Retrograde root canal retreatment with pre-bent ultrasonic files. A retrospective outcome study.

AIM: To assess retrospectively the clinical and radiographic outcomes of retrograde root canal retreatment (RRR) and to identify possible prognostic factors that may affect the outcome. METHODOLOGY: Clinical records and radiographs were collected from patients who had undergone RRR between 2009 and 2016 and had a 1-year follow-up. All surgical procedures were performed by a single endodontist. The RRR technique involved minimal root-end resection and maximal length retrograde preparation using pre-bent ultrasonic files. Outcomes were categorized as complete, incomplete, uncertain or unsatisfactory healing based on clinical and radiographic findings. The complete and incomplete healing cases were pooled and considered as successes, while uncertain and unsatisfactory cases were considered failures. Prognostic factors were analysed using univariate analysis and multivariate logistic regression. RESULTS: In total, 575 patients with 721 teeth were included. The overall success rate was 91.8%. None of the prognostic factors (including age, gender, size of periapical radiolucency and isthmus presence) had a significant influence on the outcome (P > 0.05). Univariate analysis revealed tooth type had a significant influence on outcome (P = 0.008) with mandibular incisors having a significantly lower success rate (71.4%). Multivariate analysis using logistic regression revealed that the only variable with a significant association to the outcome was retrograde preparation length (P = 0.016, odds ratio = 1.299 (1.050, 1.607), C.I. = 95%)), i.e. the longer the retrograde preparation, the better the outcome. CONCLUSIONS: Retrograde root canal retreatment was successful in 91.8% of cases. This predictable success rate was achieved while minimizing root-end resection and maximizing retrograde canal preparation length.

Efficacy of XP-endo finisher files in the removal of calcium hydroxide paste from artificial standardized grooves in the apical third of oval root canals.

AIM: To compare the efficacy of the XP-endo finisher file (XP) (FKG Dentaire, La Chaux de Fonds, Switzerland) to that of passive ultrasonic irrigation (PUI) and conventional syringe and needle irrigation (SNI) in the removal of calcium hydroxide paste from an artificial standardized groove in the apical third of root canals. METHODOLOGY: The root canals of 68 mandibular incisors with single oval canals were prepared using Mtwo instruments (VDW GmbH, Munich, Germany) up to size 40, .04 taper. Each tooth was split longitudinally, and in one half of the root, a standardized groove was prepared in the apical part of the specimen. The grooves were filled with Ca(OH)2 , and the root halves were reassembled. The roots were randomly divided into two control groups (n = 4) and three experimental groups (n = 20) according to the Ca(OH)2 methods used: XP, PUI and SNI. The amount of remaining medicament was evaluated under X25 magnification using a 4-grade scoring system. Kappa values were calculated for intra- and interobserver agreement evaluation. The differences in the Ca(OH)2 scores amongst the different groups were analysed using the Kruskal-Wallis test. RESULTS: None of the tested methods could completely clean the Ca(OH)2 from the artificial standardized groove in the apical third of the root canals. XP and PUI removed significantly more Ca(OH)2 than SNI (P < 0.001), with no significant differences between them (P = 0.238). CONCLUSIONS: XP and PUI were more effective in removing Ca(OH)2 from artificial standardized grooves in the apical third of root canals than SNI.

[Decoronation: treatment protocol for ankylotic root resorption as a consequence of dental trauma].

Severe dental traumatic injuries, such as the complete displacement of a tooth from its socket (Avulsion) or the displacement of a tooth within its socket (Intrusive Luxation), may result in extensive injury to the root surface. As a result, the root surface injury heals without cementum and there is fusion between the alveolar bone and the exposed dentin or anorganic exposed cementum, without any attachment apparatus between them. This phenomenon is known as "dento-alveolar ankylosis" and is accompanied by ankylotic resorption of the root. In a process that results subsequent to the ankylosis, the root surface resorbs, and this is part of the remodeling of the alveolar bone (ankylotic resorption). When the traumatic injury occurs at a young age, lateral and apical growth of the alveolar bone continues without continued physiological eruption of the tooth. As a result, the position of the ankylotic tooth does not change, and with time thetooth appears infra-occluded resulting in severe esthetic and functional consequences. Extraction of the ankylotic tooth is difficult and sometimes even impossible due to the rigid fusion between the bone and the tooth. In addition, attempted extraction of the ankylotic tooth may lead to fracture of the buccal plate and resorption of the alveolar bone. Retention of the ankylotic tooth may lead to damage in bone deposition in the verticaldimension, leading to difficulties in future prosthodonticrehabilitation, research-based information has been incorporated

[Revascularization: a new treatment method in endodontics].

Recently a number of published articles concerning a new treatment method in traumatized young permanent teeth with a wide open apex that have lost vitality, with or without periapical lesions have shown success. This new treatment is entitled "Revascularization" and its aim is to promote root maturation in infected immature teeth with open apices. This procedure stimulates the formation of hard tissue as well as elongation and thickening of the dentinal walls and closure of the root apex. Sometimes the vitality of the teeth is regained. The aim of the present publication is to describe the revascularization technique and to clarify the indications of its use.