https://repositorio.ufu.br/handle/123456789/5478 2026-08-11T11:08:41Z https://repositorio.ufu.br/handle/123456789/49403 Title: Avaliação multidimensional in vitro dos sistemas atuais de escaneamento intraoral: influência de diferentes condições no comportamento óptico, qualidade da malha e precisão da linha de término Abstract: This study performed a multidimensional in vitro assessment of commercially available intraoral scanning systems (IOS), investigating the optical behavior of the devices and the quality of the generated digital meshes. In Chapter 1, seven IOS in nine configurations were characterized for irradiance, emission spectrum, beam profile, and blue-light hazard potential under two ambient light conditions and four working distances. IOS identity was the dominant source of irradiance variance (85–86%; P<0.001), with four distinct spectral groups identified independently of acquisition technology. Irradiance decreased with working distance in all systems, with decay rates varying 4.3-fold, and ambient light significantly influenced seven of the nine configurations. Blue-light hazard weighted irradiance varied 139-fold across systems. In Chapter 2, ten IOS were used to scan a standardized mandibular typodont with a full crown preparation, with quantitative and qualitative (n=10) analysis of STL meshes. Significant differences were observed for all quantitative mesh parameters (P<0.001) and for finish line accuracy (P<0.001), with TRIOS 3 and TRIOS 5 achieving the highest scores. No correlation was found between tessellation quality and finish line accuracy, evidencing a dissociation between objective mesh metrics and clinically relevant perceptual outcomes. Integrated assessment of optical, quantitative, and qualitative parameters proved essential for evidence-based IOS selection in restorative digital workflows. Notes: Ao Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq - (N° 421484/2025-0), à Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG) e à Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES - 001), pelo apoio financeiro essencial à realização desta pesquisa. Este trabalho contou ainda com o suporte do CNPq por meio do INCT Saúde Oral e Odontologia (N° 406840/2022-9). Ao Ministério da Saúde, por meio da AgSUS, pelo financiamento concedido através dos Termos de Execução Descentralizada TED 088/25, TED 158/24 e TED 125/24, que viabilizaram parte fundamental deste trabalho. A bolsa de estudos e o suporte institucional recebidos foram determinantes para que esta pesquisa pudesse ser conduzida com a dedicação e o rigor que ela exige. 2026-07-10T00:00:00Z https://repositorio.ufu.br/handle/123456789/49388 Title: Análise fractal em imagens odontológicas: estudos comparativos entre modalidades de imagem e parâmetros de aquisição Abstract: Studies on fractal analysis have demonstrated its potential applicability across different areas of Dentistry. Although the structured protocol for its use in dental imaging was proposed more than twenty years ago, important gaps remain regarding the influence of imaging modality, acquisition parameters, image-processing methods, and the selection of regions of interest. In this context, the present dissertation had two objectives. The first was to compare different imaging modalities (panoramic radiography and panoramic reconstructions obtained from cone beam computed tomography with varying thicknesses) in the assessment of trabecular bone structure using fractal analysis. The second objective was to investigate the influence of milliampere settings, image-processing methods for fractal analysis, and regions of interest on fractal dimension values obtained from cone-beam computed tomography images, as well as to evaluate whether variations in these factors affect fractal dimension values. The first study evaluated images from 20 patients, including panoramic radiographs and panoramic reconstructions with different thicknesses (160 µm; 480 µm; 800 µm; 1.1 mm; 2.1 mm; 3 mm; 4 mm; 5 mm; 10 mm; 14.9 mm; 20 mm; 29.9 mm; 40.2 mm; and 50.1 mm). In each image, bilateral regions of interest were selected 2 mm superior, medial, and inferior to the mental foramen, and fractal dimension values were obtained using the White and Rudolph method. The results demonstrated differences between fractal dimension values obtained from panoramic radiographs and panoramic reconstructions, as well as between thinner reconstructions (160 µm and 480 µm) and thicker reconstructions (29.9 mm, 40.2 mm, and 50.1 mm). In the second study, eight edentulous human mandibles were evaluated using cone beam computed tomography with seven different milliampere settings (2, 4, 6.3, 8, 10, 12, and 15). Cross-sectional slices were selected in five regions of interest bilaterally (incisor, canine, premolar, first molar, and second molar), and fractal analysis was performed using three different image-processing methods (White and Rudolph, revised White and Rudolph, and the gray-scale method). The results indicated that fractal dimension values in tomographic images are significantly influenced by the image processing method used for fractal analysis but remain stable across variations in milliampere settings and regions of interest within the mandibular body. Overall, the findings of this dissertation demonstrate that fractal dimension is sensitive to specific methodological factors, reinforcing the need for standardization of the imaging modality and processing protocol for fractal analysis in longitudinal follow-up and when comparing patient data. 2026-07-09T00:00:00Z https://repositorio.ufu.br/handle/123456789/49334 Title: Perfil epidemiológico e impactos da osteonecrose dos maxilares induzida por medicamentos na qualidade de vida de usuários de antirreabsortivos e antiangiogênicos: um estudo observacional Abstract: Objective: This descriptive and analytical cross-sectional observational study aimed to evaluate the epidemiological aspects of medication-related osteonecrosis of the jaw (MRONJ) in patients using antiresorptive and antiangiogenic agents who were under care at a university oral medicine clinic from 2024 to 2026. Material and Methods: A convenience sampling method was used. A qualified data collection instrument was developed to collect epidemiological and clinicopathological data, along with the use of dental records for data collection and verification. A questionnaire on oral health-related quality of life and another related to general health were applied to all participants, respectively GOHAI and SF-36. Results: Forty participants were included, 31 without MRONJ and nine with MRONJ. The age range varied from 34 to 86 years, with the majority being female (67.50%), with incomplete primary education (32.50%) and complete secondary education (27.50%). Most participants presented multiple comorbidities and multiple medications for continuous use simultaneously, with metastatic bone disease, mainly due to multiple myeloma (30.00%) and breast cancer (32.50%). MRONJ prevalence was 22.5%. The most frequent location of MRONJ was the mandible (66.67%), in stages 1 (33.33%) and 2 (33.33%). Daily frequency of use of antiresorptive drugs (p=0.002), as well as the presence of active oral inflammation or infection (p=0.046), showed a statistically significant difference between groups. There were no statistically significant differences in the comparisons between groups for the GOHAI or SF36 scores, with moderate to low scores for both groups. Conclusion: This study sample presented factors of social vulnerability and high clinical complexity characterized by multimorbidity and polypharmacy. Based on the findings of this study, it is suggested that quality of life was possibly associated with the social and general health context rather than solely with MRONJ. 2026-07-08T00:00:00Z https://repositorio.ufu.br/handle/123456789/48948 Title: Efeitos dos métodos de desinfecção e esterilização em guias de corte impressos em resina 3d para ressecções maxilofaciais: estudo biomecânico e microbiológico in vitro Abstract: Objectives: This in vitro study evaluated the effect of the disinfection and sterilization methods on the microbiological efficacy, mechanical properties, and dimensional stability of 3D-printed surgical guides used in maxillofacial resections. Methods: Specimens were 3D-printed using an autoclavable resin (priZma 3D Bio Guide) and divided into four experimental groups: disinfection method: CHL, immersion in 0.12% chlorhexidine digluconate for 24 h; sterilization methods: STE, steam autoclave at 134 °C/5 min; HP, hydrogen peroxide plasma; CON, untreated control group. The microbiological growth using identification by MALDI-TOF-MS, flexural strength and elastic modulus by using three-point bending test, and dimensional stability by using digital photogrammetry with ImageJ® analysis were performed. Results: All experimental methods achieved total elimination of microorganisms (100%), differing significantly from the control group (75%). STE caused the most significant mechanical and dimensional changes on the 3D-printed resin, decreasing the flexural strength and increasing the elastic modulus. The use of CHL and HP preserved the dimensional stability, with CHL exhibiting the best dimensional stability in Δy and Δz (p<0.001). Macroscopic structural defects were observed when STE was used. Conclusion: Although all methods were microbiologically effective, autoclaving at 134 °C compromised the mechanical properties, dimensional stability, and caused structural defects in the 3D-printed resin. Hydrogen peroxide plasma sterilization provided the best balance between microbiological efficacy and preservation of the material's physical, dimensional, and fit characteristics, making it the most suitable method for heat-sensitive 3D-printed surgical guides. 2026-06-30T00:00:00Z