Exploiting optical coherence tomography to evaluate wear in spiral dental polishing systems.

This study aimed to evaluate the behavior of spiral polishing systems in restorative materials through optical coherence tomography (OCT). Performance of spiral polishers specific to resin and ceramics were evaluated. The surface roughness of restorative materials was measured, and images of the polishers were acquired by OCT and stereomicroscope. Surface roughness was reduced in ceramic and glass-ceramic composite polished with a system specific to resin (p<0.01). Surface area variation was observed on all polishers, except for the medium-grit polisher tested in ceramic (p<0.05). Similarity between images obtained through OCT and stereomicroscopy presented a Kappa inter- and intra-observer of 0.94 and 0.96, respectively. Then, OCT was able to evaluate wear areas in spiral polishers.

Evaluation of ceramic veneer adaptation by optical coherence tomography: a clinical report / Avaliação da adaptação de laminado cerâmico por tomografia de coerência óptica: relato de caso

Introduction: Ceramic veneers represent a treatment approach in aesthetic dentistry. They are indicated in cases of alterations in size, contour, form and color of the teeth. The clinical and radiographic examinations may not allow the correct identification of failures in the treatment with ceramic veneers. Objective: To report the use of Optical Coherence Tomography (OCT) for the evaluation and repair of an aesthetic oral rehabilitation involving ceramic veneers. Case report: A 24-year-old female patient complained of unsatisfied color change in the ceramic veneer placed on the right maxillary central incisor. The clinical examination showed color changes between the middle and incisal thirds of mesial surface of the tooth crown. The OCT sagittal images evidenced the presence of bubbles or gaps in the adhesive interface. The treatment consisted of repair of the restoration by infiltration of a composite resin. Conclusion: The OCT was found to be valid tool to evaluate the adaptation of the ceramic veneer placed on the maxillary central incisor (AU)

Introdução: Laminados cerâmicos representam uma abordagem de tratamento em Odontologia. São indicados em casos de alterações no tamanho, contorno, forma e cor dos dentes. O exame clínico e o emprego de radiografias convencionais podem não permitir a correta identificação de falhas no tratamento com laminados cerâmicos. Objetivo:Relatamos o uso da tomografia de coerência óptica (TCO) para avaliação da adaptação e reparo de uma reabilitação oral estética com laminados cerâmicos. Relato de caso:Paciente do sexo feminino, 24 anos, queixou-se de alteração de cor em laminado cerâmica cimentado no incisivo central superior direito. O exame clínico evidenciou alterações de cor entre os terços médio e incisal da superfície mesial do dente. As imagens obtidas por TCO mostraram a presença de bolhas ou gaps na interface adesiva da região. O plano de tratamento consistiu no reparo mediante infiltração de uma resina composta no local indicado pela TCO. Conclusão: A tomografia de coerência óptica se mostrou um método auxiliar eficaz para análise da adaptação do laminado cerâmico no incisivo superior direito. (AU)

Evaluation of marginal sealing quality of restorations with low shrinkage composite resins.

BACKGROUND: This study compared the quality of marginal sealing in the gingival wall of class II preparations of two low-shirinkage resins of the bulk fill type with a conventional resin isolated or associated with a glass ionomer cement (GIC). MATERIAL AND METHODS: 40 human molars were divided into 4 groups and 80 occlusal-mesial and occlusal-distal restorations were performed with the following materials: SureFil SDR flow, Filtek Bulk Fill Posterior, Z250 resins and Riva Light Cure GIC. 40 restorations were evaluated in Scanning Electron Microscopy (SEM) with Elemental Microanalysis Spectrometry (EDS) initially and the remainder after a period of 6 months of aging in a 37 ± 5°C oven. An average of the silver penetration at each restoration was obtained in the two evaluations and the results were statistically analyzed in a descriptive and inferential way, through the paired t-Student and one-way ANOVA F-test. RESULTS: There were no significant statistical differences between the materials with respect to silver nanoinfiltration, except for the Bulk Fill Posterior/3M ESPE resin compared to the GIC and conventional resin in the final evaluation. CONCLUSIONS: The low shrinkage resins showed a similar behavior in relation to the marginal sealing quality observed in the GIC or composite resin with the incremental technique, also presenting the advantage of simplicity in the technique of confection of the restorations and reduction of the time of work. Key words:Resin composites, Bulk fill, dental restorations, marginal quality, adhesion.

In vivo optical coherence tomographic imaging to monitor gingival recovery and the adhesive interface in aesthetic oral rehabilitation: A case report.

The available methods for veneer evaluation are limited to clinical and radiographic examinations, which may not allow the appropriate identification of failure. In this report, we demonstrate the use of optical coherence tomography (OCT) as a noninvasive diagnostic and follow-up method to evaluate gingival recovery and the adhesive interface in aesthetic oral rehabilitation involving periodontal plastic surgery and ceramic laminate veneers. OCT was efficient for evaluating both soft and hard tissues, as well as the quality of the adhesive interface. In conclusion, OCT was found to be a promising approach for the professional evaluation of aesthetic oral rehabilitation, as it was capable of generating images that enabled the analysis of gingival recovery and the adhesive interface.

In vivo assessment of periodontal structures and measurement of gingival sulcus with Optical Coherence Tomography: a pilot study.

There has been increasing interest on the development of clinically acceptable, more sensitive and specific methods for non-invasive diagnosis in Periodontics. In this pilot study, the performance of an Optical Coherence Tomography (OCT) system in imaging periodontal structures in humans was evaluated. Gingival sulcus depth measurements were obtained and compared with traditional probes. In total, 445 sites of 23 periodontally healthy individuals were measured by 3 instruments: North Carolina manual probe, Florida automated probe and OCT at 1325 nm. To obtain quantitative measurements from OCT images, the gingival refractive index was also determined. Discomfort/pain perception and the duration of examinations were compared among the instruments. The analysis of OCT images allowed the identification of relevant anatomic dental and periodontal regions. The average sulcus depth measured by OCT, 0.85 ± 0.27 mm and 0.87 ± 0.28 mm, was lower than the values obtained by manual and automated probing. Discomfort/pain were prevalent for traditional probes, which are invasive methods, than for the non-invasive OCT technique. OCT has the potential to be a reliable tool for in vivo periodontal tissues evaluation and for reproducible sulcus depth measurements in healthy sites. Further technological advances are required to reduce the procedure time and promote evaluation of posterior oral regions. Photonic assessment of periodontal tissue with OCT (top) in a clinical environment, showing tooth/gingiva features (bottom).

Radiopacity of resin cements: in vitro study / Radiopacidade de cimentos resinosos: estudo in vitro

Objective: To evaluate the radiopacity of seven different resin cements, noting whether they are in accordance with the requirements of ANSI/ADA no. 27/1993 and ISO no. 4049/2000, comparing the conventional radiographic system with digital (phosphor plate). Methods: For each material, five samples were prepared that were irradiated and tested in both systems; the optical density of the cement and each step-wedge of the penetrometer were measured. From the resulting values, the equivalent for each mm of aluminum material was obtained.Results: We found the lowest values in AllCem-FGM, Joinville, Brazil (2.06 and 4.63 Eq mmAl), and the highest values in the Fill Magic Dual Cement-Vigodent, Rio de Janeiro, Brazil (4.03 and 9.20 mmAl eq). Through the F-test (ANOVA) with two factors, a significant difference was confirmed between the two system types (p <0.05) and between cements (p <0.05). On the other hand, the interaction between type of system and cement was not significant (p> 0.05). Through the Tukey test, a significant difference was found between the cement Fill Magic Dual Cement (Vigodent, Rio de Janeiro, Brazil) and each of the other cements: AllCem (FGM, Joinville, Brazil), Cement Post (Angelus, Londrina, Brazil), RelyX Unicem (3M ESPE, St. Paul, MN, USA), SET (SDI, Victoria, Australia), regardless of the system. Conclusion: All cements fell within the standards, where the AllCem (FGM, Joinville, Brazil) had the lowest value of radiopacity and Fill Magic Dual Cement (Vigodent, Rio de Janeiro, Brazil) the highest, irrespective of the type of system.

Objetivo: Avaliar a radiopacidade de sete cimentos resinosos diferentes, observando se os mesmos encontram-se de acordo com as normas da ANSI / ADA n. 27/1993 e ISO n. 4049/2000, comparando-se o sistema radiográfico convencional com o digital (placa de fósforo). Métodos: Para cada material confeccionaram-se cinco amostras, que foram irradiadas, e analisadas em ambos os sistemas, mediram-se a densidade óptica dos cimentos e de cada degrau do penetrômetro. A partir dos valores encontrados obteve-se o equivalente em milímetros de alumínio para cada material. Resultados: Constatou-se menores valores no AllCem-FGM, Joinville, Brasil (2,06 e 4,63 Eq mmAl), e maiores no Fill Magic Dual Cement-Vigodent, Rio de Janeiro, Brasil (4,03 e 9,20 Eq mmAl) . Através do teste F (ANOVA) com dois fatores se comprovou diferença significativa entre os dois tipos de sistema (p < 0,05) e entre os cimentos (p < 0,05). Por outro lado, a interação do tipo de sistema e cimento não se mostrou significativa (p > 0,05). Através do teste de Tukey se evidenciou diferença significativa entre o cimento Fill Magic Dual Cement (Vigodent, Rio de Janeiro, Brasil) com cada um dos cimentos: AllCem (FGM, Joinville, Brasil), Cement Post (Angelus, Londrina, Brasil), RelyX Unicem (3M ESPE, Saint Paul, EUA), seT (SDI, Victória, Austrália), independente do tipo de sistema.Conclusão: Todos os cimentos estavam dentro das normas, onde o AllCem (FGM, Joinville, Brasil) apresentou menores valores de radiopacidade e o Fill Magic Dual Cement (Vigodent, Rio de Janeiro, Brasil) os maiores, independente do tipo de sistema.