Advanced platelet-rich-fibrin (A-PRF +) has no additional effect on the healing of post-extraction sockets of upper third molars. A split mouth randomized clinical trial.

PURPOSE: This study evaluated the effects of advanced platelet-rich fibrin (A-PRF +) on the healing of upper third molar post-extraction sockets. METHODS: Sixteen patients who underwent extractions of the upper third molars (18 and 28) were included in this randomized split-mouth study. The alveoli on the test side were filled with A-PRF + , while the control side was maintained with blood clot. The side that received treatment was randomly defined. Alveolar bone regeneration was evaluated by CBCT scans to assess healing stage, bone density, and fractal analysis 1 week and 90 days post-extraction. Additionally, pain, edema, bleeding, and soft tissue alveolar repair were evaluated by clinical analyses 3, 7, 14, 30, and 90 days after the surgical procedure using a visual analog scale. RESULTS: There were no clinical differences regarding treatments in any experimental period. In the tomographic evaluation, at 7 days, the alveoli treated with A-PRF + presented a suggestive sign of higher bone density than the control alveoli, which was not confirmed 90 days after the surgical procedure. CONCLUSION: Thus, the use of A-PRF + does not demonstrate a clinical advantage in the repair of post-extraction sockets of upper third molars.

Definition of the Region of Interest for the Assessment of Alveolar Bone Repair Using Micro-computed Tomography.

The objective of this study was to evaluate the influence of the extraction socket (distal or lingual root) and the type of region of interest (ROI) definition (manual or predefined) on the assessment of alveolar repair following tooth extraction using micro-computed tomography (micro-CT). The software package used for scanning, reconstruction, reorientation, and analysis of images (NRecon®, DataViewer®, CT-Analyzer®) was acquired through Bruker < https://www.bruker.com > . The sample comprised the micro-CT volumes of seven Wistar rat mandibles, in which the right first molar was extracted. The reconstructed images were analyzed using the extraction sockets, i.e., the distal and intermediate lingual root and the method of ROI definition: manual (MA), central round (CR), and peripheral round (PR). The bone volume fraction (BV/TV) values obtained were analyzed by two-way ANOVA with Tukey's post hoc test (α = 5%). The distal extraction socket resulted in significantly lower BV/TV values than the intermediate lingual socket for MA (P = 0.001), CR (P < 0.001), and PR (P < 0.001). Regarding the ROI, when evaluating the distal extraction socket, the BV/TV was significantly higher (P < 0.001) for MA than for CR and PR, with a lower BV/TV for CR. However, no significant difference was observed for MA (P = 0.855), CR (P = 0.769), or PR (P = 0.453) in the intermediate lingual extraction socket. The bone neoformation outcome (BV/TV) for alveolar bone repair after tooth extraction is significantly influenced by the ROI and the extraction socket. Using the predefined method with a standardized ROI in the central region of the distal extraction socket resulted in the assessment of bone volume, demonstrating the most critical region of the bone neoformation process.

Effect of the association of infra-red and red wavelength photobiomodulation therapy on the healing of post-extraction sockets of third lower molars: a split-mouth randomized clinical trial.

The aim of this study was to evaluate the effect of photobiomodulation therapy (PBMT) with the association of red and infra-red laser therapy in the healing of the post-extraction sockets of third lower molars. Twenty patients were submitted to extraction of lower third molars and the post-extraction sockets were treated using two different approaches in a randomized split-mouth design: The test side received the PBMT with red (λ 660 nm) and infra-red laser therapy (λ 808 nm) and the control side was not irradiated. The PBMT was applied immediately and 3 and 7 days after the surgical procedure. Post-extraction socket healing was assessed by the bone repair score, bone density, and fractal dimension analysis 7 and 90 days after the surgical procedure, using cone-beam computed tomography images. Additionally, clinical analyses were performed 3, 7, 14, 30, and 90 days after the surgical procedure, considering the occurrence of pain, edema, and bleeding, as well as the quality of the oral mucosa repair, assessed using a visual analogue scale. The clinical analysis showed that PBMT reduced edema and improved the repair of oral mucosa at 7 days after surgery, while the tomographic analysis showed no significant differences between groups. Dual-wavelength PBMT improved the post-operative clinical course in patients undergoing lower third molar extraction, without altering bone repair.

Biological parameters, discolouration and radiopacity of calcium silicate-based materials in a simulated model of partial pulpotomy.

AIM: To analyse the discolouration, radiopacity, pH and calcium ion release of Biodentine (BD), Bio-C repair (BCR) and Bio-C temp (BCT), as well as their biological effects on human dental pulp cells (hDPCs). METHODOLOGY: Sixty-four extracted bovine incisors were prepared to simulate crown fractures with pulp exposure and open root apex. The roots were filled using a mixture of agar and blood (control), and BD, BCR or BCT were placed over this mixture. Colour assessment analyses of the samples were performed before and immediately after material insertion and repeated at 30 and 90 days, using a spectrophotometer. The colour change of each specimen was evaluated at the crown and calculated based on the CIELab colour space. Digital radiographs were acquired for radiopacity analysis. hDPCs were placed in contact with different dilutions of culture media previously exposed to such materials and tested for cell viability using the MTT assay. The pH and calcium ion release of all materials were measured after 24 h; the data were assessed using one-way analysis of variance (ANOVA). Cell viability was analysed by two-way ANOVA. Differences in colour parameters and wound-healing data were assessed by two-way repeated measures ANOVA (α = 0.05). Tukey's and Dunnett's tests were used to compare the experimental groups with the control group. RESULTS: BCR had grater radiopacity and smaller colour alteration (ΔEab/ΔE00) than the other materials tested (p < .005; p < .001). No significant differences in pH were found amongst the tested materials (p > .05). BCT was associated with the largest release of calcium ions (p < .0001). BD had cell viability similar to that of the control at the lowest dilutions, and BCR was similar to that of the control, regardless of the dilution tested (p > .05). BCT had a lower percentage of viability than that of the control at all tested dilutions (p < .0001). Cell migration rates in BD and BCR were similar to those in the control group after 24 h and 48 h (p > .05), whilst BCT had larger voids than the control in both periods (p < .0001). CONCLUSIONS: BCR, BCT and BD were associated with tooth discolouration. BCR had the lowest staining values, the highest radiopacity and viability greater than 80% hDPCs.

Comparison of different methods to assess alveolar cleft defects in cone beam CT images.

OBJECTIVES: This study aimed to evaluate the accuracy of three different methods for assessing the volume of cleft defects in CBCT images. The influence of field of view (FOV) and voxel sizes was also assessed. METHODS: Using three radio-opaque plastic skulls, unilateral defects were created to mimic alveolar clefts and were filled with wax following the contralateral side contours. They were scanned in a CBCT unit using four different acquisition protocols, varying FOV and voxel sizes. Using three different methods, the defect/wax volume was evaluated on the images by defining: (1) the width, height and facial-palatal length of the defect in maximum intensity projection; (2) the areas of the defect on axial slices; and (3) the threshold and segmentation of the region of interest. The values obtained from each method using different acquisition protocols were compared with the real volume of the wax (gold standard) using ANOVA and Tukey's test. RESULTS: Methods 2 and 3 did not differ from the gold standard (p > 0.05). Conversely, Method 1 presented statistically significant overestimated values (p < 0.01). No differences were found among the different FOV and voxel sizes (p > 0.05). CONCLUSIONS: CBCT volumes proved reliable for the volumetric assessment of alveolar cleft defects, when using Methods 2 and 3 regardless of FOV and voxel sizes. It may be possible to improve surgical planning and outcomes by knowing the exact volume of grafting material needed prior to the surgical intervention.

Micro-CT evaluation of the radioprotective effect of resveratrol on the mandibular incisors of irradiated rats

Abstract The purpose of this study was to perform a microcomputed tomographic evaluation of the radioprotective effect of resveratrol on the volume of mandibular incisors of irradiated rats. A second aim was to make a quantitative assessment of the effect of x-ray exposure on these dental tissues. Twenty adult male rats were divided into four groups: control, irradiated control, resveratrol, and irradiated resveratrol. The resveratrol groups received 100 mg/kg of resveratrol, whereas the irradiated groups were exposed to 15 Gy of irradiation. The animals were sacrificed 30 days after the irradiation procedure, and their mandibles were removed and scanned in a microcomputed tomography unit. The images were loaded into Mimics software to allow segmentation of the mandibular incisor and assessment of its volume. The results were compared by One-way ANOVA and Tukey's post hoc test, considering a 5% significance level. The irradiated groups showed significantly diminished volumes of the evaluated teeth, as compared with the control group (p < 0.05). The resveratrol group presented higher values than those of the irradiated groups, and volumes similar to those of the control group. High radiation doses significantly affected tooth formation, resulting in alterations in the dental structure, and thus lower volumes. Moreover, resveratrol showed no effective radioprotective impact on dental tissues. Future studies are needed to evaluate different concentrations of this substance, in an endeavor to verify its potential as a radioprotector for these dental tissues.

Three-dimensional evaluation of nasopharyngeal airways of unilateral cleft lip and palate patients.

OBJECTIVES/HYPOTHESIS: The aim of this study was to compare the volume of nasopharyngeal airways of patients with unilateral cleft lip and palate (UCLP) with a control (noncleft) group of subjects. STUDY DESIGN: Retrospective case-control study. METHODS: The sample consisted of 45 subjects, 30 with UCLP who underwent cone beam computed tomography (CBCT) exams as part of their workups for alveolar bone graft and 15 noncleft subjects seeking orthodontic care who obtained CBCT for diagnostic purposes. The three-dimensional volumes of nasal (NV) and oropharyngeal (PV) airways of these subjects were assessed separately using Mimics software by one well-calibrated evaluator. The images were rendered, and the volumes were measured in cm(3). RESULTS: The mean PV of the UCLP subjects was 6.7 cm(3) and the mean NV was 10.3 cm(3). The control group presented with a mean PV of 8.1 cm(3) and a mean NV of 11.6 cm(3). Student t test showed no statistically significant difference for PV (P = 0.10) or NV (P = 0.23) when comparing cleft and noncleft subjects. CONCLUSION: Evaluation of the nasopharyngeal airways revealed that the NV and PV airways showed no difference between the cleft and noncleft subjects. It is interesting to postulate that the reported nasal abnormalities of the cleft patients do not produce a significant measurable effect on the overall volume, at least as shown in our study sample. In addition, the nasopharyngeal airways of patients are not larger than those of age-matched controls, at least at the ages that were sampled, after cleft palate repair.

Vertical measurements for planning palatal mini-implants in lateral radiography and cone beam computed tomography.

OBJECTIVE: To compare palatal bone height measurements in the region of first premolars for planning palatal mini-implant insertion on conventional lateral radiography (CLR), cone beam computed tomography (CBCT), and reformatted virtual lateral radiography (VLR). MATERIALS AND METHODS: One hundred ten images of CLR, VLR, and CBCT from the same patient were used. Linear measurements corresponding to the relevant dimension of available bone on upper first premolar site were performed between the hard palate floor and the nasal floor. The Friedman test compared the measurements of all imaging modalities. Intraobserver and interobserver agreement was calculated with the intraclass correlation coefficient (ICC). RESULTS: The ICC values showed excellent intraobserver and interobserver agreement. VLR examination resulted in measurements statistically different from both CBCT and CLR images (P < 0.05), being underestimated when compared with these techniques, and the values found on CLR did not show statistically significant differences from the CBCT images (P > 0.05). CONCLUSIONS: The measurements for planning palatal mini-implants at the level of first premolars are comparable on CLR and multiplanar reconstructions of CBCT, whereas underestimated in reformatted examinations (VLR).

Accuracy of digital panoramic radiography in the diagnosis of temporal bone pneumatization: a study in vivo using cone-beam-computed tomography.

PURPOSE: The objective of the study was to determine the diagnostic accuracy of panoramic radiographs in the evaluation of pneumatization of the temporal bone, with confirmation of the diagnosis by cone-beam-computed tomography (CBCT) images. METHODS: Images of 200 patients' digital panoramic radiographies and CBCT were examined by three evaluators regarding the presence or absence of pneumatization on temporomandibular joint (TMJ) fossa and/or articular eminence. When present, the defect was classified as uni- or multilocular, and as unilateral or bilateral. Areas under the ROC curve were compared to assess the accuracy of panoramic radiograph. RESULTS: The values obtained in the comparisons ranged from Az = 0.67 to 0.55 (Az = area under the ROC curve). CONCLUSIONS: The panoramic radiograph, is not the exam of choice for detecting the presence of these air cells based on its medium to low accuracy for diagnosis of pneumatized articular eminence and TMJ fossa when compared to CBCT.

Tomografia por emissão de pósitrons em tumores malignos de cabeça e pescoço / Positron-emission tomography in head and neck cancer

Head and neck cancer is considered a public health problem worldwide, given its high morbidity and mortality. The more advanced is the histopathologic grade, the more aggressive may be the therapies. The development of health policies, diagnosis and treatments lead to better prognostic perspectives. This paper aimed to review the literature regarding the application of positron emission tomography in headand neck cancer, including its impact in the diagnosis, image principles, radiotracers, positron emission tomography / computed tomographyimage fusion and other advantages. The review was performed following systematized search strategies reported in the literature. It could be observed that the use of positron emission tomography improves the diagnostic approach of the patients, especially when positron emission tomography is allied to computed tomography. As it provides physiological information, positron emission tomography also benefits the prognostic and reduces the morbidity related to the treatment of head and neck cancer.

Apresentando-se como um problema de saúde pública em todo o mundo, o câncer de cabeça e pescoço caracteriza-se por sua alta morbidadee mortalidade. Quanto mais avançado o grau de diferenciação tumoral, mais mutiladoras tendem a ser as terapias empregadas. Desta forma,os avanços nos âmbitos da promoção de saúde, diagnóstico e tratamento são extremamente benéficos ao prognóstico. Esta revista daliteratura tem por objetivo discorrer sobre a aplicação da tomografia por emissão de pósitrons no diagnóstico e planejamento terapêuticode pacientes portadores de tumores malignos de cabeça e pescoço, princípios de formação da imagem, radiofármacos utilizados, fusãode imagens tomografia por emissão de pósitrons e tomografia computadorizada e suas contribuições. O levantamento bibliográfico foiefetuado segundo estratégias sistematizadas relatadas em literatura. Fornecendo informações relativas à fisiologia das lesões através daadministração de radiofármacos, pode ser observado que a tomografia por emissão de pósitrons, especialmente quando aliada à tomografiacomputadorizada, maximiza as possibilidades diagnósticas em determinadas indicações, favorecendo ao prognóstico e sugerindo redução na morbidade decorrente do tratamento no câncer de cabeça e pescoço.