Periodontal status following surgical-orthodontic alignment of impacted central incisors with an open-eruption technique.
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Several factors may affect the outcome of the orthodontic/surgical modality for the resolution of impacted central incisors, but particularly the manner in which the impacted tooth is exposed. The present study aimed to evaluate the post-retention clinical appearance and periodontal status of impacted maxillary central incisors which were exposed and aligned with an open-eruption surgical-orthodontic technique. Twelve subjects (four males, eight females), aged 22 years (range 15-38 years), previously treated for a unilateral impacted central incisor (ICI), were examined 10 years (range 3-25 years) post-retention. A split-mouth method was used for the comparison with the unaffected side. One treated central incisor exfoliated 10 years post-retention, thus the results were based on the remaining 11 patients. Statistically significant differences were found between the affected and control incisors in most of the periodontal parameters measured, although some were small and of minimal clinical importance. The increase in the mesio-labial pocket depth was associated with a highly significant 10 per cent reduction in bone level at this site (P = 0.007). A highly statistically significant increase in crown length (P < 0.001) and a reduction in the width of the attached gingiva (P = 0.005) were seen in these previously impacted teeth. An abnormal gingival contour was present in eight treated incisors and positional relapse in five cases. It is concluded that the convenience of the open-eruption technique must be weighed against the long-term negative aesthetic and periodontal effects on the treated tooth, although the findings of this study should be viewed with caution due to the limited sample size. (+info)
A comparison of mesio-distal crown dimensions of the permanent teeth in subjects with and without fluorosis.
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This investigation was undertaken to compare the mesio-distal crown dimensions of the permanent teeth in subjects with and without fluorosis. For this study, 25 pairs of study models cast immediately from alginate impressions of children from each of the two groups were evaluated. Their mean ages were 13.9 +/- 1.6 and 13.9 +/- 1.4 years, respectively. A dental vernier calliper was used to record the maximum mesio-distal dimensions. Analysis of the study models showed that there were no statistically significant differences between the left and right sides (P > 0.05). The results indicated that the mesio-distal crown diameters were consistently larger in the subjects with non-fluorotic permanent teeth. With the exception of the mandibular first premolars, there were no statistically significant differences in the mesio-distal crown diameters of the two groups. (+info)
The influence of orifice sealing with various filling materials on coronal leakage.
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The aim of this study was to evaluate the sealing ability of materials filled in the orifice after root canal treatment. A total of 100 root canal-treated teeth were divided into six experimental groups: 1, Protect Liner F (PL); 2, Panavia F (PF); 3, DC core-Light cured (DCL); 4, DC core-Chemically cured (DCC); 5, Super-EBA (SE); 6, Ketac (KC). The materials were filled--to a depth of 4 mm--in the coronal part of the root canals, and evaluated for microleakage. The number of teeth that failed to stop dye penetration in the filled materials differed statistically between PL and DCL or SE or KC, PF and SE or KC, DCC and KC, DCL and KC. The mean distance of dye penetration differed significantly between PL and SE or DCC, PF and SE or DCC. Hence, these results indicated the advantageous sealing ability of adhesive and flowable materials. (+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)
Orthodontic extrusion: periodontal considerations and applications.
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Human teeth erupt naturally to compensate for tooth wear and tear. When a subgingival lesion such as crown fracture occurs, the general practitioner must consider orthodontic extrusion of the tooth to allow for prosthetic rehabilitation. However, because this therapeutic approach is not appropriate in all cases, each tooth must be carefully analyzed before treatment. The amount of force applied depends on the desired effect. Orthodontic extrusion can also be used to augment bone and tissue in the course of preparing an implant site. In most cases, endodontic treatment must be completed first, with close attention being paid to the contour of the final restoration. The benefits of extrusion are clear, but patients must nonetheless be informed of the disadvantages. (+info)
An unusual morphological anomaly in an incisor crown. Anterior dens evaginatus.
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Exophytic growth of a portion of the tissue structure is one of the various clinical manifestations of the morphological anomalies that can affect the crown of the anterior teeth. The crown form disorder presented in this paper consists of an asymptomatic bulge on part of the vestibular surface of the tooth, due to enamel and dentine growth, with no radiological evidence of the pulp having extended into the protrusion of mineralised tissues. In this case, it only affects one tooth and is not associated with any other dental morphology or structure disorder, or with any of the syndromes that have been described in association with this anomaly. The term to describe this situation in the anterior teeth is not clearly defined in the relevant literature, which employs various names such as talon cusp, accentuated cingulum (when it affects the lingual or palatal surface) or dens evaginatus (evaginated tooth, evaginated odontome), the term that is always used when it is present in the posterior teeth. (+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)
Chlorhexidine-modified glass ionomer for band cementation? An in vitro study.
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OBJECTIVE: To compare the mean retentive strength, predominant site of band failure, amount of cement remaining on the tooth at deband and survival time of orthodontic micro-etched bands cemented with chlorhexidine-modified (CHXGIC) or conventional glass ionomer cement (GIC). DESIGN: In vitro study. SETTING: Dental Materials Laboratory. MATERIALS AND METHODS: One-hundred-and-twenty intact, caries-free third molars were collected from patients attending for third molar surgery. These were stored for 3 months in distilled water and decontaminated in 0.5% chloramine. To assess retentive strength, 80 teeth were randomly selected and 40 were banded with each cement. Testing was undertaken using a Nene M3000 testing machine at a cross-head speed of 1 mm/min. Following debanding, the predominant site of failure was recorded as cement-enamel or cement-band interface. The amount of cement remaining on the tooth surface following deband was assessed and coded. Survival time for another 40 banded specimens, 20 cemented with each cement, was assessed following application of mechanical stress in a ball mill. MAIN OUTCOME MEASURES: Retentive strength, predominant site of failure, amount of cement remaining on the tooth surface, survival time. RESULTS: Mean retentive strength for bands cemented with CHXGIC (0.32 MPa, SD 0.09) or GIC (0.28 MPa, SD 0.07) did not differ significantly (p=0.05). All bands failed at the enamel-cement interface. There was no significant difference in the amount of cement remaining on the tooth surface after deband for each cement type (p=0.23). The mean survival time of bands cemented with CHXGIC or GIC was 7.0 and 6.4 hours, respectively (p=0.23). CONCLUSIONS: There was no significant difference in mean retentive strength, amount of cement remaining on the tooth after deband or mean survival time of bands cemented with CHXGIC or GIC. Bands cemented with either cement failed predominantly at the enamel-cement interface. The results suggest that CHXGIC may have comparable clinical performance to GIC for band cementation. (+info)