Teeth in the line of fracture: to retain or remove?
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ABSTRACT:
SUBMITTER: Samson J
PROVIDER: S-EPMC3052709 | biostudies-other | 2010 Dec
REPOSITORIES: biostudies-other
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Project description:Purpose/introductionTooth loss has been found to be associated with fractures and osteoporosis. However, the associations between number of teeth with bone mineral density as well as with hip fractures have not been explored in the same study setting.MethodsData from the cross-sectional National Health and Nutrition Examination Survey (2005-2010, 2013-2014, and 2017-2018) with completed femoral neck bone mineral density (BMD) measurements, osteoporosis questionnaires, and dentition examinations were analyzed. A total of 15,198 participants, with a mean age of 53.9 and diverse ethnicity, males (52%), and females (48%), were analyzed. Multivariate logistic regression analyses for self-reported hip fractures, self-reported osteoporosis, and measured low femoral BMD accounting for traditional risk factors were tested for the total number of natural teeth (NoT) present, or by NoT in the anterior or posterior segments.ResultsSubjects with fewer natural teeth present were more likely to report a hip fracture, osteoporosis, or having lower levels of femoral neck BMD. With one additional tooth present in the mouth, there was a decreased association with self-reported hip fracture [OR(95%CI) = 0.98(0.96-0.99); P = 0.005] or with less likelihood of having low femoral neck BMD [OR(95%CI) = 0.99(0.97-1.00); P = 0.007].ConclusionsWith the limitation of the cross-sectional study design, results should be interpreted cautiously, yet our analyses point to an association between a decreased number of natural teeth present and self-reported hip fractures or low femoral neck BMD. The number of teeth present could be potentially utilized for assessing risks of hip fracture and osteoporosis. Future research is needed to validate our findings.
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Project description:BACKGROUND:The purpose of this study was to evaluate the effect of the amount of periodontal support on the fracture resistance of root-amputated maxillary molar teeth restored with either direct class. I. restorations or class II. mesio-occluso-distal (MOD) indirect overlay restorations with cuspal coverage. METHODS:Sixty sound maxillary first molars were collected and randomly divided into four groups. In Groups 1 and 2, MOD cavities were prepared and all cusps were reduced by 2 mm, whereas in Group 3 and 4, only a conservative Class I. cavity was prepared. Subsequently, root canal treatment was performed and the mesio-buccal roots were amputated. Groups 1 and 2 were restored with indirect composite overlay, while Groups 3 and 4 received direct composite fillings. After restoration, teeth were embedded as follows: Groups 1 and 3: normal bone level, Groups 2 and 4: furcation involvement. The specimens were submitted to static fracture resistance testing. Fracture thresholds and fracture patterns were measured and evaluated. RESULTS:Group 1 had the highest fracture resistance (2311,6 N) among the restored groups and showed statistically significant difference compared to Group 2 (p = 0.038) and Group 4 (p = 0.011). There was no statistically significant difference in terms of fracture resistance between the rest of the groups. In terms of the fracture patterns, Group 3 was characterized by the highest percentage (60%) of mostly favorable fractures, while the rest of the groups showed predominantly unfavorable ones. CONCLUSIONS:The amount of periodontal support seems to influence the fracture resistance of root-amputated and restored maxillary molars.
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Project description:Background: Ex vivo fracture models are frequently used in human dentistry to provide insights in the fracture mechanisms of teeth. Equine cheek teeth fractures are an important dental pathology, but there has been no research performed to examine the fracture resistance ex vivo. Objective: To evaluate the fracture resistance of equine cheek teeth and identify anatomical predictors that might influence fracture resistance in healthy teeth. It was further evaluated if the presence of a fissure caused a decrease in fracture resistance. Study design: Ex vivo experimental design. Methods: Individual cheek teeth were subjected to a compression load in a universal testing machine until fracture occurred. Testing was performed in two study groups. A first group of healthy cheek teeth was tested to examine anatomical predictors on fracture resistance. A second group comprised cheek teeth with occlusal fissures and an equal number of age- and size-matched fissure-free teeth as controls. The effect of possible predictors on fracture resistance was investigated by regression analysis. Results: In the first group, fracture resistance was significantly influenced by the location on the tooth where testing was performed in both maxillary (p < 0.001) and mandibular teeth (p < 0.001). Additional significantly associated factors were Triadan number in mandibular (p = 0.009) and the mesiodistal length of the occlusal surface of maxillary teeth (p = 0.01). Experimentally induced crown fractures that extended below the simulated bone level were more frequently associated with pulp horn exposure (p < 0.001). In the second group, significant lower fracture loads were recorded in teeth with fissures (mandibular p = 0.006; maxillary p < 0.001), compared to fissure-free teeth. Main limitations: This ex vivo model does not imitate the in vivo masticatory forces and lacks the shock-absorbing properties of the periodontal ligament. Conclusions: The methodology used in this study provides an ex vivo experimental set-up to test fracture resistance of equine cheek teeth enabling evidence-based research to examine the potentially weakening effects of tooth pathology and its treatments. Crown resistance to fracture differed along the occlusal surface of healthy equine cheek teeth, and the presence of fissures further decreased fracture resistance.
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