SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
A case of false diagnosis of cracked tooth syndrome is reported, illustrating an instance in which all of the diagnostic criteria suggested reasons for the syndrome; however, the actual cause was related to atypical root canal anatomy and external root resorption of the tooth in question.
In examination of ground sections of human third maxillary molar teeth, the granular layer of Tomes was shown to consist of expansion of dentinal tubules. The microradiographic density was decreased well inside the layer. It was postulated that the findings were expressions of dentin resorption. The theory was tested experimentally in rats fed a cariogenic diet with low calcium and phosphorus. The morphology of mandibular molar teeth was studied by electron probe microanalysis and by microradiography. It was concluded that the primary event in cariogenesis was an expansion of peripheral dentinal tubules with formation of confluent microcavities and, thus, an unmasking of the granular layer of Tomes, which normally is only potential. A subsequent loss of mineral density in the outer enamel eventually caused breakdown of the outer enamel with caries visible from the surface. The loss of density within the enamel was postulated to result from interruption of the normal flux of nutrients, metabolites and ions between the dentin and enamel. Whereas an increase in dietary calcium and phosphorus delayed and reduced significantly, but did not prevent cariogenesis, it supported the theory that experimental caries in rats is a metabolic disease with the peripheral dentin the primary target.
AIM: To evaluate the extraradicular pH and hydrogen peroxide (HP) diffusion when either 35% carbamide peroxide (CP), 35% HP or sodium perborate (SP) is used for intracoronal bleaching of artificially discoloured teeth. METHODOLOGY: Single rooted extracted human premolars were stained with whole blood cells. After shaping and cleaning, they were root filled and a base cement placed 1 mm below the buccal cementoenamel junction (CEJ). Four cemental defects were prepared just below the CEJ on each root surface. The teeth were randomly divided into four groups of 11 specimens, and intracoronally bleached using CP, HP, SP or distilled water (CL). Each tooth was suspended in a vial of distilled water and bleached for 7 days. The pH of the extraradicular distilled water was tested at 0, 1, 2 and 7 days and the HP that diffused through the root quantified using the Ferrous Oxidation-Xylenol Orange 2 Assay. The results were analysed using the one-way anova and Scheffe tests. RESULTS: Carbamide peroxide produced the greatest increase and HP the least pH change (P < 0.05 except day 1), SP was intermediate. From day 1 onwards, radicular diffusion of HP was greatest with HP and least with CP (P < 0.01), again SP was intermediate. There was no significant difference between CP and SP. CONCLUSIONS: Carbamide peroxide had very low levels of extraradicular diffusion of HP, in the presence of cemental defects. It could be an alternative to the other intracoronal bleaching agents.
The interrelationship between periodontal and endodontic disease has aroused much speculation, confusion, and controversy. Pulpal and periodontal problems are responsible for more than 50% of tooth mortality today. Diagnosis is often difficult since these diseases have been studied primarily as separate entities. The toxic substances of the pulp may initiate periodontal defects through canal ramifications and patent dentinal tubules, thus impairing wound healing in regenerative procedures. Although no studies exist addressing the direct effect of pulpal infection on the outcome of guided tissue regeneration (GTR) procedures, several studies do indicate that pulpal status may play a significant role toward the end results of GTR. This review article discusses the potential influence of endodontic treatment on the long-term outcomes of GTR. Potential pathways between the pulp and periodontal ligament, which may be responsible for the failure of the regeneration of new periodontal attachment apparatus, are explored. Examination and review of the clinical and research findings in the literature relating to perio-endo lesions are made to demonstrate that a negative influence may exist between GTR outcomes and the status of the pulp.
Forty extracted maxillary central incisors were instrumented at the working length to a #50 file. The roots were sectioned transversely with a diamond disk at 7 mm from the anatomical apex. At the opening of the root canal of each section, hemicircular cavities were drilled with a specially designed bur. The corresponding root sections were cemented with glue, thus obtaining root canals with similar cavities that simulated internal resorptions. Teeth were embedded in plaster casts to facilitate their handling. The specimens were randomly separated into four groups of 10. The following obturation techniques were evaluated: lateral compaction (group A), hybrid technique (group B), Obtura II (group C), and Thermafil (group D). AH26 was used as the sealer. After obturation, the plaster was removed and the teeth were radiographed in buccolingual and mesiodistal directions to evaluate the quality of the obturation at the IRC. The incisors were then cut with a scalpel at the same level as the previous section, to examine, under a stereomicroscope, the type of material that filled the IRC. Obtura II gave the best results and in most of the specimens obturated with this technique, the IRC were filled mainly with gutta-percha. Statistical analysis of the data indicated that the differences between group C and the other groups were significant (P < 0.05).
Secondary retention refers to the cessation of eruption of a tooth after emergence. This may be the result of pathological changes in the periodontal ligament. The aim of this study was to describe the morphological and histological aspects of the radicular surface of secondarily retained permanent molars. The roots of 12 secondarily retained molars and two control molars, were examined by means of scanning electron microscopy (SEM) and light microscopy (LM) in order to analyse the occurrence and localisation of ankylosis. With SEM it was observed that the root surface of retained molars showed local areas covered with bonelike tissue. LM of these areas showed that this tissue was bone in direct contact with the root surface (ankylosis). In 11 cases, the areas of ankylosis were observed in the bifurcation area and at the interradicular root surface. In the remaining case, ankylosis was located at the outer root surface. The results of this study endorse the assumption that focal ankylosis is an important factor in secondary retention. Treatment recommendations must be based on this fundamental principle, because orthodontic movement of ankylotic molars is not possible.
OBJECTIVE: The aim of this study was to determine the response of the residual epithelial network following traumatic breakdown of the periodontal ligament (PDL). METHODS: Mandibular incisor sections with PDL (experimental) and sections denuded of PDL (control) from 4- to 6-week-old Wistar-Furth rats were transplanted into the defects created in the frontal bone of the recipient syngeneic rats. At intervals, the defects with implanted teeth roots were collected and processed for histological and biochemical examination. Immunolocalization of epithelial cells was performed to monitor their phenotypic changes during transplantation healing period. RESULTS: (1) Histological observation of the experimental sample revealed the sequence of cellular response characterized by an initial degeneration of PDL followed by a proliferation of granulation tissue. There was also a marked odontoblastic reaction with extensive deposition of regular dentine within the pulp chambers. In the control group, initial signs of bony fusion with dentine led to an extensive ankylosis and bone replacement between roots and defects. (2) Immunostaining indicated that, in experimental groups, the pattern of regularly spaced epithelial cells lying in close approximation to the root surface was distinct 10 days post-transplantation but became diminished afterwards. The immunoreaction against epithelial cells was negative in the control. CONCLUSION: Residual PDL is essential to prevent ankylosis after trauma and epithelial cells may facilitate the re-establishment of root-PDL-bone complex by transforming into mesenchymal cells.
OBJECTIVE: To assess associations between epidemiologic and laboratory variables and calciotropic hormones in cats with odontoclastic resorptive lesions (ORLs). ANIMALS: 182 client-owned cats older than 1 year of age with oral disease. PROCEDURE: Information on medical history, behavior, living environment, and feeding management was assessed by use of a questionnaire. After induction of general anesthesia, oral examination was performed following standardized protocols and included dental probing and full-mouth radiography. Laboratory analyses included evaluation of FeLV-FIV status, serum biochemical analyses, CBC, urinalysis, and serum concentrations of intact parathyroid hormone (iPTH), parathyroid hormone-related peptide (PTHrP), 25-hydroxyvitamin D (25-OHD), free thyroxine (fT4), and ionized calcium (iCa). RESULTS: ORLs were identified in 72.5% of cats. Mandibular third premolars were the most commonly affected teeth. Cats with ORLs were significantly older (mean, 9.2 years) than cats without ORLs (mean, 6.6 years). Multivariate logistic regression analysis revealed that 25-OHD, urine specific gravity, jaw-opening reflex on probing, and missing teeth were significant variables, even after accounting for age. Cats with ORLs had significantly higher mean serum concentration of 25-OHD (112.4 nmol/L) and significantly lower mean urine specific gravity (1.0263), compared with cats without ORLs (89.8 nmol/L and 1.0366, respectively). CONCLUSIONS AND CLINICAL RELEVANCE: Results did not indicate associations between iPTH, PTHrP, or fT4 and development of ORLs. In affected cats, the importance of high serum 25-OHD and low urine specific gravity has not been determined.
INTRODUCTION: Lower third molars show the highest incidence of impaction and have been held responsible for pathologies such as pericoronitis, periodontitis, second molars tooth-crown resorption, pain, cysts or odontogenic tumors, primary or secondary crowding of the dentition. Early removal of these teeth to prevent the overmentioned problems is widely acknowledged, as many studies demonstrated a direct correlation between age and incidence of complications. These studies mostly refer to adult patients, while studies about germectomies are few. Because recent contributions showed that the risk of development of these pathologies in presence of impacted third molars is quite low while a certain morbidity associated to this procedure may be expected, a very careful risk to benefit ratio must be considered. The purpose of this study was therefore to compare the incidence of complications and side effects in three age groups, in order to obtain some informations about the choice of the best moment for operation. MATERIALS AND METHODS: The patients, 462 females and 406 males, were divided, according to age, in the following three groups: group A included patients from 9 to 16 years; group B included patients from 17 to 24 years; group C included patients over 24 years. All patients were treated under local anesthesia; surgical procedure and instruments were standardized. RESULTS: In group A, formed by 500 germectomies, the incidence of complications was 2.6% (10 instances of secondary infections, 2 instances of trismus, 1 instance of excessive postoperative bleeding). Group B included 570 procedures and the incidence of complications was 2.8% (3 instances of alveolar osteitis, 7 instances of secondary infections, 2 instances of excessive postoperative bleeding, 2 instances od second molar lesions, 1 instance of inferior alveolar nerve paresthesia, 1 instance of trismus). Group C included 430 procedures and the incidence of complications was 7.4% (2 instances of second molar lesions, 9 instances of alveolar osteitis, 8 instances of secondary infections, 4 instances of excessive postoperative bleeding, 6 instances of inferior alveolar nerve paresthesia, 3 instances of trismus). All complications were transient; in one instance only of mandibular nerve paresthesia in group C symptoms were still present 25 months after the operation. DISCUSSION AND CONCLUSIONS: This study has shown no significant differences between group A and B, while complications significantly increase in group C. Recent researches have shown that: a) there is a low risk of development of pathologies correlated to third molar impaction; b) nowadays there are not valid criteria to evaluate the future eruption of the impacted tooth; c) a direct correlation between third molar impaction and anterior dental crowding hasn't been demonstrated yet; d) morbidity of the procedure is relevant. Therefore germectomy should be performed: a) if morphostructural alterations or ectopic impactions are present; b) in case eruption is not allowed for dysplastic alterations of the germs or pathological processes of the mandible; c) to gain space in the posterior segments of the lower jaw when distalization of first and second molars is necessary; d) in case of excessive anterior-posterior mandibular growth.
OBJECTIVE: To determine elemental composition of teeth with and without odontoclastic resorption lesions (ORL) in cats. SAMPLE POPULATION: Normal teeth from 22 cadaver cats and ORLaffected teeth from 21 cats admitted to the veterinary hospital for dental treatment. PROCEDURE: An electron microprobe was used to analyze weight percentages of calcium, phosphorus, fluorine, sodium, magnesium, sulfur, potassium, and iron in enamel, dentin, and cementum. RESULTS: Calcium and phosphorus were the most abundant elements. Fluorine, sodium, and magnesium combined were < 5% and sulfur, potassium, and iron combined were < 0.1% of total elemental composition. In enamel of normal teeth, a significant sex-by-jaw location interaction was seen in mean (+/- SD) phosphorus content, which was higher in mandibular teeth of females (1764+/-0.41%) but lower in mandibular teeth of males (16.71+/-0.83%). Mean iron content in dentin of normal teeth was significantly lower in mandibular teeth than maxillary teeth (0.014+/-0.005% vs 0.023+/-0.019%). Mean enamel sodium content was significantly higher (0.77+/-0.046% vs 0.74+/-0.025) and mean enamel iron content was significantly lower (0.017+/-0.008% vs 0.021+/-0.005%) in ORLaffected teeth, compared with normal teeth. In cementum, mean fluorine content was significantly lower (2.98%+/-0.27 vs 2.99+/-0.20%) and mean magnesium content was significantly lower (0.54+/-0.13% vs 0.60+/-0.13%) in ORL affected teeth, compared with normal teeth. CONCLUSIONS AND CLINICAL RELEVANCE: Results of our study establish baseline mineral content of enamel, dentin, and cementum for normal teeth in cats. Minimal differences in mineral content of enamel and cementum of normal and ORL-affected teeth were detected.
Secondary retention refers to the cessation of eruption of a tooth after emergence neither due to a physical barrier in the path of eruption nor as a result of an abnormal position. In this study, the clinical and radiographic features of 81 secondary retained permanent molars in a group of 53 patients were evaluated. Retained molars removed for therapeutic reasons (n = 38) were examined histologically to detect any areas of ankylosis. The first molars in the mandible and maxilla were most frequently affected. The mean infraocclusion at the patients' first visit was 4.3 +/- 1.9 mm. After 6 months, infraocclusion increased in adolescents but was stable in adults. Tilting of the adjacent teeth was observed in 39 cases. A sharp, solid percussion sound and a partial absence of the periodontal ligament space on radiographs were noted in less than one-fifth of the affected molars, while histological evaluation revealed that local areas of ankylosis were present in all cases. From the data relating to the 38 molars removed for therapeutic reasons, the sensitivity of the percussion test and radiographic evaluation was found to be 29 and 21 per cent respectively. During a period of 4 years, six new cases of secondary retention were observed in the same population. From this study it is concluded that secondary retention of permanent molars seems to be associated with focal ankylosis and that percussion tests and radiographs are not sufficiently reliable to exclude the presence of ankylotic areas. The presence of ankylotic areas and tendency of infraocclusion to increase in adolescents but to be stable in adults have major implications for therapy.
On non-vital deciduous molars, inter-radicular bone resorption is often an indication of extraction. The endodontic treatment of these teeth by means of zinc oxide-eugenol (ZOE) paste also showed its limits. To mitigate the deficiencies of this material, we suggested a preliminary treatment by means of calcium hydroxide (Ca(OH)2) for its anti-inflammatory and antiseptic properties as well as its ability to stimulate calcified tissues apposition or remineralisation. This study concerns 21 non-vital deciduous molars. X-rays excluded any lesion of the underlying permanent bony crypt (bone tissue) as well as any inflammation of the dental follicle. After preparation, root canals were filled by means of Pulpdent. An initial X-ray check was made 15 days and then every 3 months. After disappearance of the inflammatory resorption, root canal fillings were performed with ZOE paste. The remineralisation of the inter-radicular alveolar bone was observed for 14 deciduous molars, which were then filled using ZOE. The remineralisation period varies from 3 to 18 months depending on the scale of the lesion. Of the 7 failed treatments, 3 failed following downfall of the crown filling material, and 2 due to failure to keep appointments and late replacement of resorbed Ca(OH)2. On 2 teeth, the treatment did not stop the lesion forming. Calcium hydroxide (Ca(OH)2) give encouraging results in the treatment of inter-radicular alveolar bone resorption of non-vital deciduous tooth. Its fast resorption requires rigorous controls, frequent refills, and thus strong motivation on the part of the child and parents. It cannot, on any account, be considered as permanent filling material.
Explore the source record for details and available documents.
BACKGROUND: The prophylactic removal of asymptomatic impacted wisdom teeth is defined as the (surgical) removal of wisdom teeth in the absence of local disease. Impacted wisdom teeth have been associated with pathological changes, such as inflammation of the gums around the tooth, root resorption, gums- and alveolar bone disease, damage of the adjacent teeth, the development of cysts and tumours. Several other reasons to justify prophylactic removal have also been given. Wisdom teeth do not always fulfil a functional role in the mouth. When surgical removal is carried out in older patients the risk of more postoperative complications, pain and discomfort increases. Nevertheless, in most developed countries the prophylactic removal of trouble-free wisdom teeth, either impacted or fully erupted, has long been considered as 'appropriate care'. Prudent decision-making, with adherence to specified indicators for removal, may reduce the number of surgical procedures by 60% or more. It has been suggested that watchful monitoring of asymptomatic wisdom teeth may be an appropriate strategy. OBJECTIVES: To evaluate the effect of prophylactic removal of asymptomatic impacted wisdom teeth in adolescents and adults compared with the retention of these wisdom teeth. SEARCH STRATEGY: The following electronic databases were searched:The Cochrane Oral Health Group Trials Register (4 August 2004), the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (1966 to 4 August 2004), PubMed (1966 to 4 August 2004), EMBASE (1974 to 4 August 2004). There was no restriction on language. Key journals were handsearched. An attempt was made to identify ongoing and unpublished trials. SELECTION CRITERIA: All randomised or controlled clinical trials (RCTs/CCTs) comparing the effect of prophylactic removal of asymptomatic impacted wisdom teeth with no-treatment (retention). DATA COLLECTION AND ANALYSIS: Assessment of relevance, validity and data extraction were conducted in duplicate and independently by three reviewers. Where uncertainty existed, authors were contacted for additional information about randomisation and withdrawals. A quality assessment of the trials was carried out. MAIN RESULTS: Only three trials were identified that satisfied the review selection criteria. Two were completed RCTs and both assessed the influence of prophylactic removal on late incisor crowding in adolescents. One ongoing RCT was identified, but the researchers were unable to provide any data. They intend to publish in the near future and information received will be included in updates. Although both completed trials met the inclusion criteria of the review, regarding participants characteristics, interventions and outcomes assessed, different outcomes measures were assessed which prevented pooling of data. AUTHORS' CONCLUSIONS: No evidence was found to support or refute routine prophylactic removal of asymptomatic impacted wisdom teeth in adults. There is some reliable evidence that suggests that the prophylactic removal of asymptomatic impacted wisdom teeth in adolescents neither reduces nor prevents late incisor crowding.
Explore the source record for details and available documents.
Extracted human deciduous teeth undergoing physiological root resorption were fixed with a mixture of formaldehyde and glutaraldehyde and processed for scanning (SEM) and analytical transmission electron microscopy, as well as acid trimetaphosphatase cytochemistry. The granulated tissues, which are rich in multinucleated odontoclasts and capillary vessels, formed various resorption lacunae on the resorbing dentin surfaces. SEM observations of dentin surfaces treated with sodium hypochlorite revealed two types of resorption lacunae: deep, round lacunae in which the peritubular matrix of dentinal tubules was strongly dissolved; and shallow, irregular lacunae with intact peritubular matrix. In trypsin-treated materials, the resorption surfaces were characterized by the presence of numerous collagen fibers in both the peritubular and intertubular matrices, suggesting demineralization of the surface dentin. Odontoclasts were characterized by the presence of abundant mitochondria, perinuclear stacks of Golgi membranes, various lysosomes, numerous endocytotic vacuoles, and a well-developed ruffled border against the resorption lacunae. Most endocytotic vacuoles were distributed in the cytoplasm between the ruffled border and the nuclei. In undemineralized ultrathin sections, the surface dentin of resorption lacunae consisted of collagen fibers and apatite crystals and had a lower packing density than those in unresorbed, deeper dentin. Many apatite crystals were demonstrated to be present in the extracellular channels of the ruffled border and in adjacent endocytotic vacuoles derived from it. Lysosomes located in the perinuclear cytoplasm of odontoclasts contained amorphous dense material and/or a small amount of crystals. An energy-dispersive x-ray microanalysis of apatite crystals in undemineralized sections indicated that the energy spectrum peaks of Ca and P detected from crystals in resorbing dentin were much lower than those in unresorbed dentin. Similarly, lower spectrum peaks of Ca and P were obtained from crystals found in the ruffled border and endocytotic vacuoles of odontoclasts. A slight trace Ca peak also was detected in the amorphous dense material in lysosomes of odontoclasts. The enzyme cytochemistry of lysosomal acid trimetaphosphatase indicated that odontoclasts had intense enzymatic activity in the Golgi membranes, endoplasmic reticulum cisternae, lysosomes, and endocytotic vacuoles. Dense reaction precipitates of enzymatic activity also were found along the dentin surfaces of resorption lacunae occupied by odontoclast ruffled borders.(ABSTRACT TRUNCATED AT 400 WORDS)
This study examined the relative ease with which three dissimilar mineralized tissues from one individual organ were resorbed by osteoclasts in vitro. Cells released from the long bones of prehatch chicks by agitating fragments of the chopped bones in medium were cultured for 24 hours on slices cut from an Elephas maximus molar so that enamel, dentine, and coronal cementum were present in bands on the surface of the slice. The resultant pits were measured using a video-rate, line-confocal reflection light microscope system. Variations in tissue mineralization were characterized by analysis of digital backscattered electron images. The enamel pits were smaller than the dentine and the cementum pits, but the dentine and cementum pits were not significantly different from each other. The sizes of the pits correlated with the relative mineral densities of the three tissues, showing that the rate of osteoclastic destruction of calcified tissues is inversely proportional to mineral density. This indicates that the initial step in osteoclasis, the removal of the mineral phase, determines the volume removed and is the rate-limiting step.
Increased systemic bone loss may be a risk factor for tooth loss by contributing to the resorption of tooth-supporting alveolar bone. Concurrent longitudinal associations between tooth loss and bone loss at the whole body, femoral neck, and spine were examined in 189 healthy, white, dentate, postmenopausal women who participated in three intervention trials conducted within a 7-year period. None of the subjects was taking estrogen. Bone mineral density (BMD) was measured by dual photon or dual energy X-ray absorptiometry. Teeth were counted at baseline; number and timing of teeth lost over the observation period were assessed by questionnaire. All analyses were controlled for years since menopause, body mass index, number of teeth at baseline, smoking status, and the assigned treatment during each study. These interventions were calcium (Ca) or placebo (P) in Study I, vitamin D+Ca or P+Ca in Study II, and 1 of 2 doses of vitamin D+Ca in Study III. Age at baseline (mean +/- SD) was 59 +/- 6 years and the number of teeth remaining was 23 +/- 7. Women who lost teeth during the 7-year follow-up (n = 45) experienced less favorable changes in BMD at all sites compared with 144 women who lost no teeth (whole body mean +/- SE, -0.35 +/- 0.08%/year versus -0.11 +/- 0.05, P < 0.01; femoral neck -0.48 +/- 0.38%/year versus -0.14 +/- 0.35, P < 0.05; and spine, +0.05 +/- 0.21%/year versus +0. 45 +/- 0.16, P < 0.05). For each 1%/year decrement in BMD, relative risks (and 95% CI) of losing a tooth were significantly elevated at the whole body (RR = relative risks, CI = confidence interval) (RR = 4.83, CI = 1.72-13.52, n = 180), femoral neck (1.50, 1.02 to 2.22, n = 189), and spine (1.45, 1.00 to 2.11, n = 167). These results provide support for a role of systemic bone loss in the development of tooth loss among postmenopausal women.