A comparison of retreatment decisions among general dental practitioners and endodontists.
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This study compared the difference in decision making regarding retreatment of endodontically treated teeth by general dental practitioners and endodontists. Thirty radiographs of endodontically treated teeth taken from undergraduate records with their respective case descriptions were submitted to fifteen endodontists and fifteen general dental practitioners. Seven treatment alternatives were given as choices; reasons for retreatment, if chosen, were also requested and presented as choices. The results showed statistically different decisions among these two groups regarding retreatment cases. More endodontists opted for retreatment of cases, while higher percentages of general dentists decided to observe, not treat or extract. To prevent misdiagnosis and eventually mistreatment, endodontic decision making should be taught. Currently, there are no specific guidelines for management of failed root canal retreatment. It is suggested that guidelines generated by evidence-based dentistry may produce less variation in clinical decision making. (+info)
Root-crown ratios of permanent teeth in a healthy Finnish population assessed from panoramic radiographs.
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An unfavourable root-crown (R/C) ratio caused by short dental roots may result from a developmental deficiency, root resorption after orthodontic treatment, or dental trauma. In the assessment of root shortening, subjective grading has often been used. For objective tooth measurements, varying materials and methods may make the results impossible to compare. This study used a simple, objective method to assess the R/C ratio (relative root length) of mature permanent teeth from panoramic radiographs (PRGs), tested its reproducibility and calculated the mean values of R/C ratios and their variations in a healthy Caucasian (Finnish) population. Two thousand seven hundred and seventy-nine teeth were measured on 108 PRGs. The intra- and inter-examiner reproducibility of the assessment method was good (Pearson correlation coefficients 0.87 and 0.83, respectively; P < 0.001) and the mean R/C ratios did not differ between the repeated measurements (P > 0.05). The biological variance in all cases exceeded the error variance for each tooth. These facts suggest that the method reported in this study can be used in the assessment of the relative root length of 'normal' teeth and its alterations in teeth with developmental or acquired aberrations of dental roots. Males, overall, tended to have higher R/C ratios than females; P-values varied from non-significant to less than 0.01. With the exception of the permanent lateral incisors in males and the permanent second molars in both genders, the ratios of the antagonist teeth were significantly greater in the mandible than in the maxilla (P < 0.05 for the lateral incisors of females; P < 0.001 for all other teeth). Consequently, in quantifying root shortening in developmentally short-rooted teeth, tooth- and gender-specific reference values should be employed. The Finnish R/C data reported here for all teeth except third molars could be used for comparison with other populations, patient groups or individuals where crown-root aberrations are suspected. (+info)
Scanning electron microscopy of root resorption of feline teeth.
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Scanning electron microscopy was carried out on 10 feline extracted permanent teeth from 3 cases with root resorption. Various-sized resorption lacunae were well defined, showing an etched pattern and configuration as shown in human deciduous teeth. In cats, regardless of the shape and depth of lacunae, the resorption lacunae showed opening dentinal tubules in the wall with or without cement matrix apperring only in the deep and round lacunae of human cases. Some specific process of mineralization for repairing dental root resorption was suggested in cats. (+info)
Disturbed root development of permanent teeth after pediatric stem cell transplantation. Dental root development after SCT.
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BACKGROUND: Deficient dental root development has been reported after conventional pediatric anticancer therapy, but less information is available on stem cell transplantation (SCT) recipients. METHODS: Root-crown (R/C) ratios of fully developed permanent teeth were assessed from panoramic radiographs of 52 SCT recipients, who were treated when they were age < 10 years. Using standard deviation scores (SDSs), the authors compared the R/C ratios to the corresponding tooth and gender-specific values in a healthy population. The percentage of affected R/C ratios per individual was examined in a subgroup of 39 (SG39) patients with advanced tooth development. The effects of total body irradiation (TBI) and SCT age on the R/C ratios were studied in TBI and high-dose chemotherapy (HDC = non-TBI) groups and in 3 age groups (< or = 3.0 years, 3.1-5.0 years, > or = 5.1 years). RESULTS: Per individual, 77% of the fully developed permanent teeth were affected in SG39. At the tooth level, in 77% of the 945 teeth studied (52 patients), the R/C ratios were outside +/-2 SDSs. More teeth were affected in the TBI (85%) than in the non-TBI (55%) group (P < 0.001). The teeth of the patients who were ages 3.1-5.0 years old at SCT presented with the most severe aberrations of the R/C ratio (mean SDS = -4.4) whereas the teeth of the youngest (age < or = 3.0 years) and the oldest (age > or = 5.1 years) patients were equally affected (mean SDSs = -3.1 and -3.0, respectively). CONCLUSIONS: Disturbances of dental root growth always followed pediatric SCT. HDC alone intensely harmed root growth but TBI further increased the adverse effects that were most extensive in the patients 3.1-5.0 years at SCT. These sequelae should be taken into account during the lifelong dental follow-up to minimize the clinical consequences of dental injuries. (+info)
Soluble cytokine receptor treatment in experimental orthodontic tooth movement in the rat.
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Pro-inflammatory cytokines, such as interleukin-1 (IL-1) and tumour necrosis factor-alpha (TNF-alpha), are believed to play a role in the biological processes involved in the course of orthodontic tooth movement and especially in root resorption. The inhibition of cytokine activity, e.g. by soluble receptors, could be beneficial in reducing this unwanted side-effect. The aim of this study was to investigate the role of cytokines IL-1 and TNF-alpha in the course of experimentally induced tooth movement. The upper left first molar was moved orthodontically in 80 male Wistar rats using a coil spring with a force of 0.5 N. Starting at day -1, three groups of 20 animals each received daily intraperitoneal injections (ip) of 2 ml of 1 mug/ml soluble receptors (a) to IL-1(sIL-RII), (b) to TNF-alpha (sTNF-alpha-RI) and (c) a combination of (a) and (b). Twenty animals served as the control. After 3, 6, 9 and 12 days, the animals were killed in groups of five. The amount of tooth movement was registered and the maxillae were prepared for histological and histomorphometric analysis. Osteoclasts and odontoclasts were identified using tartrate-resistant acid phosphatase (TRAP) histochemistry. The amount of tooth movement was reduced in all receptor-treated groups by approximately 50 per cent. At the same time, the number of TRAP-positive cells on the desmodontal bone surface and on the surface of the roots was reduced. Thus, systemic application of soluble receptors to IL-1 and TNF-alpha following experimental induction of tooth movement in the rat reduced the number of osteoclasts as well as odontoclasts. (+info)
In vitro evaluation of the thermal alterations on the root surface during preparation with different Ni-Ti rotary instruments.
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The present study evaluated, in vitro, the temperature alterations on the external root surface during instrumentation with four different rotary systems. A total of 20 extracted human maxillary lateral incisors were instrumented using either the ProFile, MicroMega, Quantec or K3 systems and the thermal alterations on the root surface were recorded by means of three thermocouples attached to the coronal, middle and apical portions of the root. Mean temperature increases no higher than 0.4 degrees C +/- 1.0 degrees C (ProFile system) were recorded, which indicates that these instruments are safe for the surrounding periodontal tissues. (+info)
Biometric study of furcation area of first maxillary molars.
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The present investigation was designed to study the distance from the 3 bifurcation entrances to their opposite roots, and also the virtual center of the trifurcation (TC), which is equidistant from each bifurcation entrance, of maxillary molars. Thirty-five teeth devoid of any surface damage or fused roots were selected. Roots were included in acrylic resin and cross-sectioned at the cementoenamel junction to the apex using a rotary diamond blade and 0.45-mm slices were obtained. A profile projector apparatus was used to obtain the coordinated points on a Cartesian plane, which allowed the calculation of all distances present using analytic geometric formulas. Based on statistical analysis (comparison by Kruskal-Wallis ANOVA test, p<0.05), the following results were obtained: 1) mean distance from the buccal furcation reaching the palatal root was 6.72 +/- 0.99 mm (range 4.73-8.67 mm); 2) mean distance from the mesial and distal furcations to the distal and mesial roots were 5.42 +/- 0.83 mm (range 3.78-7.07 mm) and 5.90 +/- 0.87 mm (range 4.18-7.59 mm), respectively. All means were determined up to the point of 1.40 mm from each bifurcation opening; 3) mean distance of TC was 4.26 +/- 0.42 mm (range 3.44-5.08 mm) for all levels. (+info)
Evaluation of the implantation position of mini-screws for orthodontic treatment in the maxillary molar area by a micro CT.
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The interalveolar septum between the upper first molar and the second premolar of the separated human maxillary bone was three-dimensionally observed by micro CT to evaluate the appropriate mini-screw type implant placement position by considering the relationship between the tooth roots and the maxillary sinus. After taking micro CTs of 5 human maxillary bones, horizontally sectioned images of the interalveolar septum area 2, 4, 6, 8, 10, and 12 mm deep from the crest of the alveolar ridge were reconstructed by three-dimensional reconstruction software. The bucco-lingual and mesio-distal lengths and area in each sectioned interalveolar septum were measured using digital image measurement software. Using the results, the interalveolar septum area between the upper first molar and the second premolar approximately 6-8 mm deep from the alveolar crest in the tooth root apical direction was determined to be the safest position for mini-screw implantation. Furthermore, lateral implantation from the palatal side was deduced to be the safest approach. (+info)