The objective of this study was to evaluate periapical and apical repair using calcium hydroxide root canal dressings for different lengths of times in teeth with induced chronic periapical lesions. A total of 61 root canals of maxillary and mandibular premolars from 4 dogs were used. After mechanical preparation of the root canals using the crown-down technique, and 5.25% NaOCl as irrigating s...

M axillary canines and incisors often lack an adequate cingulum to allow for a conventional cingulum rest preparation (Fig. 1). Cingulum rests on mandibular canines have often not been used because of the perception that there is not adequate thickness of enamel in the rest region. This has recently been refuted in research by Rossi,’ who found that if the rest seats are prepared on mandibular ...

Dilaceration is the result of a developmental anomaly in which there has been an abrupt change in the axial inclination between the crown and the root of a tooth, but the criteria in the literature for recognizing root dilaceration vary. Two possible causes of dilaceration are trauma and developmental disturbances, and it has also been proposed that it might be associated with some developmenta...

The number of synthetic methods enabling the preparation of ammonium-based rotaxanes has increased very rapidly in the past ten years. The challenge in the synthesis of rotaxanes results from the rather weak interactions between the ammonium-containing rod and the crown ether macrocycle in the pseudorotaxane structure that rely mostly on O*H hydrogen bonds. Indeed, no strong base or polar solve...

background and aims. during root canal preparation, debris extruded beyond the apical foramen may result in periapical inflammation and postoperative pain. to date no root canal preparation method has been developed that extrudes no periapical debris. the purpose of this study was to identify a system leading to minimal extrusion of debris from the apical foramen. the study was conducted to com...

BACKGROUND The main reason for the failure of endodontic therapy is the incomplete knowledge about the anatomical variation of root canals. One of the most important factors that leads to the failure of root canal treatment, is missed and untreated major root canals. OBJECTIVE with respect to the complexity of mandibular incisors treatment and high prevalence of the second canal, and the poss...