Similar glucose leakage pattern on smear-covered, EDTA-treated and BioPure MTAD-treated dentin

This study assessed the effect of BioPure MTAD on the sealing ability on the basis of the filtration rate of glucose along the root fillings. Both 17% ethylenediaminetetraacetic acid (EDTA) and smear-covered dentin were used as reference patterns to compare the results. Sixty-four human upper incisors were prepared with different irrigation protocols (n = 18): G1, NaOCl; G2, NaOCl + EDTA; and G3, NaOCl + BioPure MTAD. The teeth were obturated and then prepared in a double-chamber apparatus to evaluate the glucose leakage along the root fillings. The amount of glucose leakage was quantified with spectrophotometry at 7, 14, 21, 28, 35, 42, 49, and 56 days. Leakage existed in every sample and was variable in all of the experimental groups, and Kruskal-Wallis H test results showed that there were no significant differences among the experimental groups (P > .05). The smear-covered dentin did not allow more glucose leakage than EDTA-treated and BioPure MTAD-treated dentin.     

Dye extraction results on bacterial leakproof root fillings

This study was designed to assess and compare the sensitivity and sealability results between bacterial leakage and dye extraction. Eighty mandibular incisors were prepared, and their roots were filled as follows (n = 20): G1, lateral condensation; G2, System B; and G3, Thermafil system. All teeth were mounted in a 2-chamber apparatus, and the coronal access was exposed to human saliva for 100 days. The remaining bacterial leakproof specimens were randomly assigned to create 3 new and equal groups (n = 10). These bacterial leakproof specimens were submitted to a dye extraction setup. Each specimen was placed into a plastic vial with 5 mL of 2% methylene blue for 48 hours. After storage, the specimens were rinsed with tap water and dissolved in nitric acid. A sample of 100 microL of the supernatant from each specimen was analyzed in a UV-Visible spectrophotometer to determine the amount of methylene blue leakage. The log-rank test showed no significant difference in the bacterial leakage pattern among the groups (P > .05). In the dye extraction analysis, Kruskal-Wallis H test was unable to detect significant differences among all experimental groups (P > .05). The 3 filling techniques displayed similar leakage for both leakage models. Moreover, the present study demonstrated that all bacterial leakproof specimens leaked when submitted to the blue methylene extraction model.     

Surgical planning for resection of an ameloblastoma and reconstruction of the mandible using a selective laser sintering 3D biomodel

Ameloblastoma is a benign locally aggressive infiltrative odontogenic lesion. It is characterized by slow growth and painless swelling. The treatment for ameloblastoma varies from curettage to en bloc resection, and the reported recurrence rates after treatment are high; the safety margin of resection is important to avoid recurrence. Advances in technology brought about great benefits in dentistry; a new generation of computed tomography scanners and 3-dimensional images enhance the surgical planning and management of maxillofacial tumors. The development of new prototyping systems provides accurate 3D biomodels on which surgery can be simulated, especially in cases of ameloblastoma, in which the safety margin is important for treatment success. A case of mandibular follicular ameloblastoma is reported where a 3D biomodel was used before and during surgery.     

Histologic and ultrastructural analysis of regenerated bone in maxillary sinus augmentation using a porcine bone-derived biomaterial

BACKGROUND: The purpose of the present study was the histologic and ultrastructural evaluation of a biomaterial composed of cortical pig bone in the form of granules. METHODS: After maxillary sinus augmentation using this biomaterial, 10 specimens were retrieved after 5 months in 10 patients using this biomaterial. The specimens were processed to be observed under light microscopy (LM) and transmission electron microscopy (TEM). Histomorphometric measurements were presented by means +/- standard deviations. RESULTS: LM showed that most of the particles were surrounded by newly formed bone. In some areas, the osteoid matrix was present; however, mainly compact bone was present at the interface. There was no evidence of an acute inflammatory infiltrate. The newly formed bone was 36% +/- 2.8% and marrow spaces were 38% +/- 1.6%, whereas residual grafted material was 31% +/- 1.6%. Under TEM, all phases of bone formation (osteoid matrix, woven, and lamellar bone) were observed in proximity with the biomaterial particles. The bone-biomaterial interface showed a close contact between the porcine bone particles and the surrounding bone that had mainly features of mature bone with numerous osteocytes. A lamina limitans was sometimes present at this interface. CONCLUSIONS: According to our knowledge, this is the first study presenting data on TEM of a porcine bone-derived biomaterial used in sinus augmentation procedures in humans. Our findings show that this is a biocompatible biomaterial that can be used for maxillary sinus augmentation procedures without interfering with the normal reparative bone processes.     

Accuracy of Root ZX II in locating foramen in teeth with apical periodontitis: an in vivo study

Introduction

This study was conducted in vivo to investigate the accuracy of Root ZX II in locating the apical foramen in teeth with apical periodontitis (AP).

Methods

Twenty-seven single-root teeth scheduled for extractions were selected; in AP group, there were 12 teeth with pulp necrosis and radiographic evidence of apical lesions, and VT group consisted of 15 vital teeth. After endodontic access, the coronal portion of the canal was flared, and electronic measurement was performed by using a 15 K-file until the device level reading “APEX” was reached. The file was fixed in place, and the tooth was extracted. The apical third of the root was shaved until exposure of the file. The distance from the file tip to the most coronal border of the apical foramen was obtained.

Results

The mean distance in AP group was +0.117 (standard deviation, 0.373) and in VT group was -0.105 (standard deviation, 0.218). The unpaired t test showed no difference between the groups when comparing the mean distances (P > .05). The apical foramen was accurately located within ±0.5 mm in 83% of the teeth in AP group and in 100% of VT group. Statistical analysis showed no difference between the groups (P = .1092).

Conclusions

The Root ZX II device was accurate in locating the apical foramen regardless of the presence of AP.     

The effect of one session of supragingival plaque control on clinical and biochemical parameters of chronic periodontitis

Supragingival plaque control is a requisite for the success of any periodontal procedure. However, little is know about the effect of this procedure alone on periodontitis. The aim of this study was to determine the effect of supragingival plaque control on clinical and biochemical parameters of chronic periodontitis. Twenty-five subjects exhibiting at least 4 pockets > 5mm, non-smokers and with no relevant systemic diseases, were selected for the study. The clinical and biochemical assessments were done before and 21 days after removal of plaque retentive factors, extraction of affected teeth and instruction in oral hygiene. The statistical analysis was done with the Student paired t-test (p<0,05) and demonstrated a reduction on the percentage of sites with bleeding on probing from 42.72 ± 15.83 to 35.87 ± 13.30 (p=0.002). Reduction in probing depth was detected on anterior teeth (initial/final mean: 2.88 mm/2.78 mm; p=0.01) and interproximal sites (initial/final mean: 3.80 mm/3.65 mm; p=0.001). There was an increase from 66.81% to 68.65% in the number of sites with probing depth of 1 to 3mm and a decrease from 26.21% to 24.17% in those with probing depth of 4 to 6mm. The BAPNA results showed a decrease from 51.44 ± 20.78 to 38.64 ± 12.34 (p=0.04). This study demonstrated that supragingival plaque control provides a reduction in gingival inflammation and alterations in the subgingival microflora detected by the BAPNA test.     

Different diagnostic tools for the localization of impacted maxillary canines: clinical considerations

In this study we evaluated different radiographic exams for the localization of impacted maxillary canines (orthopantomography (OPT), laterolateral and posteroanterior teleradiography, parallax method, laterolateral, occlusal radiography, computerized axial tomography, cone beam CT) highlighting the advantages and disadvantages of each. Four patients with impacted maxillary canines underwent selected radiographic investigations which allowed us to discuss their potential in identifying the position relative to the impacted teeth in the upper jaw. It was not possible to carry out all methods on the same patient as the level of radiation exposure experienced by each patient would too high and therefore unethical. Each method revealed the position of the canine with respect to the adjacent structures and the inclination of the major axis of the impacted tooth with respect to the plane of reference. We then evaluated the ease of use, the dosage of radiation emitted, the significance of the localization of the impacted canine, the immediacy of availability of the information required and the cost of each method. Each technique presented intrinsic advantages and limitations; however CBCT provides elements which escape during traditional radiographic analysis and is therefore indicated in case of impacted teeth or cranio-facial structural anomalies.