RESUMO

O avanço da tecnologia de digitalização de imagens e desenvolvimento de dispositivos de fresagem possibilitaram a otimização de diversos processos na Odontologia. O emprego do escaneamento intraoral e do sistema CAD-CAM (CAD - Computer Aided Design; CAM - Computer Aided Manufacturing) aprimorou a realização de reabilitações protéticas, permitindo a obtenção de peças de alta qualidade em tempo reduzido. O objetivo deste trabalho é relatar um caso de reabilitação de um incisivo central inferior a partir de escaneamento intraoral, com scanner Omnicam (DentsplySirona Charlotte, NC, EUA) e aplicação do sistema CAD-CAM.

The advancement of image digitization technology and the development of milling devices have made it possible to optimize various processes in Dentistry. The use of intraoral scanning and the CAD-CAM system (CAD - Computer Aided Design; CAM - Computer Aided Manufacturing) has improved the performance of prosthetic rehabilitations, allowing the obtaining of high quality parts in a reduced time. The objective of this work is to report a case of rehabilitation of a lower central incisor using intraoral scanning, with an Omnicam scanner (Dentsply Sirona) and application of the CAD-CAM system.

RESUMO

OBJECTIVE: To compare the clinical periodontal parameters of teeth restored with a single ceramic crown, with and without crown lengthening procedure. METHODS: This prospective, longitudinal, controlled, and single-blinded clinical trial involved 22 patients with a total of forty-one teeth with ceramic crowns. The teeth were divided into two groups: test (n = 21), comprising teeth rehabilitated post crown-lengthening surgery, and control (n = 20), comprising teeth rehabilitated without crown-lengthening surgery. Plaque index (PI), gingival index (GI), probing depth (PD), bleeding on probing (BoP), and clinical attachment level (CAL) were compared between groups (surgically treated and non-surgically treated) and within each group for each type of site (treated -tt; adjacent - ad; and nonadjacent - nad). Additionally, gingival phenotype (GP), gingival recession (GR), and keratinized tissue width (KTW) were also assessed post- restoration. Statistical analyses used a significance level set at 5 %. RESULTS: PI, GI, and BoP were reduced, but no statistically significant differences were observed within each group or between groups for most follow-up periods. CAL of the TT sites was consistently higher in the test group, and PD was also higher in the test group (p < 0.05), except at T3. adPD, nadPD, adCAL, and nadCAL demonstrated no significant differences between groups and periods. A significant association was identified between GP and the occurrence of GR, with the thick-flat phenotype demonstrating less association with GR, regardless of whether crown lengthening was performed or not. CONCLUSION: Crown-lengthening surgery in rehabilitated teeth does not significantly affect PI and GI after 12 months. Although crown-lengthening surgery affected PD and CAL in TT sites, it did not affect adjacent and non-adjacent sites. CLINICAL RELEVANCE: These findings emphasize the importance of considering individual patient factors and the potential impact on periodontal tissues when planning crown-lengthening surgery. Clinicians must have a comprehensive understanding of the dynamics of the periodontal tissues involved in restorative treatments to optimize the procedure, increase success rates, and minimize potential complications.

Assuntos

RESUMO

Although advancements in CAD/CAM technology allow for more personalized treatments, it is not clear how modifications in the CAD/CAM milling process could affect the restoration surface conditions and their mechanical behavior. The objective of this study was to evaluate the effect of different CAD/CAM milling protocols on the topography and fracture behavior of zirconia monolithic crowns (3Y-PSZ) subjected to a chewing simulation. Monolithic 3Y-PSZ premolar crowns were milled using three protocols (n = 13) (slow (S), normal (N), and fast (F)). Crowns were cemented on a dentin analog abutment and subjected to mechanical aging (200 N, 2 Hz, 1,500,000 cycles, 37 °C water). Surviving crowns were subjected to compressive load test and analyzed using fractography. Fracture load data were analyzed with two-parameter Weibull analysis. The surface topography of the crowns was examined with a stereomicroscope and a 3D non-contact profiler. All crowns survived the chewing simulation. Crowns milled using the F protocol had the greatest characteristic fracture load, while crowns produced with the S protocol showed high Weibull modulus. Groups N and S had a more uniform surface and detailed occlusal anatomy than group F. The CAD/CAM milling protocol affected the topography and mechanical behavior of 3Y-PSZ monolithic crowns.

RESUMO

Finite element analysis (FEA) has been used to analyze the behavior of dental materials, mainly in implantology. However, FEA is a mechanical analysis and few studies have tried to simulate the biological characteristics of the healing process of loaded implants. This study used the rule of mixtures to simulate the biological healing process of immediate implants in an alveolus socket and bone-implant junction interface through FEA. Three-dimensional geometric models of the structures were obtained, and material properties were derived from the literature. The rule of mixtures was used to simulate the healing periods-immediate and early loading, in which the concentration of each cell type, based on in vivo studies, influenced the final elastic moduli. A 100 N occlusal load was simulated in axial and oblique directions. The models were evaluated for maximum and minimum principal strains, and the bone overload was assessed through Frost's mechanostat. There was a higher strain concentration in the healing regions and cortical bone tissue near the cervical portion. The bone overload was higher in the immediate load condition. The method used in this study may help to simulate the biological healing process and could be useful to relate FEA results to clinical practice.

Assuntos

RESUMO

The aim of this study was to evaluate the mechanical behavior of UCLA and Mini-conical abutments for implants with Tri-channel connections regarding torque loss and vertical misfit. Twenty 3-element metal-ceramic fixed partial dentures (FPD) supported by 2 implants were manufactured and divided into 2 groups (n = 10): UCLA (group 1) and Mini-conical Abutments (group 2). The evaluation of torque loss was carried out before and after mechanical cycling, while the vertical fit was evaluated throughout the different stages of manufacturing the prostheses, as well pre- and postcycling (300,000 cycles, 30 N). Statistical analyses of torque loss and vertical misfit were performed using the linear mixed effects model. Both groups showed torque loss after mechanical cycling (P < .05); however, there was no significant percentage differences between them (P = .795). Before cycling, the groups showed a significant difference in terms of vertical misfit values (P < .05); however, this difference was no long observed after cycling (P = .894). Both groups showed torque loss after the cycling test, with no significant difference (P > .05). There was no significant difference in vertical misfit after mechanical cycling; however, in group 1 (UCLA) there was accommodation of the implant-UCLA abutment interface, while group 2 (Mini-conical abutment) did not show changes in the interface with the implant after the test. Both groups behaved similarly regarding the torque loss of the prosthesis retention screws pre- and postmechanical cycling, with greater loss after the test.

Assuntos

RESUMO

A evolução dos tratamentos em implantodontia possibilitou uma mudança nos tratamentos reabilitadores para pacientes edêntulos, tornando possível a colocação de próteses fixas, que proporcionam maior qualidade de vida para estes pacientes. Para que estas próteses tenham bom desempenho e longevidade satisfatórios é essencial que se mantenha um padrão adequado de higienização bucal e manutenção profissional. Assim, o objetivo deste trabalho foi realizar uma revisão de literatura a respeito dos principais recursos disponíveis para higienização e manutenção das próteses totais fixas sobre implante (protocolo de Branemark), tanto nos cuidados domiciliares dos pacientes quanto no atendimento profissional do cirurgião dentista. Foi realizada uma busca eletrônica, não sistemática, nas bases de dados Lilacs, Pubmed/Medline, Scielo e ScienceDirect, cruzando-se os seguintes descritores: "Higiene Oral"; "Implantes Dentários"; "Implantação Dentária"; "Manutenção"; "Prótese Dentária Fixada por Implante" e "Prótese Dentária". Foram consultados artigos de revisão de literatura, revisão sistemática, meta-análise, estudos clínicos randomizados, além de livros pertinentes ao assunto, publicados no período de 1995 a 2022.Verificou-se na literatura disponível que os principais instrumentos indicados para uso domiciliar são escova dental, fio dental, escova interdental, irrigador oral, dentifrício e enxaguatório. No atendimento profissional em consultório odontológico deve ser dispendida atenção especial às instruções passadas ao paciente e também fazer o possível para motivar e encorajar o seu engajamento na rotina de higienização, além do acompanhamento periodontal, possíveis substituições de parafusos e instalação de placa oclusal estabilizadora, quando necessário. Manter uma higiene oral adequada é essencial para o sucesso das próteses fixas sobre implantes e o cirurgião dentista desempenha um papel crucial não apenas ao realizar o acompanhamento periódico do paciente, mas também ao sugerir os instrumentos mais apropriados, instruir sobre a higiene oral adequada e motivar o paciente a manter a saúde bucal satisfatória(AU)

The evolution of treatments in implantology has enable a change in rehabilitation treatments for edentulous patients, making it possible to place fixed prostheses that provide a better quality of life for these patients. In order to ensure good performance and satisfactory longevity, it is essential to maintain an appropriate standard of oral hygiene and professional maintenance. Thus, the objective of this work was to conduct a literature review on the main resources available for cleaning and maintenance of complete fixed prostheses on implants (Branemark protocol), both in the patients' home care and in the professional care provided by the dentist. A nonsystematic electronic search was carried out in the Lilacs, Pubmed/Medline, Scielo, and ScienceDirect databases, crossing the following descriptors: "Oral Hygiene"; "Dental Implants"; "Dental Implantation"; "Maintenance"; "Dental Prosthesis, ImplantSupported"; and "Prosthodontics". Literature review articles, systematic reviews, meta-analyses, randomized clinical studies, and relevant books on the subject published from 1995 to 2022 were consulted. The literature available indicates that the main instruments recommended for home care are toothbrush, dental floss, interdental brush, oral irrigator, toothpaste, and mouthwash. In the professional dental office, special attention should be given to the instructions given to the patient, as well as to motivate and encourage their engagement in the hygiene routine, in addition to periodontal monitoring, possible screw replacements, and installation of an occlusal splint when necessary. Maintaining adequate oral hygiene is essential for the success of fixed prostheses on implants, and the dentist plays a crucial role, not only in providing periodic patient follow-up, but also in suggesting the most appropriate instruments, instructing on adequate oral hygiene, and motivating the patient to maintain satisfactory oral health(AU)

Assuntos

RESUMO

PURPOSE: The objective of this retrospective study was to evaluate the effect of the interproximal contour of single external hexagon implant restorations on the prevalence of peri-implantitis. MATERIAL AND METHODS: Records of 96 patients and 148 external hexagon (EH) implants with time in function ranging from 1 to 17 years were included in the study. The most recent clinical and radiographic data were collected from records and the prevalence of peri-implantitis was defined according to the 2017 World Workshop on the Classification of Periodontal and Peri-implant Diseases and Conditions. Marginal bone level (MBL), emergence angle (EA), emergence profile (EP), and crown/implant platform horizontal ratio (CIHR) were obtained from periapical radiographs. Dichotomous variables at the patient- and implant level were compared with association tests. Mann-Whitney U-Test was performed to compare continuous quantitative values between the studied groups. Binomial logistic regression was conducted to identify risk indicators associated with the peri-implantitis event at the patient- and implant level, with the significance level set at 5% for all tests. RESULTS: Nineteen patients (19.2%) and 24 implants (16.2%) with a mean time in function of 5.0 ± 4.7 years were classified as having peri-implantitis. No statistically significant differences concerning gender, mean age, implant location in the jaw, or time in function were observed between patients with or without peri-implantitis (p > 0.05). Of 24 implants with peri-implantitis 10 (41.7%) displayed EA ≤ 30° (16.4%) while 14 (58.3%) presented EA > 30° with no statistical difference between the groups (p > 0.05). No statistically significant associations were identified between EA, EP, or CIHR and the prevalence of peri-implantitis. CONCLUSION: The findings seem to indicate that the EA, EP, and CIHR of single restorations over external hexagon implants are not associated with the presence of peri-implantitis. However, prospective studies with larger samples are required to better ascertain such an association in the long term.

Assuntos

RESUMO

OBJECTIVE: This study aimed to explore the cross-sectional and prospective associations between self-reported functionality of complete dentures (FCD), satisfaction with complete dentures (SCD) and the ability to chew hard food (ACHF) on the one hand and the frailty index (FI) on the other hand among edentulous community-dwelling older Japanese people. METHODS: The study examined 770 edentulous participants of the Nihon University Japanese Longitudinal Study of Aging. The self-reported FCD, SCD and ability to chew six groups of food (from hardest to softest) with complete dentures were the independent variables at the baseline. The FI was computed including 40 deficits as the dependent variable at the baseline and 4 years later. Cross-sectional and prospective generalized linear regression models were fitted controlling for age, gender, marital status, education, working status and area of residence. RESULTS: The use of non-functional complete dentures and dissatisfaction with complete dentures were both associated with a higher FI cross-sectionally (3.9% [95% CI 2.2-5.6] and 3.2% [95% CI 1.5-4.9], respectively) and prospectively (3.9% [95% CI 2.0-6.0] and 3.3% [95% CI 1.3-5.3], respectively). Regarding the ability to chew, a higher FI at baseline was observed among those able to chew food of Group 2 (1.9%, [95% CI 0.1-3.7]) and Groups 4-6 (1.9%, [95% CI 0.1-3.7]), and a progressive increment in the FI, as the participants reported being able to chew softer groups of food at the follow-up (Group 2: 2.2% [95% CI 0.05-4.3]; Group 3: 3.6% [95% CI 1.2-6.0]; and Groups 4-6: 3.4 [95% CI 0.7-6.1]). CONCLUSION: Self-reported use of non-functional complete dentures, dissatisfaction with dentures and a reduced ACHF with complete dentures were associated with a higher FI both cross-sectionally and prospectively.

Assuntos

RESUMO

This study aimed to answer the question formulated according to the PICO strategy: 'Which essential oils show antimicrobial activity against biofilms formed on dental acrylic resin?' composed by population (dental acrylic resin), intervention (application of essential oils), comparison (denture cleansers, antifungal drugs, chlorhexidine, and oral mouthwashes), and outcome (antibiofilm activity). In vitro experimental studies evaluating the activity of EOs on biofilm formed on acrylic resin were included. PRISMA guidelines were followed, and the search was performed in the PubMed, Science Direct, Embase, and Lilacs databases and in the gray literature using Google Scholar and ProQuest in December 2023. A manual search of the reference lists of the included primary studies was performed. Of the 1467 articles identified, 37 were selected for full-text reading and 12 were included. Twelve EOs were evaluated, of which 11 showed activity against Candida spp., 3 against Staphylococcus aureus, and 1 against Pseudomonas aeruginosa. The EOs of Cymbopogon citratus, Cinnamomum zeylanicum, and Cymbopogon nardus showed higher action than chlorhexidine, C. nardus higher than Listerine, C. citratus higher than nystatin, and Melaleuca alternifolia higher than fluconazole and nystatin. However, chlorhexidine was more effective than Lippia sidoides and Salvia officinalis, sodium hypochlorite was more effective than L. sidoides, nystatin was more effective than Zingiber officinale, Amphotericin B more effective than Eucalyptus globulus and M. alternifolia. In conclusion, the EOs of C. zeylanicum, C. citratus, C. nardus, and M. alternifolia showed antimicrobial activity to reduce biofilm on dental acrylic resin.

Assuntos

RESUMO

PURPOSE: This study aimed to develop and evaluate a simple, non-destructive method for assessing the misfit and passivity of implant-retained prostheses frameworks. MATERIALS AND METHODS: To simulate the rehabilitation of a mandible posterior partially edentulous area using 3-unit screw-retained frameworks supported by two implants were fabricated and divided into the following five groups (n = 10 in each group): OP = one-piece framework cast in Co-Cr with the conventional method (control-group); Co-Cr frameworks sectioned and welded by laser (=LAS) or tungsten inert gas (=TIG); Co-Cr CAD-CAM = milled Co-Cr framework; Zir CAD-CAM = milled zirconia framework. The horizontal |X| and vertical |Y| misfits were measured using confocal laser scanning microscopy with one or both screws tightened. Data were analyzed by a two-way ANOVA with repeated measures and Bonferroni correction (α = 0.05). RESULTS: The greatest |X| misfit was observed in the OP group with both screws tightened (290 µm) and one screw tightened (388 and 340 µm). The conventional casting groups sectioned and welded by laser or TIG had lower mean values (235.35 µm, both screws tightened; and 275 µm, one screw tightened) than the OP framework. However, these values still exceeded those of the milled Co-Cr and zirconia frameworks (190 and 216 µm with both screws tightened). Across all reading conditions, every framework subjected to testing consistently maintained vertical |Y| misfit levels below the threshold of 53 µm; however, the milled frameworks exhibited higher vertical misfits than the frameworks obtained by the conventional cast method. CONCLUSIONS: The frameworks, whether cast and sectioned with laser welding or milled from Co-Cr, exhibit improved marginal misfit and enhanced passive fit when compared to other fabrication methods. Additionally, the use of confocal laser scanning microscopy is highly effective for passivity and misfit analysis.