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A palatogingival groove is a developmental anomaly that predisposes the involved tooth to develop a severe periodontal lesion. These grooves often present a clinical challenge because diagnosis and treatment planning require an interdisciplinary approach. This case report describes the successful management of a right maxillary lateral incisor with a deep palatogingival groove in combination with an extensive periodontal pocket and pulp necrosis of the involved tooth. Collaborative management used a combination of endodontic treatment, periodontal therapy, odontoplasty, and a periodontal regenerative procedure using protein complex derived from enamel matrix (Emdogain; Straumann, Basel, Switzerland). Despite a predicted poor prognosis, the tooth lesion healed. This report also discusses the rationale behind the treatment modalities. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: Complete endodontic system disinfection requires the removal of vital and necrotic pulp tissue, microorganisms, and toxins. The purpose of this study was to compare the effects of 2 ultrasonic irrigation techniques on the penetration of sodium hypochlorite into the main canal and simulated lateral canals of extracted teeth. Methods: Two simulated lateral canals each were created 2, 4, and 6 mm from the working length in 60 single-rooted teeth (6 canals/tooth, n = 360). To resemble the clinical situation, a closed system was created in each tooth. The teeth were randomly assigned to 3 experimental irrigation groups: group 1 (n = 20), positive pressure irrigation (PPI); group 2 (n = 20), passive ultrasonic irrigation (PUI); and group 3 (n = 20), continuous ultrasonic irrigation (CUI). Samples were evaluated by direct observation of still images recorded under a dental operating microscope. To examine irrigating solution penetration, 20% Chinese ink (Sanford Rotring GmbH, Hamburg, Germany) was added to a 5% sodium hypochlorite solution and delivered into the root canals. Results: The results showed a significantly higher (P < .05) penetration of irrigant into the lateral canals in the CUI group. PUI and CUI did not differ significantly in solution penetration into the apical thirds of the main canals. The PPI group showed a significantly lower penetration of sodium hypochlorite into the main and lateral canals compared with the CUI and PUI groups. Conclusions: CUI as a final rinse significantly increased the penetration of irrigating solution into simulated lateral canals. [Copyright &y& Elsevier]

The difficulty of eliminating Enterococcus faecalis and other bacteria infecting dental root canals makes it desirable to develop formulations capable of sustained release of antibiotics within the canal. With this function in view, in this work we compared the mechanical, drug release and biocompatibility properties of amoxicillin-loaded collagen (CL) and CL complexed with poly[(methyl vinyl ether)-co-(maleic anhydride)] (PVMMA), with or without glutaraldehyde (GTA) or the natural product genipin (GN) as cross-linker. Collagen was not denatured by complexation with PVMMA. Only CL-PVMMA-GN sponges did not disintegrate during 7 days exposure to cell culture medium (un-cross-linked CL disintegrated within 24 h and un-cross-linked CL-PVMMA within 4 days), and CL-PVMMA-GN sponges also exhibited the most appropriate combination of mechanical properties (hardness, modulus of deformability and plasticity). CL-PVMMA-GN sponges absorbed aqueous medium faster than other cross-linked formulations, but their maximum uptake was less; and drug release from CL-PVMMA-GN sponges tended to be faster than from any other, except un-cross-linked CL-PVMMA, maximum release taking about 4 days. No formulation significantly altered the viability of L929 fibroblast-like mouse connective tissue cells, but cells growing on sponges showed signs of non-adherence. It is concluded that genipin-cross-linked CL-PVMMA sponges merit further investigation as antibiotics vehicles and aids to tissue regeneration in the dental root canal. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: This in vitro study compared the tooth color and the ultrastructure of internal dental tissues before and after internal bleaching. Methods: Sodium perborate was placed in the pulp chamber of endodontically treated molars and sealed with intermediate restorative material. The test samples were stored in a physiologic solution, and the bleaching agent was replaced every 7 days. A control group was used. After 1 month, the colors of the test and control samples were measured with a colorimeter, and the internal surfaces were observed under field emission scanning electron microscopy (FESEM). Results: Statistically significant differences were found between the test and control sample colors. The FESEM ultrastructure analysis of the internal enamel and dentin surfaces did not show any changes after the internal bleaching. Conclusions: The results of the present study show that sodium perborate is effective in bleaching nonvital teeth and does not produce ultrastructural changes in the dental tissues. [Copyright &y& Elsevier]

summary It is difficult to determine the existence of a normal or physiological masticatory cycle, because there exists great individual diversity. This study presents some data about two parameters of masticatory cycles according to the frontal plane, i.e. the area and length of right-sided and left-sided cycles in a group of 30 young people, 18 women and 12 men. For our study the Myotronics K6-1 kinesiograph was used. It registers the magnetic field and allows us to obtain graphic recordings of the jaw movement in the three space planes. Other authors have analysed these parameters, but none of those reviewed provides information about the distribution to each side or according to the gender of sampling subjects selected for the analysis. We have tried to describe the normal morphology of the masticatory cycles and, also, establish a reference so as to provide help in the diagnosis of the functional pathology of the masticatory system. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: Rotary nickel-titanium instruments have multiple advantages but with the risk of more fractures because of flexure or torsion. Alternating rotation appears to be an alternative to continuous rotary movement. The objective of this study was to determine the influence of the type of instrument rotation on the frequency of fractures or deformation. Methods: Instrumentation was performed on 120 molar root canals with an angle of curvature greater than 30° using alternating rotation (group A: 60° clockwise, 45° counterclockwise) and continuous rotation (group B). Results: The results indicate that instruments used with alternating rotation have a higher mean number of uses (13.0) compared with the continuous rotation group (10.05); this difference was statistically significant (p < 0.05). Conclusions: The ProTaper shaping instruments (S1 and S2) are those that achieved the greatest difference in use with alternating rotation, with S2 being the most resistant to fracture or deformation with the two types of movement used. [Copyright &y& Elsevier]