Peri-implant Outcomes from Customized Healing Abutments Using Immediate Implants: A Systematic Review.

PURPOSE: To evaluate the peri-implant outcomes of customized healing abutments (CstHA) placed on dental implants inserted in fresh tooth extraction sockets. MATERIALS AND METHODS: The study was registered on PROSPERO: CRD42022304320. A systematic search in PubMed, Scopus, and Web of Science was conducted between April 2022 and October 2022 to identify clinical studies involving immediate implant surgery associated with CstHA placement. The Joanna Briggs Institute Critical Appraisal and RoB2 tool were performed for the risk of bias analysis. RESULTS: A total of 12 studies were included, most of them with low risk of bias. Four studies compared CstHA vs conventional healing abutments (CnvtHA), two compared CstHA vs cover screw and collagen matrix (CMa), and six were clinical case series. For the CstHA vs CnvtHA comparison, favorable results were observed for CstHA considering papilla maintenance and probing depth, yet the mean marginal bone level was statistically similar between CstHA and CnvtHA. CstHA showed advantages when compared to CMa for total bone volume, papilla height, and midfacial mucosa maintenance. Significantly less horizonal bone loss was reported when using CstHA compared with CMa. Horizontal and vertical bone loss was observed in a few (or no) sites in the case series using CstHA. CONCLUSIONS: CstHA provides favorable peri-implant response because in general it does not result in a significant loss of soft and hard tissues.

The influence of printing angle on color and translucency of 3D printed resins for dental restorations.

OBJECTIVES: To evaluate the influence of printing orientation on color and translucency of 3D printing restorative resins. METHODS: Four 3D printing resin systems in the available shades (DFT-Detax Freeprint Temp- A1, A2,A3; FP-Formlabs Permanent Crown- A2,A3,B1,C2; FT- Formlabs Temporary CB- A2,A3,B1,C2; GCT-GC Temporary- Light, Medium) were evaluated. Three samples (10×10×1.2 mm) from each material were printed at two different printing orientations (0° and 90°) and polished to 1.00 ± 0,01 mm of thickness. Spectral reflectance was measured against black background using a calibrated spectroradiometer, CIE D65 standard illuminant and the 45°/0°geometry. Color and translucency differences were evaluated using CIEDE2000 metric (ΔE00) and 50:50% perceptibility (PT00 and TPT00) and acceptability (AT00 and TAT00) thresholds. RESULTS: In general, color changes due to printing orientation at (0° and 90°) were mainly produced by ΔL* or ΔC* . ΔE00 were above PT00 for all DFT shades, FP-B1, FP-C2, FT-A2 and FT-B1. Only for DFT-1, ΔE00 was above AT00. ΔRTP00 values were above TPT00 for DFT-A1, DFT-A3, FP-B1 and FT-B1, but lower than TAT00. The direction of the changes in translucency (ΔRTP00) depends on the material and shade. SIGNIFICANCE: The selection of building orientation (0° and 90°) for the 3D printed resins influence the visual color and translucency and therefore their esthetic appearance. These aspects should be considered when printing dental restorations using the evaluated materials.

A systematic review and meta-analysis on using preheated resin composites as luting agents for indirect restorations.

OBJECTIVES: This systematic review investigated the hypothesis that preheated resin composites (RCs) used as luting agents improve the mechanical properties, physicochemical performance, and color of indirect ceramic restorations. MATERIALS AND METHODS: Literature search was performed in three databases (Medline/PubMed, Scopus, and Web of Science) and in the grey literature (OpenGrey, ProQuest, and Catalog of Theses & Dissertations from CAPES). Eligibility criteria included only studies comparing at least one preheated RC used as a luting agent with resin cements. RESULTS: Data regarding the mechanical properties, physicochemical characteristics, and color were analyzed qualitatively, and the microtensile bond strength and film thickness were also evaluated by meta-analysis. The search strategy identified 3894 papers, and 28 were full-text screened. Seven studies were included in the review, and 5 were included in the meta-analysis. No significant difference was found for microtensile bond strength (P = 0.14). Preheated RCs showed significantly higher film thickness than resin cements (P = 0.001). CONCLUSION: Overall, the use of preheated RCs as luting agents offers similar to poorer performance than using resin cements for bonding indirect restorations. CLINICAL RELEVANCE: Despite the claim that preheated RC could be used as a luting agent, further studies should investigate the effect of clinically unacceptable film thickness.

Fracture Load and Failure Mode of CAD-on Ceramic Structures.

This study evaluated the fracture load (Lf) and the failure mode of CAD-on (Ivoclar Vivadent) ceramic structures, testing the hypotheses that Lf of multilayer structures is governed by the veneering ceramic strength and that chipping is more frequent in multilayer than monolithic structures. Disc-shaped specimens were fabricated as follows: CAD-on- trilayer structure composed of Y-TZP (yttria stabilized tetragonal zirconia polycrystal- IPS e.max ZirCAD) infrastructure, fusion glass-ceramic (IPS e.max CAD Crystall/Connect) and lithium disilicate-based glass-ceramic (IPS e.max CAD); YLD- bilayer structure composed of Y-TZP infrastructure and fluorapatite layering ceramic (IPS e.max Ceram); LDC- monolithic lithium-disilicate glass-ceramic (IPS e.max CAD); and YZW- monolithic Y-TZP (Zenostar Zr Translucent). The specimens were loaded in compression until failure and fracture surfaces were evaluated using fractographic principles. Lf values were statistically analyzed using the Weibull statistics, Kruskal-Wallis and Dunn tests (a= 0.05). YZW (1329 N) and CAD-on (1085 N) showed the greatest Lf median values, followed by YLD (832 N) and LDC (421 N). All monolithic structures (LDC and YZW) fractured catastrophically and all YLD structures failed by chipping. The CAD-on technique seems to be a very promising fabrication process because it showed high Lf, similar to monolithic zirconia, and small chipping rate.

Whiteness difference thresholds in dentistry.

OBJECTIVE: To determine the visual whiteness thresholds for esthetic dentistry using the whiteness index for dentistry based on CIELAB color space (WID). METHODS: A total of 60 observers (Dentists and Laypersons; n=30) from three research sites participated in the study. A psychophysical experiment based on visual assessments of simulated images of teeth on a calibrated display was performed. Images of simulated upper central incisors (SUCI) were consecutively displayed in pairs (60) and the whiteness of each SUCI pair was compared. WID was used to calculate the visual thresholds (WPT- perceptibility threshold; and WAT- acceptability threshold) with 95% confidence intervals (CI) and a Takagi-Sugeno-Kang (TSK) Fuzzy Approximation model was used as fitting procedure. Data was statistical analyzed using paired t-test (α=0.05). RESULTS: WPT and WAT were 0.72 (CI: 0.0-2.69; r2=0.52) and 2.62 (CI: 0.2-7+; r2=0.57) WID units, respectively. Significant differences (p<0.05) were found between WPT and WAT, and between dentist (WPT=0.46WID units; WAT=2.20 WID units) and layperson (WPT=0.94 WID units; WAT=2.95 WID units). SIGNIFICANCE: The visual whiteness difference thresholds determined with WID index can serve as reference values for research and manufacturing of dental materials, and for clinical practice situations such as assessing the effectiveness of bleaching treatments.

Influência dos agentes clareadores na dureza e cor de materiais restauradores diretos

Avaliar, in vitro, a variação de cor e dureza de três materiais restauradores (3M ESPE): Ketac Molar Easymix (KME); Vitremer (VT) e resina composta Filtek Z250 (Z250) após o clareamento com peróxido de carbamida a 37% (PC37- Whiteness Super) e peróxido de hidrogênio a 35% (PH35- Whiteness HP Maxx). Materiais e método: foram confeccionados 108 corpos de prova (CP), sendo 36 para cada material, avaliados inicialmente (baseline) e após cada aplicação dos agentes clareadores realizadas em subseqüentes 7 períodos, ou seja, após 1, 7, 14, 21, 28, 35 e 42 dias. As avaliações colorimétricas (coordenadas CIELAB) dos CP foram realizadas usando um espectrofotômetro (Easyshade, Vita Zahnfabrik, Bad Sackingen, Alemanha) sob fundo branco e em ambiente clínico. Para a avaliação da dureza (H), usou-se um durômetro (Pantec HVS 10, Panambra Ind. e Téc. SA, São Paulo, SP Brasil) com penetrador tipo Vickers. Os resultados das diferenças de cor (∆E*ab), diferenças de L* (∆L*) e H foram calculados e avaliados estatisticamente usando análise de variância (ANOVA) e as diferenças avaliadas pelo teste Tukey (α=0,05). Resultados: após o clareamento, houve alterações significativas no valor de ∆E*ab para os dois materiais a base de ionômero de vidro (KME e VT), com ambos os clareadores (PC37 e PH35) mostrando efeito similar para cada material. Não houve diferença na H dos materiais. Conclusão: após 42 dias, agentes clareadores alteraram a cor dos materiais ionoméricos e não alteraram a dureza dos materiais testados.

Effect of different irrigating solutions and photo-activated therapy for in vivo root canal treatment.

This study aimed to evaluate histologically the effect of irrigation with 400 ppm Sterilox, 2% and 5% sodium hypochlorite (NaOCl), with and without photo-activated therapy (PAD), in a single-visit root canal treatment of dog's teeth with apical periodontitis (AP). Ten dogs were randomly divided into two groups (n=5): with and without PAD, and the root canals into four subgroups, according to the irrigating solution: SX (400 ppm Sterilox), SH2 (2% NaOCl), SH5 (5% NaOCl) and SS (saline solution) as positive control. A total of 134 root canals were opened and left exposed to the oral environment for 14 days and then sealed for 60 days for AP induction. Then, root canals were treated according to each proposed disinfecting protocol and filled in the same session. After 120 days, the dogs were euthanized and the periapical inflammatory events were evaluated under light microscopy. Qualitative data were submitted to Kruskal-Wallis and Mann-Whitney tests (α=0.05). PAD did not produce significant differences in the scores for apical inflammation when used after chemo-mechanical preparation (p>0.05). The irrigating solutions SX, SH2 and SH5 without PAD were statistically different from SS (p<0.05) that presented the greatest scores for apical inflammation. PAD did not show any additional effect for the treatment of root canals with pulp necrosis and AP in a single visit and 400 ppm Sterilox may be considered an alternative to NaOCl in root canal treatment.

Effect of Different Irrigating Solutions and Photo-Activated Therapy for In Vivo Root Canal Treatment

This study aimed to evaluate histologically the effect of irrigation with 400 ppm Sterilox, 2% and 5% sodium hypochlorite (NaOCl), with and without photo-activated therapy (PAD), in a single-visit root canal treatment of dog's teeth with apical periodontitis (AP). Ten dogs were randomly divided into two groups (n=5): with and without PAD, and the root canals into four subgroups, according to the irrigating solution: SX (400 ppm Sterilox), SH2 (2% NaOCl), SH5 (5% NaOCl) and SS (saline solution) as positive control. A total of 134 root canals were opened and left exposed to the oral environment for 14 days and then sealed for 60 days for AP induction. Then, root canals were treated according to each proposed disinfecting protocol and filled in the same session. After 120 days, the dogs were euthanized and the periapical inflammatory events were evaluated under light microscopy. Qualitative data were submitted to Kruskal-Wallis and Mann-Whitney tests (α=0.05). PAD did not produce significant differences in the scores for apical inflammation when used after chemo-mechanical preparation (p>0.05). The irrigating solutions SX, SH2 and SH5 without PAD were statistically different from SS (p<0.05) that presented the greatest scores for apical inflammation. PAD did not show any additional effect for the treatment of root canals with pulp necrosis and AP in a single visit and 400 ppm Sterilox may be considered an alternative to NaOCl in root canal treatment.

Este estudo realizou uma avaliação histológica do efeito das soluções irrigadoras Sterilox 400 ppm e hipoclorito de sódio (NaOCl) a 2% e 5%, com e sem a terapia fotodinâmica (PAD), na endodontia em sessão única de dentes de cães associados a lesões periapicais (APs). Dez cães foram divididos de forma randomizada em dois grupos (n=5): com e sem PAD, e os canais radiculares em quatro subgrupos, de acordo com a solução irrigadora utilizada: SX (Sterilox 400 ppm), SH2 (NaOCl 2%), SH5 (NaOCl 5%) e SS (solução salina) como controle positivo. Cento e trinta e quatro canais foram abertos e deixados expostos ao meio oral por 14 dias e depois selados por 60 dias para a indução de APs. Na sequência, os canais foram tratados de acordo com cada protocolo de desinfecção proposto e obturados na mesma sessão. Após 120 dias, os cães foram mortos e os eventos inflamatórios periapicais foram avaliados em microscopia óptica. Os dados qualitativos foram analisados estatisticamente pelos testes Kruskal-Wallis e Mann-Whitney (α=0,05). A PAD, quando empregada após o preparo químico-mecânico, não promoveu diferenças significativas nos escores para inflamação apical (p>0,05). As soluções irrigadoras SX, SH2 e SH5 sem PAD apresentaram diferenças estatísticas do grupo SS (p<0,05) que apresentou os maiores escores para inflamação apical. A PAD não apresentou efeito adicional na endodontia em sessão única dos canais com necrose pulpar associados a lesão apical e a solução irrigadora Sterilox 400 ppm pode ser considerada uma alternativa ao NaOCl na terapia endodôntica.

Zirconia as a Dental Biomaterial.

Ceramics are very important in the science of dental biomaterials. Among all dental ceramics, zirconia is in evidence as a dental biomaterial and it is the material of choice in contemporary restorative dentistry. Zirconia has been applied as structural material for dental bridges, crowns, inserts, and implants, mostly because of its biocompatibility, high fracture toughness, and radiopacity. However, the clinical success of restorative dentistry has to consider the adhesion to different substrates, which has offered a great challenge to dental zirconia research and development. This study characterizes zirconia as a dental biomaterial, presenting the current consensus and challenges to its dental applications.

Changes in oral health related quality of life after dental bleaching in a double-blind randomized clinical trial.

OBJECTIVES: This study aimed to assess changes in oral health-related quality of life (OHRQoL) in individuals enroled in a double-blind randomized clinical trial conducted to evaluate the efficacy and safety of two carbamide peroxide concentrations used in at-home vital bleaching in the city of Pelotas, Southern Brazil. METHODS: Ninety-two volunteers with a shade mean of C1 or darker for the six maxillary anterior teeth were randomized into two balanced groups (n=46) according to bleaching agent concentration: 10% or 16% carbamide peroxide. The patients were instructed to use the whitening agent in a tray for 2h once a day for three weeks. To assess changes in OHRQoL, participants completed the oral impact on daily performance (OIDP) at the start and one week after the completion of treatment. Because there was no difference with regard to whitening effect or tooth sensitivity during or after treatment the two groups were merged for the analyses of the current article. Before-and-after changes in OIDP scores were assessed by chi-square and McNemar tests (p<0.05). RESULTS: Mean pre- and post-treatment OIDP scores varied from 0.42 to 0.60. When the frequency of impacts for different activities were compared, there was an increase in difficulty in cleaning teeth (p=0.02) and a significant reduction in smiling and showing teeth with embarrassment (p=0.03). Regarding the symptoms and main oral conditions that generated impact, there was higher number of participants reporting pain (p=0.05) after treatment. In opposite, significant decrease was observed in individuals reporting being unhappy with their appearance (p=0.03). On the contrary, it was showed a decrease in impacts resulting from dental colour was observed after bleaching (p=0.03). CONCLUSION: Quality of life is complex and encompasses different domains. Although positive impact of the dental bleaching was detected, with patients showing more their teeth without embarrassment, difficult in dental hygiene and pain resulting from the treatment were also reported, and this can negatively impact daily performances. Dentists must consider these aspects when performing aesthetics procedures.

Evidências cientificas para a adesão de bráquetes cerâmicos a diferentes substratos odontológicos / Scientific evidences for bonding of ceramic brackets to different dental substrates

Existe uma grande demanda por tratamento ortodôntico em pacientes adultos, que requerem frequentemente uma adequada adesão de bráquetes a vários substratos, além do esmalte dental, tais como: porcelanas, ligas metálicas, amálgama, ouro, dentina, resinas compostas e acrílicas. Objetivo: Apresentar revisão da literatura sobre os mecanismos adesivos empregados para a adesão de bráquetes cerâmicos aos diversos substratos encontrados na clínica odontológica e as propriedades dos bráquetes cerâmicos, sugerindo protocolos adesivos com base em evidências. Métodos: A pesquisa foi realizada na base de dados PubMed, em artigos publicados a partir de 1986, incluindo aos temas: bráquetes cerâmicos e resistência de união em ortodontia. Resultados: A estética e a biocompatibilidade foram reportadas como as maiores vantagens dos bráquetes cerâmicos. As principais limitações foram a necessidade de utilização de um agente de união (ex. silano) para a adesão química aos adesivos resinosos, a elevada resistência friccional oferecida aos arcos metálicos (prejudicando a mecânica de deslizamento) e o desgaste dentário em caso de contato entre bráquete e dente (antagonista). Conclusão: A adesão (resistência de união, em MPa) dos bráquetes deve ser sufi-cientemente elevada para resistir à descolagem espontânea, suportar os esforços mastigatórios e cargas parafuncionais eventuais, além de absorver os estresses exercidos pelo arco ortodôntico no controle tridimensional do dente. Ao mesmo tempo, deve ser suficientemente baixa para evitar a transmissão de estresse elevado ao substrato, na remoção do bráquete ao final do tratamento...

There is a high demand for orthodontic treatment in adult patients, who often require a proper adhesion of brackets to various substrates in addition to enamel, such as: porcelain, metal alloys, amalgam, gold, dentin, composite resins and acrylic. Objective: To present a comprehensive literature review on the bonding mechanisms used to bond ceramic brackets to various substrates found in the dental clinic and the properties of ceramic brackets, suggesting bonding protocols grounded on Evidence-based dentistry. Methods: The search was done in the PubMed database considering published papers from 1986 on ceramic brackets and bond strength in orthodontics. Results: Biocompatibility and esthetics were reported as the major advantages of ceramic brackets. The main limitations were the need to use a bonding agent (e.g. silane) for chemical bond to the resin-based adhesives, the high frictional resistance offered by the metal arches (impairing the sliding mechanics) and the opposing tooth wear in case of contact between bracket and tooth. Conclusion: Brackets adhesion (bond strength, in MPa) should be high enough to resist spontaneous debonding, to withstand the masticatory forces and any parafunctional loads, in addition to absorbing the stresses generated by the orthodontic arch in the three-dimensional control of the tooth. At the same time, it should be low enough to avoid the transmission of high stresses to the substrate on debonding the bracket at the end of treatment...

Uso de enxerto homógeno para reconstrução de defeitos ósseos de maxilares atróficos / Use of homogenous graft for bone reconstruction of defects of atrophic maxilla

A evolução da Implantodontia nas últimas duas décadas trouxe consigo a necessidade de aprimorar a utilização de técnicas de aumento dos rebordos ósseos maxilares, receptores dos implantes dentários, por meio de enxertos ósseos. Com este objetivo, a utilização de material proveniente de bancos de ossos, passou a despertar bastante interesse aos cirurgiões dentistas, por apresentar vantagens como redução do tempo cirúrgico e menor morbidade. Este trabalho relata um caso clínico de paciente portador de severa atrofia de maxila, com necessidade de reconstrução total do rebordo alveolar usando enxertia óssea, seguida de reabilitação com implantes. Os resultados reportados na literatura e apresentado neste relato de caso demonstram que o osso alógeno é uma alternativa adequada para realização de enxerto ósseo.

The evolution of dental implants over the past two decades has brought along the need to improve the use of augmentation techniques for maxillary bones, recipients of dental implants, using bone grafts. With this aim, the use of material from bone banks has gained the attention of dentists due to advantages such as reduced surgical time and morbidity. This paper reports a clinical case of severe maxilla atrophy, needing complete reconstruction of the alveolar bone using bone grafting, followed by implant rehabilitation. Previous reports and the present clinical case show that bone grafting is an adequate treatment option.

Evaluation of the adaptation of zirconia-based fixed partial dentures using micro-CT technology.

The objective of the study was to measure the marginal and internal fit of zirconia-based all-ceramic three-unit fixed partial dentures (FPDs) (Y-TZP - LAVA, 3M-ESPE), using a novel methodology based on micro-computed tomography (micro-CT) technology. Stainless steel models of prepared abutments were fabricated to design FPDs. Ten frameworks were produced with 9 mm2 connector cross-sections using a LAVATM CAD-CAM system. All FPDs were veneered with a compatible porcelain. Each FPD was seated on the original model and scanned using micro-CT. Files were processed using NRecon and CTAn software. Adobe Photoshop and Image J software were used to analyze the cross-sectional images. Five measuring points were selected, as follows: MG - marginal gap; CA - chamfer area; AW - axial wall; AOT - axio-occlusal transition area; OA - occlusal area. Results were statistically analyzed by Kruskall-Wallis and Tukey's post hoc test (α= 0.05). There were significant differences for the gap width between the measurement points evaluated. MG showed the smallest median gap width (42 µm). OA had the highest median gap dimension (125 µm), followed by the AOT point (105 µm). CA and AW gap width values were statistically similar, 66 and 65 µm respectively. Thus, it was possible to conclude that different levels of adaptation were observed within the FPD, at the different measuring points. In addition, the micro-CT technology seems to be a reliable tool to evaluate the fit of dental restorations.

Influence of Different Mechanisms of Fluoride Release from Adhesive Systems

The objective of this study was to evaluate in vitro the time-dependent fluoride (F) release from three adhesive systems: Clearfil Protect Bond (CPB - Kuraray), FL Bond II (FLB- Shofu) and Adper Single Bond 2 (SB2 - 3M ESPE) (negative control). CPB and FLB are fluoride containing adhesives that use different F releasing mechanisms. The tested hypothesis was that the F releasing mechanism influences the amount of released F in water. Disc-shaped specimens (5 mm × 3 mm) were fabricated using a plastic matrix (Demetron Research Corp). Three specimens were produced for each material and each period of evaluation (1, 7, 14, 21 and 28 days) (n=3). Subsequently, the specimens were stored in 10 mL distilled water at 37° C until the analyses were done using a liquid membrane for selective F ion electrode (Orion 710). Four readings were performed on the first day and the remaining evaluation times had one reading/day. Results were statistically analyzed by two-way ANOVA and Tukey's test (α=0.05). CPB released the greatest amount of fluoride in all evaluated periods with the greatest value at 6th h (0.183 ppm) thereafter decreasing gradually up to the 7th day when it significantly increased again until the 21st day. In most measurements, FLB showed similar mean fluoride release values as SB2. Therefore, the fluoride release mechanism influenced the amount of fluoride released in water, confirming the study hypothesis.

O objetivo deste estudo foi avaliar, in vitro, a liberação de flúor (F), ao longo do tempo, de três sistemas adesivos: Clearfil Protect Bond (CPB-Kuraray), FL Bond II (FLB-Shofu), Adper Single Bond 2 (SB2-3M ESPE) (controle negativo). Os sistemas adesivos CPB e FLB contêm flúor em sua composição e liberam F por diferentes mecanismos. A hipótese testada foi a de que o mecanismo de liberação de F influencia a quantidade de F liberado em água. Foram confeccionados espécimes em forma de discos (5 mm × 3 mm) utilizando uma matriz de plástico (Demetron Research Corp). Foram produzidas 3 amostras para cada um dos materiais, para cada período de avaliação (n=3) (1, 7, 14, 21 e 28 dias). Subsequentemente, as amostras foram armazenadas em 10 mL de água destilada a 37 °C até o momento das leituras que foram feitas usando uma membrana líquida para eletrodo seletivo de íons F (Orion 710). Foram realizadas quatro leituras no primeiro dia; após foi feita uma leitura/dia. Os resultados foram analisados estatisticamente por ANOVA e teste de Tukey (α=0,05). O sistema adesivo CPB liberou a maior quantidade de flúor em todos os períodos avaliados, com o maior valor em 6 H (0,183 ppm), então ela diminuiu gradualmente até o sétimo dia, quando aumentou significativamente até o dia 21. Na maioria das análises realizadas, FLB mostrou valores de liberação de flúor semelhantes aos de SB2. Portanto, o mecanismo de liberação de flúor influenciou a quantidade de fluoreto de liberado em água, confirmando a hipótese do estudo.

Evaluation of the adaptation of zirconia-based fixed partial dentures using micro-CT technology

The objective of the study was to measure the marginal and internal fit of zirconia-based all-ceramic three-unit fixed partial dentures (FPDs) (Y-TZP - LAVA, 3M-ESPE), using a novel methodology based on micro-computed tomography (micro-CT) technology. Stainless steel models of prepared abutments were fabricated to design FPDs. Ten frameworks were produced with 9 mm2 connector cross-sections using a LAVATM CAD-CAM system. All FPDs were veneered with a compatible porcelain. Each FPD was seated on the original model and scanned using micro-CT. Files were processed using NRecon and CTAn software. Adobe Photoshop and Image J software were used to analyze the cross-sectional images. Five measuring points were selected, as follows: MG - marginal gap; CA - chamfer area; AW - axial wall; AOT - axio-occlusal transition area; OA - occlusal area. Results were statistically analyzed by Kruskall-Wallis and Tukey's post hoc test (α= 0.05). There were significant differences for the gap width between the measurement points evaluated. MG showed the smallest median gap width (42 µm). OA had the highest median gap dimension (125 µm), followed by the AOT point (105 µm). CA and AW gap width values were statistically similar, 66 and 65 µm respectively. Thus, it was possible to conclude that different levels of adaptation were observed within the FPD, at the different measuring points. In addition, the micro-CT technology seems to be a reliable tool to evaluate the fit of dental restorations.

Effect of Finish Line on Marginal Fit of Sintered Gold Copings

The aim of this study was to evaluate the vertical marginal gap of sintered gold copings and metal-ceramic crowns with different finish line preparations: a beveled round shoulder (BRS) and a beveled long chamfer (BLC), testing the null hypotheses that there are no differences in marginal gap regardless of finish line and phase of restoration (coping or crown). Stainless steel master models were fabricated to simulate tooth preparation for metal-ceramic crowns with different finish lines (BRS and BLC). Ten dies were obtained from each model. Preparations were coated with 2 layers of spacer to 1 mm from the margin. Sintercast gold copings were prepared, sintered and adjusted to the dies. The copings (n=10) were placed onto the master model and the marginal gap was measured in 24 equidistant points using optical microscopy (X230). An opaque and two body ceramic layers were subsequently applied to the copings and the same measuring procedure was performed for the crowns. The data were analyzed statistically using paired and unpaired Student's t-test (α=0.05). Mean marginal gap values (µm) for the copings and crowns were, respectively: 113.6 and 117.1 for the BRS; and 58.2 and 74.3 for the BLC preparation. Significantly greater marginal gaps (p=0.0307) were found for restorations with BRS than with BLC finish line, which also showed statistically significant differences in the gap size between coping and crown (p=0.001). In conclusion, marginal gap is influenced by ceramic application on copings fabricated on BLC preparation, and greater marginal gaps were found for restorations with BRS finish line, rejecting the experimental null hypotheses.

O objetivo deste estudo foi avaliar a fenda marginal vertical de copings de ouro sinterizado e coroas metalo-cerâmicas com diferentes tipos de término de preparo: ombro arredondado biselado (OAB) e chanfro longo biselado (CLB), testando a hipótese nula de que não há diferenças na adaptação marginal quando se compara o tipo de término ou a fase da restauração (coping ou coroa). Modelos de aço inoxidável foram confeccionados simulando preparos dentais com diferentes términos (OAB e CLB). Dez modelos de gesso foram confeccionados a partir de cada preparo. Duas camadas de espaçador foram passadas em cada preparo, a 1 mm da margem. Os copings de Sintercast confeccionados, sinterizados e ajustados ao modelo de gesso. Os copings (n=10) foram colocados no modelo de aço e a fenda marginal foi medida em 24 pontos equidistantes por meio de microscópio óptico (×230). Uma camada de opaco e duas de porcelana feldspática foram aplicadas sobre os copings e o mesmo processo de mensuração de fenda foi utilizado para as coroas. Os dados foram analisados estatisticamente usando o teste t Student pareado e não-pareado (α=0,05). Os valores médios de fenda marginal (µm) para os copings e coroas foram, respectivamente: 113,6 e 117,1 para OAB; e 58,2 e 74,3 para CLB. Fendas marginais significantemente maiores (p=0,0307) foram observadas nas restaurações com términos OAB quando comparados ao término CLB, o qual mostrou diferenças estatísticas na comparação entre coping e coroa (p=0,001). Em conclusão, a fenda marginal é influenciada pela aplicação de cerâmica em copings fabricados com términos CLB, e fendas marginais maiores foram observadas para restaurações com término OAB, rejeitando-se as hipóteses nulas.

Effect of endodontic sealers on tooth color.

OBJECTIVES: One of the goals of endodontic treatment is the adequate filling of the root canal,which is often done using gutta-percha and sealer. It has been reported that sealer remnants in the coronary pulp chamber cause tooth color changes. Therefore, this study was designed to examine the effect of endodontic sealer remnants on tooth color, testing the hypothesis that sealers cause coronal color changes. METHODS: Forty single-rooted human teeth were endodontically treated leaving excess sealer material in the coronary pulp chamber. The specimens were divided into four groups (n = 10) according to the endodontic sealer used (AH, AH Plus; EF, Endofill; EN,endome´ thasoneN; and S26, Sealer 26). Teeth were stored at 37 8C moist environment.Color coordinates (L*a*b*) were measured with a spectrophotometer before endodontic treatment(baseline-control), 24 h and 6 months after treatment. L*a*b* values were used to calculate color changes (DE). Data were statistically analyzed using Kruskal­Wallis and Mann­Whitney-U tests. RESULTS: Color changes were observed for all groups with S26 and EN producing the greatest mean DE values after 6 months. CONCLUSION: Endodontic sealer remnants affect tooth color confirming the experimental hypothesis. CLINICAL SIGNIFICANCE: This study examined the effect of endodontic sealer remnants on tooth color, and observed that after 6 months, the sealers produced unacceptable color changes.

Migração de implante para o interior do seio maxilar removido pela técnica de Caldwell Luc / Implant migration into maxillary sinus removed using the Caldwell Luc technique

A sinusite maxilar de origem odontogênica pode ser causada pelo deslocamento de corpos estranhos ao seu interior. A proposta deste trabalho é relatar caso de paciente com histórico de deslocamento de implante ao interior da cavidade sinusal ocorrido há três anos e que estava assintomático em relação à sinusite maxilar. O acesso cirúrgico pela técnica de Caldwell-Luc promove um campo adequado para a remoção de corpos estranhos no interior do seio maxilar, sendo muito utilizada na cirurgia bucomaxilofacial

The maxillary sinusitis of odontogenic origin may be caused by displacement of external bodies into the sinus. The purpose of this study is to report the case of a patient with a history of implant displacement into the sinus that occurred three years ago and was asymptomatic with respect to maxillary sinusitis. The Caldwell-Luc technique promoted adequate surgical access to remove the implant from the maxillary sinus. This technique is commonly used in oral and maxillofacial surgery