Endodontic therapy in a fused mandibular molar.
This case report describes the endodontic management of fusion involving a mandibular third molar and a fourth molar (distomolar).
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This case report describes the endodontic management of fusion involving a mandibular third molar and a fourth molar (distomolar).
The goal of this in vitro study was to evaluate the relative cytocompatibility of three endodontic materials: calcium hydroxide, a calcium oxide-based compound, and a zinc oxide-eugenol-based sealer. The evaluation was conducted 24, 72, and 168 h after contact with the compounds and involved three complementary techniques: a colorimetric cytotoxicity test, scanning electron microscopy, and flow cytometry. The results we obtained confirmed the initial cytotoxicity of the zinc oxide-eugenol-based sealer and showed that the calcium oxide-based compound had the same relative cytocompatibility as calcium hydroxide.
The absence of adequate testing standards for engine-driven nickel-titanium (NiTi) instruments necessitates further study of these instruments in all areas. This study examined three groups of engine-driven rotary NiTi endodontic instruments (Profile, Hero, and Quantec) and assessed the times for dynamic fracture in relation to the radius of curvature to which the instruments were subjected during preparation, with the instrument diameter determined by size and taper and the mode by which the fracture occurred. Ten instruments were randomly selected representing each size and taper for each group and for each radius of curvature: 600 in total. The instruments were rotated at 350 rpm and introduced into a tempered steel curve that simulated a canal. Two radii of curvature of canals were used: 5 and 10 mm. Time at fracture was noted for all files, and the fracture faces of each file were analyzed with scanning electron microscopy. Radius of curvature was found to be the most significant factor in determining the fatigue resistance of the files. As radius of curvature decreased, fracture time decreased. Taper of files was found to be significant in determining fracture time. As diameter increased, fracture time decreased. In all cases, fracture was found to be of a ductile nature, thus implicating cyclic fatigue as a major cause of failure and necessitating further analyses and setting of standards in this area.
For this survey, 92 vertically fractured endodontically treated teeth were evaluated clinically and radiographically before and after extraction. The maxillary second premolars (27.2%) and mesial roots of the mandibular molars (24%) were the most fractured teeth. In 67.4% of the teeth, a solitary buccal pocket was present; in 34.8%, a fistula frequently appeared closer to the gingival margin than to the apical area. A lateral radiolucency or a combination of lateral and periapical radiolucency was found in more than half of the cases. The general practitioners correctly diagnosed vertical root fracture in only one-third of the 92 fractured teeth in this survey.
Endodontic therapy was performed on 14 teeth in juveniles with inflamed or necrotic pulps. The patients were recalled at 6-month intervals for radiological and clinical examinations. After 1 yr, periapical surgery was performed on six teeth. After 18 months, 5 more patients were subjected to periapical surgery and, after 2 1/2 years, 3 more patients had periapical surgery. A small block section containing the root tip and surrounding tissues was removed from all of the patients. Radiographs showed reductions in size, but not elimination, of periapical lesions. Histological examinations revealed that most root canals were overfilled. Inflammation persisted around zinc oxide-eugenol particles beyond the tooth apexes. In addition, gutta-percha overfilling enhanced the proliferation of cell rests of Malassez. In some cases, dentin filings were found at and beyond the tooth apexes. The formation of new hard tissue was stimulated by the presence of dentin chips.
This case report documents the treatment of an endodontic patient who experienced a type 1 hypersensitivity reaction to latex. The dental, medical, and environmental aspects of treating latex allergic patients are reviewed. Because gutta-percha and latex rubber are similar compounds, the possible cross-reactivity of these materials is discussed.
OBJECTIVES: Adhesive cements used with metal endodontic posts may decrease fracture in non-vital teeth. Results from studies that evaluate cements for post retention by pulling posts out of extracted teeth are difficult to interpret owing to the number of interfaces where fracture might occur. The objective of this study was to isolate the metal/cement interface for tensile bond strength testing and microscopic observation. METHODS: Three metals and seven cement treatments were examined for bond strength by using a truncated cone tensile test. The bond strength data were analyzed by a two-way ANOVA and Scheffé's multiple comparison test at p = 0.05. Specimens were examined at 50x magnification to determine the failure mode and with scanning electron microscopy (500x) to observe the surfaces after debonding. RESULTS: Significant differences in tensile bond strengths were found among cements compared within two of the metal groups. One of the metal groups had no significant differences among cement bonds. When comparing within cement treatment groups, two groups had significant differences in bond strength among the metals. Microscopic observations revealed adhesive, cohesive and mixed failure modes that varied with cement treatment and metal combination. The interaction between metal and cement was a critical determinant of the strength and characteristic fracture mode of the bond achieved. SIGNIFICANCE: Some of the cement treatments performed better (i.e., higher bond strength) with some metals than with others. Other cements had similar bond strengths with all three metals. Because of this interaction, careful consideration of the materials combination should help to maximize the bond at the metal/cement interface.
It is known that pets with broken teeth or teeth with other diseases of the pulp suffer considerable pain and frequent infection. To ignore these problem teeth would not only be inhumane, it would risk chronic infection, abscessation, and tooth loss. Although extraction of these teeth is sometimes necessary, the procedure is often difficult to perform and painful for the animal. The resultant tooth loss is cosmetically displeasing and, frequently, there is compromise in function. The endodontic treatment of these teeth, on the other hand, is relatively easy to perform. It almost always results in immediate cessation of pain and will usually allow the tooth to remain functional for the lifetime of the pet.
Subcutaneous emphysema is well known, but diffusion of gas into the mediastinum is not so common, particularly if it is caused by treatment of a root canal without apparent osseous fenestration or mucoperiostal lesions. We report a case of iatrogenic pneumomediastinum and facial emphysema after endodontic treatment. The diagnosis was confirmed by computed tomography, and the patient recovered after treatment with intravenous antibiotics and analgesia.
OBJECTIVES: The purpose of this study was to investigate the stress patterns associated with prefabricated endodontic posts during the various stages of insertion according to a number of design characteristics. METHODS: In a photoelastic material with elastic properties comparable to dentin, analyses were performed of the overall stress patterns with polarized light revealing substantial differences in stresses generated by the various posts. The effects of variations in design for certain configurations of the posts were also assessed. RESULTS: One geometric feature was the retentive thread of the post. The stress patterns within the photoelastic material revealed a homogeneous distribution of stress along the entire length of the thread, and more threads induced additional stress. The stress recorded with a vent when the pitch of the thread was 0.8-1.0 mm was classified as minimal-to-mild stress. Another geometric feature considered was the head (coronal extension) of the post. Minimal stress was recorded in the material in contact with the head and the apical end of the post when the contact surface of head was more than 3 mm2. CONCLUSIONS: This study suggests that during insertion of threaded posts the least stress occurs when the head contact surface is sufficient (> or = 3 mm2). A thread with a pitch of 0.8-1.0 mm is most desirable in stress reduction. The number of windings should also be limited (less than six windings) as samples with a substantial number of windings (N = 13 or 30) produce severe stress.
OBJECTIVES: This study was undertaken to evaluate the effect of several endodontic irrigation solutions on the microhardness of root canal dentine. METHODS: Eighteen freshly extracted maxillary incisors were used in this experiment. The crowns of teeth were sectioned at the cemento-enamel junction. The root canals were instrumented to an apical size #50 file, and irrigated with saline solution. The prepared roots were divided equally into two groups each of nine roots. Each root was sectioned transversely into cervical, middle and apical segments. The three sections of each root were separately mounted in a metal chuck with acrylic resin. The coronal dentine surfaces of the root segments were polished. The microhardness of the dentine was measured for the purposes of control data at 500 microns and 1 mm from the pulpo-dentinal interface. The canal portions in the root segments included in the first group were irrigated with 3% H2O2 and 5% NaOCl solutions used alternatively, while 17% EDTA solution was the irrigation used in the second group. One millilitre of each solution/segment was applied for 60 s exposure time. After irrigation, dentine microhardness was re-assessed and compared with the control values obtained before the irrigation treatment. Data were statistically analysed using ANOVA and Scheffe's test. RESULTS: The results showed that, irrigation with either H2O2/NaOCl or EDTA decreased the microhardness value of root dentine. Irrigation with EDTA gave more reduction of dentine hardness compared to H2O2/NaOCl irrigation. The reduction of KHN of dentine following the irrigation treatment was statistically significant (p < 0.05) at both levels of hardness measurement. CONCLUSIONS: Both H2O2/NaOCl and EDTA irrigating solutions significantly reduced the microhardness of root canal dentine.
A patient with asymptomatic maxillary sinus aspergillosis (MSA) is presented. Aspergillosis developed around a foreign body. Inductively coupled plasma mass spectrometry (ICP) revealed that the foreign body corresponded to gutta-percha used for endodontic fillings.
An observer strategy involving trained and experienced examiners was used in a large series of endodontic surgery cases, evaluated radiographically 1 year after the operation. The cases were grouped in 1 of the following 4 healing groups; complete healing, incomplete healing (scar tissue), uncertain healing and unsatisfactory healing (failures). The radiographs were first examined separately by an oral surgeon and an endodontist. Deviating cases were subjected to joint evaluation. The overall agreement before joint interpretation was satisfactory: 63% when corrected for chance agreement. Agreement after joint evaluation reached 94% of the total material. Disagreement and difficult borderline cases were judged by an oral radiologist. He was more pessimistic than the 2 main examiners. The identification of healed cases with apical bone which had not yet obtained normal radiopacity and structure was difficult. Altogether, the observer consistency was satisfactory; the selection of experts increased the chances of "true" diagnoses; the important screening function of the one-year control was confirmed. The applied strategy and the classification are recommended for follow-up studies.
Occasionally, an orthodontic patient will accidentally traumatize a maxillary anterior tooth before or during orthodontic treatment. In some situations, the trauma will be substantial and avulse the tooth. In other accidents, the tooth may not avulse, but the pulp becomes nonvital. If the pulp is devitalized, and the root has not fully formed, the apex of the root canal may be wide. In this situation, the endodontist may recommend apexification procedures to help close the apex before conventional obturation of the root canal. If the patient is currently undergoing orthodontic movement of the traumatized incisor, what effect will the tooth movement have on the success of the apexification? If the tooth were avulsed, replanted, and then ankylosed, should it be extracted? If so, when should the ankylosed incisor be removed? What effect will further facial growth have on the ankylosed tooth and the potential to achieve a successful esthetic restoration? The answers to these questions are important during the interdisciplinary treatment planning of the patient with traumatized teeth. This article will elucidate the endodontic-orthodontic considerations for patients with traumatized anterior teeth.
OBJECTIVE: In this study, we aimed to investigate the occurrence of several microbial species in cases of failed endodontic therapy by means of the polymerase chain reaction (PCR). Study design Root canal samples were taken from 22 root-filled teeth with persistent periradicular lesions selected for re-treatment. DNA was extracted from the samples and analyzed for the presence of 19 microbial taxa by using the polymerase chain reaction. RESULTS: All samples were positive for at least 1 of the target microbial species. Enterococcus faecalis was the most prevalent species-detected in 77% of the cases. The other most prevalent species were Pseudoramibacter alactolyticus (52%), Propionibacterium propionicum (52%), Dialister pneumosintes (48%), and Filifactor alocis (48%). Candida albicans was found in 9% of the samples. The mean number of species in samples filled up to 2 mm short of the radiographic apex was 3 (range, 1-5), whereas cases in which the filling was greater than 2 mm from the apex yielded a mean of 5 species (range, 2-11). This difference was statistically significant (P <.05). CONCLUSIONS: Microorganisms occurred in all cases of root-filled teeth associated with periradicular lesions, which lends strong support to the assertion that treatment failures are rather of infectious etiology, caused by persistent or secondary intraradicular infections. E faecalis was the most prevalent species, followed by 4 other anaerobic species: P. alactolyticus, P. propionicum, D. pneumosintes, and F. alocis. All examined samples harbored at least 1 of the following gram-positive bacterial species: E. faecalis, P. alactolyticus, or P. propionicum.
Few data have been collected regarding the prevalence and quality of root canal therapy in American populations. European studies of various populations were used as a model for the evaluation of the prevalence and technical standard of endodontic treatment in a patient group seen for screening at a United States dental school. Full-mouth radiographic series were examined for the presence of root fillings, periapical pathologic conditions, and coronal restorative status. The obturation density and length were also recorded. Of 5272 teeth examined, 5.5% had root fillings. Periapical disease was evident in 4.1% of all teeth and 31.3% of root-filled teeth. Lesser-quality root fillings were more strongly associated with periapical disease than were higher-quality obturations. In addition, only 42% of the obturations could be considered technically satisfactory. Such data suggests that more research must be directed toward the study of factors that affect treatment outcome.
The effects of endodontic cements on the cell cycle of MG63 osteoblasts cultured in vitro have been examined. Three groups of compounds were tested. Group I encompassed zinc oxide- and eugenol-based cements (Tubliseal, Argoseal, N2), group II consisted of cements with a phenol group other than eugenol (AH26, Forfenan, Methode R/R), and group III included CaOH-based cements (Biocalex, Endocalex). The cell cycle of MG63 cells was analyzed by flow cytometry; the DNA content was evaluated by means of the propidium iodide uptake method, whereas the proportion of cells in the S phase was defined by the incorporation of bromodeoxyuridine later revealed by a specific antibody. The results showed that some root canal sealers could hamper the periapex healing processes by inhibiting the cell proliferation through a selective action on different phases of the cell cycle.
Various techniques of rigid internal fixation have evolved to achieve skeletal stability during healing. Although the miniplates and screws currently used have many advantages, their placement and presence may present significant difficulties for clinicians subsequently providing treatment. Problems with both endodontic diagnosis and treatment after miniplate fixation are illustrated with three case reports.