamente durante 30 dias em um aparato de dupla camara com Enterococcus faecalis. Os dados foram analisados pelo teste exato de Fisher (p<0,05) para tres periodos: 1o ao 10o dia (P1), 11o ao 20o dia (P2) e do 21o ao 30o dia (P3). O controle positivo apresentou infiltracao em todas as amostras nas primeiras 24 horas, enquanto nenhuma infiltracao foi observada no controle positivo durante o periodo experimental. Infiltracao foi observada em 5 (50%) das 10 amostras do grupo do propilenoglicol (G1) e 7 (70%) do grupo da agua destilada no 20o dia, sem diferenca significativa entre o grupos nos periodos P1 e P2 (p=0,0137). A infiltracao foi significantemente menor para G1 que para G2 no periodo P3 (50% versus 100%, respectivamente, p=0,016). Neste metodo de infiltracao de apenas uma bacteria aerobica, o uso do propilenoglicol como veiculo para o MTA-Angelus cinza aumentou sua capacidade de selamento em perfuracoes de furca no final do periodo experimental de 30 dias.

Double 'pink tooth' associated with extensive internal root resorption after orthodontic treatment: a case report.

Advanced internal resorption affecting the crown of teeth may result in the appearance of a 'pink tooth', which, when located in the root canal, can perforate the external root surface. Therapeutically, this condition represents a clinical challenge and normally requires a combined endodontic and surgical focus. Presented herein are cases of double 'pink tooth' which appeared at different times after orthodontic treatment. In the most severe case, upon radiographic examination and computed tomography, the maxillary right central incisor presented an internal resorption, extending from the pulp chamber to the root middle third. After pulp removal, the debridement of the defect was performed using a 2.5% sodium hypochlorite solution, a #80 Kerr file, and an ultrasonic tip ST-17, aided by a surgical microscope. During the cleaning process, various sites of periodontal communication were identified. Upon controlling the hemorrhaging, the root canal was completely filled with White mineral trioxide aggregate. Within the 3-month follow-up treatment, a pink spot appeared on the maxillary left central incisor, which received conventional root canal therapy. Clinically and radiographically, over 18 months of follow up, both cases responded favorably to the proposed treatments. Therefore, it is important to monitor the patient due to the fact that pulp and periodontal sequelae can develop at varied moments after orthodontic treatment. Furthermore, with the current technology and biomaterials, it is possible to resolve cases with extensive internal perforating resorption through endodontic treatment.

Favorable response of an extensive periapical lesion to root canal treatment.

This article presents non-surgical resolution of an extensive periapical lesion of endodontic origin associated with the maxillary left lateral incisor. Clinical examination revealed an asymptomatic bony hard swelling confined to the palate, while radiographic analysis showed a lesion measuring 22 mm in diameter and nearly 389 mm(2) in area. Through apical patency, 4 ml of intracanal exudate was drained. After thorough biomechanical preparation, a calcium hydroxide/CPMC root canal dressing was applied and periodically renewed for 11 months. The exudate was eliminated at treatment onset and significant bone formation was observed at the periapical region in the following months with concomitant resolution of the cortical expansion. Complete radiographic resolution of the periapical lesion was observed two years after the root canal filling. Thus, non-surgical treatment of this supposedly cystic, extensive periapical lesion provided favorable clinical and radiographic response.

Negative influence of continuous wave technique on apical sealing of the root canal system with Resilon.

The aim of this study was to investigate apical microleakage after use of the Resilon system in comparison with gutta-percha. The materials used were 54 mesial roots of mandibular molars with an apical curvature of 20-40 degrees . The root canals were instrumented with the Prosystem GT(R) and obturated with: Group I: Gutta-percha + Sealer by lateral condensation (n = 25); Group II: Gutta-percha + Sealer, complemented by System B and Obtura II (n = 25); Group III: Resilon + System B and Obtura II (n = 25); Group IV: Resilon by lateral condensation (n = 25). After immersion in India ink, the specimens were demineralized and rendered transparent. Apical dye leakage was analyzed with a stereomicroscope and a digital camera connected to a computerized system. All groups showed different degrees of apical dye microleakage. The Kruskal-Wallis test revealed that the largest leakage occurred in Group I (P < 0.05), whereas the other groups presented a similar pattern of microleakage (P > 0.05). Thermoplastification negatively influenced the apical sealing ability of Resilon. Gutta-percha points and conventional sealer yielded the highest values of apical leakage, especially when the lateral condensation technique was used. Regardless of the obturation technique employed, the Resilon system provided the lowest mean values of apical leakage, but did not provide hermetic sealing of the root canal system.

Apical surgery with calcium hydroxide capping of the exposed dentine: a case report.

Among a variety of biomaterials that have been reported to be ideal for dental repair, calcium hydroxide has been shown to have excellent long-term biocompatibility in the pulp and periapical areas. Here we report an alternative method employing calcium hydroxide for periapical surgery in a patient who developed internal apical resorption after traumatic injury, which negatively affected the quality of the cleaning, shaping and filling of the root canal. Obturation of the root canal as far as the middle third was followed by apicoectomy and ultrasonic retropreparation, and then retrograde root filling with resin cement sealer (Sealer 26) and zinc oxide powder. Calcium hydroxide paste was applied over the exposed dentinal surface, forming a barrier over the root apex. Radiographic follow-up after 24 months showed absence of apical resorption and complete periapical bone repair associated with a continuous apical lamina dura.