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Apicoectomy may be considered definite treatment, however, in cases of mechanical failure such as apical blockage or perforation. Such complications may result in failure of an otherwise perfectly obturated root canal system. Surgical removal of the untreated apical portion of the root will correct the problem.
Burnishing gutta-percha is another fruitless maneuver according to Schoeffel. If you simply try to burnish the gutta-percha, you will pull it away from one wall as you burnish toward the opposite wall. Therefore, apicoectomy is merely one step toward the final objective - the retroseal.
Retroseal is the process that finally resolves most endodontic failures. Since the 1950s most clinicians have realizedthat virtually all failures result from leaking root canal systems. The often quoted Washington Study attributed root canal failures to apical percolation (63.46%), operator error (14.42%) root perforation (9.61%), calcified canals (3.85%), broken instrument (.96%), or case poor selection. Apicoectomy and retroseal can reverse all of these errors except improper case selection and some types of operator error.
It should be emphasized that endodontic surgery is not to be used instead of conventional endodontics. Surgery is indicated when conventional techniques cannot be used.
Gary B. Carr, DDS, a San Diego endodontist, invented the Ultrasonic Retrotip. Retrotip fits into limited access areas to produce practically perfect preparations.
Orthodontic brackets that use edgewise, and Johnson twin-wire, or Universal bracket techniques were bonded to three or four adjacent teeth, at a specific height from the tips of their cusps. A straight piece of wire was then laid passively in the horizontal channel of the brackets. This orthodontic device has certain disadvantages both for patient and dentist, such as an increased risk of dental caries, trauma to adjacent soft tissue, compromised esthetics, and technically difficult construction of a therapeutic device.
This clinical report describes an alternative for forced eruption that minimizes the need for special orthodontic devices.
Effect of 2% chlorhexidine on microtensile bond strength of composite to dentin
J Adhes Dent. 2003 Summer;5(2):129-38. de Castro FL, de Andrade MF, Duarte Junior SL, Vaz LG, Ahid FJ. Department of Restorative Dentistry, Araraquara School of Dentistry, UNESP Araraquara, Sao Paulo, Brazil. email@example.com PURPOSE: To evaluate the effect of 2% chlorhexidine on the microtensile bond strength of composite resin to dentin treated with three dentin bonding systems. MATERIALS AND METHODS: Flat dentinal surfaces were prepared in 24 extracted human third molars. Teeth were randomly divided into 8 distinct experimental groups according to the adhesive applied (Prime & Bond NT, Single Bond and Clearfil SE Bond), the application (yes/no) of chlorhexidine, and the time point at which it was applied (before or after acid etching the dentin). Composite resin blocks were built up over treated surfaces, and teeth were then stored in water at 37 degrees C for 24 h. Samples were thermocycled, stored under the same conditions, and then vertically sectioned, thus obtaining specimens with 1.0 +/- 0.1 mm2 cross-sectional area. Specimens were stressed in tension at 0.5 mm/min crosshead speed. Bond strength results were evaluated using a one-way ANOVA (p < 0.05). The modes of failures were verified using optical microscopy. Dentin disks were obtained from 3 additional teeth treated in the same manner for observation under SEM. The most representative samples of fractured specimens were also observed under SEM. RESULTS: No statistically significant differences of bond strength values were found between any groups. Failures occurred mainly within the bond; exclusively adhesive fractures (adhesive-dentin) were not observed. CONCLUSION: The 2% chlorhexidine solution, applied before or after acid etching of the dentin, did not interfere with the microtensile bond strength of composite resin to the dentin treated with Prime & Bond NT, Single Bond, or Clearfil SE Bond bonding systems.