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Objective: This prospective study is part of a randomised clinical trial and reports the changes in masticatory performance (MP) and bite force, and explores their influential factors, 1 year after the provision of mandibular overdentures retained by four titanium–zirconium mini implants. Methods: Edentulous patients received conventional complete dentures, followed by placement of four mini implants (Straumann® Mini Implant System) in the anterior mandible and converting the conventional prosthesis into a mandibular overdenture. Treatment protocols were randomised using a 2×2 factorial design combining different surgical (flapped vs. flapless) and loading (immediate vs. delayed) protocols. MP was assessed using a two‐colour mixing ability test and a colorimetric analysis to measure the level of colour mixing (Variance of Hue–VoH). Maximum voluntary bite force (MBF) was measured by a digital gnathodynamometer in the posterior and anterior regions. Sex, age, surgical and loading protocols and ridge morphology were tested as independent variables. MP and MBF tests were performed at baseline (pre‐treatment) and the 3‐, 6‐ and 12‐month after implant loading. Descriptive statistics, independent t‐test, and linear mixed‐effect model (LMM) regression were used for data analysis. Results: Seventy‐four participants were assessed and 73 completed the 1‐year follow‐up. Statistically significant improvements in functional parameters were observed in all follow‐up periods compared to baseline (p <.001). The flapless protocol was associated with higher improvement in MP at the 3‐month follow‐up (p =.004), while less resorbed ridges were associated with better MP (p =.038) and higher MBF (p <.001). Conclusion: The mandibular overdenture protocol using four titanium–zirconium mini implants was effective in improving MP and MBF of edentulous patients, compared to pre‐treatment values. The findings also suggest that improvements in chewing function and bite force are impacted by clinical factors since better outcomes were observed for flapless surgeries and less resorbed edentulous ridges. CLINICAL TRIAL REGISTRATION: ClinicalTrials.Gov ID NCT04760457. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this in vitro study was to evaluate the effect of potassium aluminum sulfate (alum) application on the stainability and translucency of computer‐aided design and computer‐aided manufacturing (CAD‐CAM) materials after coffee thermocycling (CTC). Materials and Methods: Disk‐shaped specimens (Ø10 × 1 mm; N = 200) were fabricated by using additively (Crowntec [CT] and Varseo Smile Crown Plus [VS]) and subtractively manufactured (Brilliant Crios [RCR], CEREC Block [FC], and Vita Enamic [VE]) CAD‐CAM materials and polished. All specimens were randomly divided into two groups as alum applied and control (n = 10). All specimens were then subjected to CTC (10,000 cycles at 5–55°C) and color coordinates were measured at each time interval. Color differences (ΔE00) and relative translucency parameters (RTPs) were calculated and the data were statistically analyzed (a = 0.05). Results: Among tested time intervals, alum applied specimens had their lowest ΔE00 after alum application (p ≤ 0.006), except for FC (p = 0.177). In addition, alum applied RCR had lower ΔE00 values than its control specimens (p = 0.029). Alum applied specimens had their lowest RTP after CTC (p < 0.001) and alum application decreased the RTP of CT (p = 0.010). CTC reduced the RTP of all materials in control groups (p < 0.001). Alum applied CT had higher RTP than its control specimens (p = 0.049). Conclusions: Alum application's effect on color change varied depending on the material and alum mostly resulted in clinically acceptable changes in translucency. CTC led to unacceptable color and translucency changes based on previously reported threshold values. Clinical Significance: Optical properties of CAD‐CAM materials and the sustainability of these properties over time is critical for longevity. Alum may improve the color stability of reinforced composite resin when subjected to long‐term coffee consumption. [ABSTRACT FROM AUTHOR]

This study evaluated the influence of silane heat treatment and glass fiber fabrication type, industrially treated (I) or pure (P), on flexural and compressive strength of methacrylate resin bars (BISGMA/TEGDMA, 50/50%). Six groups (n = 10) were created: I-sil: I/silanated; P-sil: P-silanated; I-sil/heat: I/silanated heated to 100°; P-sil/heat: P/silanated heated to 100°; (I: I/not silanated; and P: P/not silanated. Specimens were prepared for flexural strength (10×2×1mm) and for compressive strength 9.5 × 5.5 × 3 mm) and tested at 0.5 mm/min. Statistical analysis demonstrated the following for flexural strength (P < 0.05): I-sil: 155.89 ± 45.27BC; P-sil: 155.89±45.27BC; I-sil/heat: 130.20±22.11C; P-sil/heat: 169.86±50.29AB; I: 131.87±15.86C. For compressive strength, the following are demonstrated: I-sil: 1367.25 ± 188.77ab; P-sil: 867.61 ± 102.76d; I-sil/heat: 1162.98 ± 222.07C; P-sil/heat: 1499.35 ± 339.06a; and I: 1245.78 ± 211.16bc. Due to the impossibility of incorporating the stipulated amount of fiber, P group was excluded. Glass fiber treatment with heated silane enhanced flexural and compressive strength of a reinforced dental methacrylate. [ABSTRACT FROM AUTHOR]

Introdução: O atendimento de idosos exige atenção ao seu estado de saúde físico, psíquico e social, para que assim possa ser feita uma efetiva promoção à sua saúde. Este trabalho relata o tratamento de paciente desdentado total envolvendo odontologia, medicina e psicologia. Paciente do gênero masculino, 63 anos, compareceu ao projeto de extensão overdenture para desdentados totais na geriatria queixando-se de estética insatisfatória, instabilidade de suas próteses, principalmente a inferior e dificuldade de alimentar-se. Na anamnese e nos questionários de satisfação, habilidade (escala EVA) e qualidade de vida (OHIP EDENT e GoHAI), o paciente relatou altos índices de insatisfação com os aparelhos atuais, dificuldade mastigatória, pobre qualidade de vida e reclusão social. O exame clínico identificou um par de próteses mucosuportadas apresentando insuficiente retenção, instabilidade oclusal, sobreextensão das bases e coloração dos dentes que desagradavam o paciente. Foi planejada nova prótese total superior e overdenture inferior sobre implantes. O mesmo foi encaminhado para atendimento médico geriátrico e psicológico. Os exames médicos apontaram alterações sistêmicas que contraindicaram a instalação dos implantes imediatamente, mas nenhuma alteração dos padrões cognitivos e motores foi identificada (teste mini-mental, escala de Lawton e escala de Katz). Assim sendo, foram feitas próteses totais bimaxilares até liberação para procedimento cirúrgico. Os questionários foram reaplicados após a instalação das novas próteses e os resultados mostraram uma melhora vertiginosa dos índices de satisfação e habilidade mastigatória, na qualidade de vida e reinclusão social. O acompanhamento com a psicóloga mostrou disponibilidade e satisfação para e com o tratamento e o paciente relatou se sentir acolhido por toda a equipe médica e odontológica, bem como que esses cuidados melhoraram sua qualidade de vida. Portanto, o trabalho em equipe destinado a essa população é de suma importância para garantir o melhor planejamento e garantir a promoção de saúde na sua integralidade. [ABSTRACT FROM AUTHOR]

Statement of Problem: Printed casts and dental devices and prostheses are increasingly being used, and the ecological impact of additive manufacturing should be considered in addition to the fabrication accuracy and surface properties of the printed object. To overcome the ecological drawbacks of alcohol postprocessing, water-washable, 3-dimensionally (3D) printable cast resins and postprocessing cleaning solutions that do not include alcohol have been introduced. However, whether using only water rather than chemical solvents would enable the surface smoothness and hardness required for accurate diagnostic and prosthetic procedures is unknown., Purpose: The purpose of this in vitro study was to evaluate the effect of resin type (water-washable or nonwater washable) and postprocessing cleaning solution on the surface roughness and microhardness of 3D printed dental cast resins., Material and Methods: One hundred eight disk-shaped specimens (Ø10×2 mm) were additively manufactured (AM) from 3 dental cast resins: 2 water-washable (Epax (WW1) and Phrozen (WW2)) and 1 nonwater-washable resin (KeyModel Ultra resin-beige (NWW)) with a printer (n=36). Specimens in each resin type were divided into 3 groups for the application of postprocessing cleaning solution (water, 98% isopropyl alcohol [IPA] or methyl ether solvent) and polymerized after cleaning. The surface roughness (R a , µm) and Vickers microhardness (HV) were measured. Laser microscope images were made of 1 specimen from each group., Results: NWW-IPA (control group) had a similar R a to WW2-water (P=.81) and WW2-methyl ether solvent (P=.511). NWW-IPA had lower HV than WW2-water (P<.001) and WW1-methyl ether solvent (P=.001). Solutions had no significant effect on the R a of WW1 (P≥.554) and WW2 (P≥.805). WW1 had higher surface irregularities with water, whereas no significant difference was visually observed with IPA or methyl ether solvent. Solutions had a similar effect on the surface of WW2 when evaluated visually with the laser microscope., Conclusions: Resin type and postprocessing cleaning solution affected the surface roughness and microhardness of 3D printed dental cast resins, except for the surface roughness of tested water-washable resins. Water or methyl ether solvent cleaned water-washable resin (WW2) had surface roughness and hardness similar to commonly used nonwater-washable cast resin., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)