Vania Regina Camargo Fontanella

Deep caries lesions after incomplete dentine caries removal: 40-month follow-up study.

Radiographic changes after indirect pulp capping (32 teeth in 27 patients) were studied for up to 36–45 months. Radiolucent zone (RZ) depth and tertiary dentine formation were assessed qualitatively and changes in radiographic density (by image subtraction) in RZ and control areas (CA) were estimated. During follow-up there were 1 pulp necrosis, 1 pulp exposure, 3 fractures and 3 withdrawals. Twelve cases showed decreased RZ depth and 4 displayed tertiary dentine. No changes with time in density of CA or RZ, or in the difference between them, were observed. It is concluded that indirect pulp capping arrests lesion progression, suggesting that complete dentine caries removal is not essential for caries control.

Qualitative and quantitative radiographic assessment of sealed carious dentin: a 10-year prospective study

OBJECTIVE The objective of this study was to assess radiographic outcomes after partial carious dentin removal performed in deep caries lesions over a 10-year period. STUDY DESIGN Baseline image was compared to 3 follow-up radiographs (at 6-7 months, 3 years, and 10 years). Tertiary dentin deposition and lesion depth were qualitatively assessed. Radiographic density changes in the radiolucent zone (RZ) beneath the restoration were quantitatively compared to the control areas (CA) using digital subtraction radiography (Friedman repeated-measures analysis of variance). RESULTS A total of 13 teeth were evaluated. In most cases, lesion depth remained unchanged or decreased (12/13) and tertiary dentin formation was observed (10/13) after the 10-year follow-up. Differences between RZ and CA at the 6- to 7-month and 3-year follow-up periods were similar but significantly lower than those at the 10-year assessment. CONCLUSIONS Sealing of carious dentin arrested the caries process, promoted deposition of tertiary dentin, and induced mineral gain in the radiolucent zone.

The monitoring of deep caries lesions after incomplete dentine caries removal: results after 14–18 months

This paper aims to assess radiographic changes after incomplete carious dentine removal and tooth sealing. Thirty-two teeth with deep caries lesions were studied. The treatment consisted of incomplete excavation, application of a Ca(OH)2 layer, sealing temporarily for a 6- to 7-month period and then restoration. Standardised bitewing radiographs were taken immediately after the temporary sealing and at 6- to 7- and 14- to 18-month intervals. The digitised images were analysed blind by image subtraction. The quantitative analyses subtractions were performed in the radiolucent zone (RZ) beneath the restoration and in two adjacent control areas (CA). Two cases were lost during the 6- to 7-month period (one pulp necrosis and one pulp exposure during removal of the provisional sealing). No difference (p>0.05) was observed in the radiographic density of the CA and the RZ in the two experimental periods. The mean and standard deviation (grey tonalities scale) were 129.42±5.83 and 127.65±4.67 (control areas) and 132.96±7.41 and 132.90±5.99 (RZ) for the first and second experimental periods, respectively. The radiographic density of the CA differed from the RZ (Tukey test, p<0.001). Interference in environmental conditions by partial dentine caries removal and tooth sealing arrests lesion progression, suggesting that complete dentine caries removal is not essential to control caries progression.

Apical Transportation: A Comparative Evaluation of Three Root Canal Instrumentation Techniques with Three Different Apical Diameters

This study conducted an in vitro analysis of the level of apical transportation in mesiobuccal roots of upper molars after manual instrumentation with stainless steel files, preparation with the K3 system, and with a reciprocating NSK handpiece. Sixty roots were mounted in muffles and then longitudinally sectioned. A digital image was acquired of the inner surface of one root half. After instrumentation, the inner surfaces of the same root halves were digitized with file sizes #30, #35, and #40. Each image obtained was superimposed over the corresponding preoperative image, and the apical transportation was measured. The Friedman and Wilcoxon tests were used to compare results for the file sizes, and comparison of the groups was made with the Kruskal-Wallis test, demonstrating statistically significant differences (P = .000). The stainless steel file sizes #35 and #40 caused significant apical transportation, and K3 system proved safe for apical preparation, with little deviation.

Analysis of apical root transportation associated with ProTaper Universal F3 and F4 instruments by using digital subtraction radiography.

INTRODUCTION The aim of this study was to assess the occurrence of apical root transportation after the use of ProTaper Universal rotary files sizes 3 (F3) and 4 (F4). METHODS Instruments were worked to the apex of the original canal, always by the same operator. Digital subtraction radiography images were produced in buccolingual and mesiodistal projections. A total of 25 radiographs were taken from root canals of human maxillary first molars with curvatures varying from 23-31 degrees. Quantitative data were analyzed by intraclass correlation coefficient and Wilcoxon nonparametric test (P = .05). RESULTS Buccolingual images revealed a significantly higher degree of apical transportation associated with F4 instruments when compared with F3 instruments in relation to the original canal (Wilcoxon test, P = .007). No significant difference was observed in mesiodistal images (P = .492). CONCLUSIONS F3 instruments should be used with care in curved canals, and F4 instruments should be avoided in apical third preparation of curved canals.

Ytterbium trifluoride as a radiopaque agent for dental cements

AIM To evaluate the radiopacity, degree of conversion (DC) and flexural strength of an experimental dental cement, with several added radiopaque substances. METHODOLOGY Titanium dioxide, quartz, zirconia, bismuth oxide, barium sulphate and ytterbium trifluoride were added to the experimental cement in five different concentrations. Radiopacity was evaluated with a phosphor plate system, and the radiodensity of specimens was compared with an aluminium step-wedge. DC was evaluated with FT-infrared spectroscopy following 20 s of photo-activation. Specimens with dimensions of 12 x 2 x 2 mm were used for the flexural strength test. Data were analysed with two-way anova and Tukeys post hoc test. RESULTS Radiopacity of the experimental dental cements with barium sulphate and bismuth oxide at 40% and ytterbium fluoride at 30% and 40% showed no significant differences in comparison with 3 mm of Al (181, 96). CONCLUSIONS The experimental dental cements with at least 30% added ytterbium trifluoride had satisfactory radiopacity without influencing other properties.

Comparação de índices morfométricos obtidos na radiografia odontológica panorâmica na identificação de indivíduos com osteoporose/osteopenia

OBJECTIVE: The present study was aimed at comparing indices obtained from dental panoramic radiographs with bone densitometry results in the identification of individuals affected by osteoporosis/osteopenia. MATERIALS AND METHODS: Panoramic mandibular, mental, antegonial, gonial and mandibular cortical indices calculated with basis on dental panoramic radiographs of postmenopausal women were compared with bone densitometry results, twice by one observer and once by a second observer. RESULTS: Significant differences were not found between the two measurements performed by the same observer, except for the antegonial index on the left side. Interobserver agreement for both sides was good. The variance analysis demonstrated statistically significant differences among groups (normal, osteopenia and osteoporosis) for all the indices evaluated. Differences were significant among all mean panoramic mandibular and mental indices. On the other hand, for the antegonial and gonial indices, only the normal group presented higher means as compared with the other groups (osteopenia and osteoporosis) which did not differ between themselves. CONCLUSION: The indices evaluated were reproducible; panoramic mandibular and mental indices presented the highest sensitivity in the detection of osteopenia/osteoporosis, however the panoramic mandibular index specificity was low. Although all the indices evaluated could identify low bone density, only the panoramic mandibular and mental indices could differentiate patients affected by osteopenia/osteoporosis.

Apical Root Canal Transportation and Remaining Dentin Thickness Associated with ProTaper Universal with and without PathFile

INTRODUCTION This study aimed to compare, using digital subtraction radiography, apical transportation in mesiobuccal root canals of extracted human maxillary molars instrumented with ProTaper Universal F3 and F4 files (Dentsply Maillefer, Ballaigues, Switzerland) with and without the prior creation of glide paths using the PathFile system and to compare, using cone-beam computed tomographic imaging, remaining dentin thickness (RDT) after complete preparation. METHODS Forty mesiobuccal roots with curvatures of 20°-35° were used. In group A, glide paths were created with PathFile #1, #2, and #3 to the working length; in group B, no glide paths were used. All canals were instrumented up to F4 to the working length. Digital subtraction radiographic images were obtained in buccolingual and mesiodistal directions. Apical transportation associated with F3 or F4 was calculated based on the difference between the tip of the first and the last instrument analyzed in each group. RDT was calculated based on cone-beam computed tomographic images. RESULTS Apical transportation was higher after F4 regardless of the use of the PathFile system. No statistically significant differences between groups A and B were observed in apical transportation after instrumentation with F3 or F4 (P > .05). Group A showed greater RDT values at 2 (buccal and mesial walls, P < .05) and 3 mm (buccal and distal walls, P < .05) from the apex but not at 1 mm. CONCLUSIONS The use of the PathFile system before root canal preparation with ProTaper Universal F3 and F4 did not influence apical transportation but was associated with greater RDTs at 2 and 3 mm from the apex.

In vitro evaluation of a method for obtaining periapical radiographs for diagnosis of external apical root resorption

This in vitro study was conducted to evaluate a method to obtain reproducible periapical radiographs, using individualized positioning devices, of upper central incisors submitted to simulated orthodontic movement. Linear measurements of tooth length were carried out on 29 extracted human central incisors. The teeth were radiographed in a tissue simulator, at different inclinations in the bucco-lingual direction (0 initial, 0 control, -10, -5, +5, and +10 degrees). The radiographs were digitized and quantitative analysis of tooth length was carried out using an electronic ruler. The linear measurements of tooth length were reproducible (r = 0.99) for repeated measurements as well as in the comparison of the initial and control images at 0 degree, where measurements did not differ significantly (analysis of variance, P = 0.827) in radiographs with different angulations. These results show that the method proposed for obtaining in vitro periapical radiographs results in reproducible images of tooth length, even when orthodontic movement is simulated by inclination of the tooth up to 20 degrees in the bucco-lingual direction.

Evaluation by digital subtraction radiography of induced changes in the bone density of the female rat mandible.

OBJECTIVES To verify whether changes in bone mass induced by glucocorticoid and bisphosphonate can be detected by digital subtraction radiography of lateral X-rays in female rat mandibles. METHODS 36 Rattus norvegicus (Wistar) females were randomly allocated to three groups: Group 1, control (n = 12); Group 2, induced osteopaenia (n = 12); and Group 3, induced osteopaenia plus risedronate (n = 12). Group 1 received subcutaneous saline solution (2 ml kg(-1)) injections for 12 weeks. Group 2 received 1 mg kg(-1) methylprednisolone acetate for 12 weeks. Group 3 received the same treatment as Group 2, plus 3 mg kg(-1) risedronate sodium for a further 12 weeks. A radiograph of the left mandible was taken on day 0 and after 12 weeks. A third radiograph was taken in Group 3 after risedronate treatment. Digital subtraction of the radiographs was used to compare the intensity of pixels in the control area and the test area. The animals were killed and the same area assessed by subtraction was histologically evaluated. RESULTS ANOVA revealed statistically significant histological differences between the three groups. Tukeys multiple comparisons test showed that Group 2 had the smallest mean proportion of bone trabeculae per field and Group 3 the largest (F = 37.56; P < 0.01). Radiographic subtraction revealed a higher mean pixel intensity in Groups 1 and 3 vs Group 2. In Group 3, glucocorticoid caused a significant loss in radiographic density, and risedronate restored that loss (Friedmans non-parametric test). CONCLUSIONS Subtraction radiography was able to detect changes in bone mass induced by glucocorticoid and bisphosphonate.