Further Interventions after Root Canal Treatment Are Most Common in Molars and Teeth Restored with Direct Restorations: A 10-11-Year Follow-Up of the Adult Swedish Population.

INTRODUCTION: The aims were to investigate 1) the frequency of nonsurgical retreatment, root-end surgery, extraction, and further restorative treatment during a follow-up of 10-11 years after root filling and compare the frequencies according to tooth group and type of coronal restoration and 2) the timing of nonsurgical retreatment, root-end surgery, and extraction. METHODS: Data were collected from the Swedish Social Insurance Agency's register. A search for treatment codes identified teeth root filled in 2009 and the type of coronal restoration (direct, indirect, and unspecified) registered within 6 months of root filling. The root-filled teeth were followed 10-11 years, and further interventions were recorded. Descriptive statistics and chi-square tests were used for statistical analysis. RESULTS: In 2009, root fillings were registered for 215,611 individuals/teeth. Nonsurgical retreatment, root-end surgery, and extraction were undertaken in 3.5%, 1.4%, and 20% teeth, respectively. The frequency of further interventions varied with respect to tooth group and type of coronal restoration, but only slightly for endodontic retreatments. Further interventions, except for root-end surgery, were registered more often for molars and directly restored teeth (P < .001). The majority of endodontic retreatments were undertaken within 4 years, while extractions were evenly distributed over 10-11 years. CONCLUSIONS: The frequency numbers of nonsurgical retreatment and root-end surgery were low, despite 1 in 5 root-filled teeth registered as extracted. Further interventions were most common in molars and directly restored teeth. Endodontic retreatments were performed more often during the first 4 years.

Opinions of UK General Dental Practitioners on the Restoration of Posterior Root Filled Teeth: a Vignette Survey.

OBJECTIVE: To investigate factors which influence UK general dental practitioners (GDPs) when restoring posterior root filled teeth. METHOD: An electronic survey was designed to explore current strategies of treatment of posterior root filled teeth by UK-based GDPs working in primary care. Three vignette cases included in the questionnaire explored a variety of tooth, patient, and financial factors. The survey was distributed by email and social media platforms between December 2018 and February 2019. RESULTS: A total of 528 valid responses were collected. The majority of participants (84.1%) regularly restored posterior root filled teeth with an indirect restoration. Presence of persistent symptoms post root canal treatment (RCT) completion would impact the management of 85% of the surveyed respondents. Referral to a specialist, deferral of provision of the definitive restoration, and fear of litigation were reported by the GDPs as influencing factors. CONCLUSION: This survey highlights that decision making regarding restoration of root filled teeth is a multifactorial process. Tooth, patient, and financial factors were all shown to influence the restorative management of the posterior root filled teeth.

Could bulk fill glass hybrid restorative materials replace composite resins in treating permanent teeth? A randomized controlled clinical trial.

OBJECTIVE: This study aims to compare the clinical and radiographic efficacy of Equia system bulk fill glass hybrid material with composite resins in the permanent restoration of pediatric patients' permanent teeth. MATERIALS AND METHODS: The study included 44 pediatric patients aged 8-16 who applied to Necmettin Erbakan University Pediatric Dentistry Department. The groups were formed as symmetrical teeth in the same patient using the split-mouth design. The study included class I caries lesions of 144 permanent teeth. Group 1 was restored with the Equia system bulk fill glass hybrid material (Equia Forte HT + Equia Forte Coat [GC, Co, Tokyo, Japan]) (n = 72) and Group 2 with the Charisma Smart universal composite resin (Kulzer, Gmbh, Hanau, Germany) + Clearfil SE Bond (Kuraray, Noritake, Sakazu, Okayama) (n = 72). Evaluations were performed clinically and radiographically by two physicians in 2nd week, 3rd month, 6th month, and 12th month and the results were recorded. Clinical evaluation was carried out using modified-USPHS criteria. Obtained data were statistically analyzed using Kendall's W test and Cochran's Q test for the comparison within the group, and the Chi-square test for the comparison between groups. RESULTS: Among the materials utilized in the study, there was no statistically significant difference in marginal adaptation, marginal discoloration, retention, anatomical form, postoperative sensitivity, and secondary caries according (p > 0.05). Group 2 outperformed statistically significant Group 1 in terms of color match in all periods (p < 0.05). While there was no statistically significant difference in surface structure between the groups in 2nd week and 3rd month (p > 0.05), there was a statistically substantial difference in 6th, and 12th months (p < 0.05). No secondary caries or periapical lesions were found in any restorations during radiographic evaluation. CONCLUSION: After a year, the clinical performance of both Equia and composite resins was equivalent and successful in the majority of the measures against which they were evaluated. CLINICAL SIGNIFICANCE: Based on the results of the research, Equia system bulk fill glass hybrid restorations are considered a viable alternative to composite resins in class I permanent teeth restorations.

The influence of foundation restoration type and ceramic thickness on the final color of zirconia-reinforced lithium silicate ceramic.

Background: Similarity in the appearance of a monolithic restoration with the adjacent teeth is necessary. This study aims to influence the foundation material type and ceramic thickness on the final color of zirconia-reinforced lithium silicate (ZLS) ceramic. Materials and Methods: In this experimental study, the A2 translucent blocks of ZLS were sectioned into rectangular specimens with thicknesses 1, 1.5, and 2 mm (n = 15). Substructure materials include resin composite (B1, D2, A2, A3, and C3), nickel chrome alloy, amalgam, and white and black substrate. Substructure material of resin composite with A2 color was proposed as the control group. The value of the color difference (ΔE00) is calculated by the CIEDE2000 formula. Data analysis was accomplished by two-factor repeated measures ANOVA and one-sample t-test (α =0.05). Results: The mean value of maximum ΔE00 with a black substrate (12.13 ± 0.17) at 1 mm ceramic thickness and the mean value of minimum ΔE00 with B1 resin composite foundation material (0.02 ± 0.17) at 2 mm ceramic thickness are visible. The significant effect of the foundation restoration type, thickness, and interaction between them is visible on ΔE00 (P < 0.001). Conclusion: Different thickness is required to meet ideal esthetic outcomes with different substrates. Under the conditions of this investigation, zirconia-reinforced lithium silicate over black, white, nickel-chromium, and amalgam did not meet acceptable outcomes.

Effect of bioactive glass-containing dentin adhesives on microshear bond strength of composite restorations.

Background: In general, bioactive glasses (BAGs) can react with tissue minerals and promote remineralization. However, the application of BAG in bonding agents and its impact on bond strength remain uncertain due to insufficient information and limited research in this area. Materials and Methods: This study employed a randomized controlled design to assess the effects of composite-bonding agents with varying BAG contents on shear bond strength and fracture pattern in sound and demineralized teeth, with and without thermocycling. Thus, 80 healthy third molars were randomly divided into two groups: sound teeth and demineralized teeth. Five bonding agents were applied to the prepared dentin surfaces, including four experimental composite-bonding agents with varying BAG content (0, 0.2, 0.5, and 2 wt%) and the Adper Single Bond commercial bonding as control. The shear bond strength of all samples was measured using a universal tester. The type of failure of each specimen was determined using a stereomicroscope. Kruskal-Wallis nonparametric test was performed on the obtained shear bond strength data followed by Mann-Whitney post hoc test with Bonferroni correction to determine statistical significance. The level of significance was considered P ≤ 0.05 for all tests and was adjusted by Bonferroni correction. Results: Demineralization significantly decreased shear bond strength in the teeth samples. Adper Single Bond exhibited the highest shear bond strength values. The addition of BAG did not have a significant influence on shear bond strength, regardless of demineralization or thermocycling condition. Adhesive failure was the predominant type of failure in all groups. Conclusion: The incorporation of BAG filler up to 2 wt% did not result in significant changes in shear bond strength. Experimental adhesive bonding agents with 2 wt% BAG content demonstrated shear bond strengths comparable to the commercial bonding agent in sound nontreated, sound thermocycled, demineralized nontreated, and demineralized thermocycled groups.

Fatigue and marginal adaptation of bulk fill restoratives: Effect of the layering technique and cavity dimension of extensively damaged teeth.

OBJECTIVES: To evaluate the effect of layering technique and cavity dimension on the fatigue behavior and marginal adaptation of bulk fill (BF) restorations in extensively damaged teeth. METHODS: Seventy-two premolars received class II cavities (MOD) followed by endodontic treatment. Half sample had 1/3 of their palatal cusp removed. Teeth were restored using three techniques: (I) incremental, with conventional resin composite (RC); (C) combined, using BF flow and RC, (B) bulk fill, with regular BF. Specimens were subjected to fatigue (80 N, 2 Hz, 37° C water) for 1 million cycles (n = 12). The test was interrupted every 250,000 cycles to evaluate tooth integrity, restoration fracture and adaptation using FDI criteria. Images of the proximal surfaces were obtained before and after the cycling to measure the gap. Restoration fatigue survival and success were analyzed using Weibull distribution and Maximum Likelihood Estimation. Gap thickness was analyzed with Kruskal-Wallis and Student-Newman-Keuls tests (α = 0.05). RESULTS: For the survival analysis, Weibull modulus (ß) and characteristic lifetime (η) were similar among groups. Yet, for the success analysis, in which only restorations that were free of technical complications were ranked as success, the bulk-fill technique resulted in higher ß, while the combined technique produced restorations with higher η, for teeth that had their cusp removed. C-technique also resulted in smaller gaps than I and B. SIGNIFICANCE: The effect of the layering technique on the success of restorations was dependent on the cavity extension. The combined technique favors the adaptation and the longevity of extensively damaged teeth.

Ceramic versus Composite Resin Polishing Systems on the Surface Roughness of Milled Leucite-Reinforced Ceramics.

Background and Objective: This study aimed to compare the surface finish of milled leucite-reinforced ceramics polished with ceramic and composite polishing systems based on the manufacturers' recommendations. Materials and Methods: Sixty subtractive computer-aided manufactured (s-CAM) leucite-reinforced glass-ceramic specimens (IPS-Empress-CAD) were assigned into six groups: no polishing, a ceramic polishing kit, and four composite kit groups. The roughness average (Ra) was evaluated in microns using a profilometer, and scanning electron micrographs were obtained for qualitative analysis. A Tukey HSD posthoc test (α = 0.05) was used to determine significant intergroup differences. Results: After surface evaluation of the ceramics, the Ra values of the polishing systems ranked OptraFine (0.41 ± 0.26) < Enhance (1.60 ± 0.54) < Shofu (2.14 ± 0.44) < Astropol (4.05 ± 0.72) < DiaComp (5.66 ± 0.62) < No Polishing (5.66 ± 0.74). Discussion: Composite polishing systems did not provide as smooth surfaces as the ceramic polishing kit for CAD-CAM leucite-reinforced ceramics. Thus, using ceramic polishing systems, polishing leucite ceramics is recommended, whereas composite polishing systems should not be considered as an alternative for use in minimally invasive dentistry.

Soft Tissue Grafting Procedures before Restorations in the Esthetic Zone: A Minimally Invasive Interdisciplinary Case Report.

An esthetically pleasing smile is a valuable aspect of physical appearance and plays a significant role in social interaction. Achieving the perfect balance between extraoral and intraoral tissues is essential for a harmonious and attractive smile. However, certain intraoral deficiencies, such as non-carious cervical lesions and gingival recession, can severely compromise the overall aesthetics, particularly in the anterior zone. Addressing such conditions requires careful planning and meticulous execution of both surgical and restorative procedures. This interdisciplinary clinical report presents a complex case of a patient with esthetic complaints related to asymmetric anterior gingival architecture and severely discolored and eroded maxillary anterior teeth. The patient was treated using a combination of minimally invasive ceramic veneers and plastic mucogingival surgery, resulting in a successful outcome. The report emphasizes the potential of this approach in achieving optimal esthetic results in challenging cases, highlighting the importance of an interdisciplinary team approach in achieving a harmonious balance between dental and soft tissue aesthetics.

An Innovative 3D Printed Tooth Reduction Guide for Precise Dental Ceramic Veneers.

Tooth reduction guides allow clinicians to obtain the ideal space required for ceramic restorations. This case report describes a novel design (CAD) for an additive computer-aided manufactured (a-CAM) tooth reduction guide with channels that permitted access for the preparation and evaluation of the reduction with the same guide. The guide features innovative vertical and horizontal channels that permit comprehensive access for preparation and evaluation of the reduction with a periodontal probe, ensuring uniform tooth reduction and avoiding overpreparation. This approach was successfully applied to a female patient with non-carious lesions and white spot lesions, resulting in minimally invasive tooth preparations and hand-crafted laminate veneer restorations that met the patient's aesthetic demands while preserving tooth structure. Compared to traditional silicone reduction guides, this novel design offers greater flexibility, enabling clinicians to evaluate tooth reduction in all directions and providing a more comprehensive assessment. Overall, this 3D printed tooth reduction guide represents a significant advancement in dental restoration technology, offering clinicians a useful tool for achieving optimal outcomes with minimal tooth reduction. Future work is warranted to compare tooth reductions and preparation time for this guide to other 3D printed guides.

Impact of Irradiation on the Adhesive Performance of Resin-Based Dental Biomaterials: A Systematic Review of Laboratory Studies.

Head and neck cancers are a significant global health burden, with radiation therapy being a frequently utilized treatment. The aim of this systematic review was to provide a critical appraisal of laboratory studies that assessed the effect of irradiation on the adhesive performance of resin-based biomaterials. The analysis included 23 laboratory studies obtained from five databases, with most studies using human enamel, dentin, or both, and bonding procedures involving the fabrication of direct restorations, standardized specimens, bonding of orthodontic brackets, and luting of endodontic fiber posts. The protocols used for irradiation varied, with most studies exposing specimens made from extracted teeth to irradiation using cabinet irradiators to simulate treatment of head and neck cancer. The findings indicate that irradiation reduces the bond strength of dental adhesives and resin-based composites on flat, ground enamel and dentin specimens, with different adhesives and timing of irradiation having a significant impact on adhesive performance. Irradiation also increased microleakage in most studies. The effect of irradiation on marginal adaptation of direct resin-based composite restorations was inconclusive. This systematic review indicates that irradiation has detrimental effects on the adhesive performance of resin-based biomaterials and highlights the need for further clinical and laboratory studies evaluating the performance of adhesive materials and approaches to improve it.

Surface smoothness of resin composites after polishing-A systematic review and network meta-analysis of in vitro studies.

A systematic review and network meta-analysis was performed to provide evidence for the best polishing protocol for different types of resin composites to minimize surface roughness. A search was performed in PubMed, Scopus, Web of Science, LILACS, BBO, EMBASE, and Cochrane Library on July 2, 2019 (updated in December, 2020). In vitro studies that included at least two systems for polishing resin composites and analyzed surface roughness were included. The risk of bias was evaluated. A random-effects Bayesian-mixed treatment comparison model was used to compare surface roughness in resin composites with the different types of polishers. Surface under the cumulative ranking curve (SUCRA) analysis was performed to rank the probability for the best polishing system. After removal of duplicates, title and abstract screening yielded 34 studies. Network meta-analysis was not possible for hybrid and microhybrid composites. SUCRA analysis showed that abrasive paper discs allowed greater surface smoothness for nanohybrid and nanofill composites to a probability of between 83% and 91.6%. Silicon carbide brush had a 78.2% probability of being the best system for microfill composites. The use of abrasive paper disc polishers showed a favorable result in nanofill and nanohybrid resin composites. Silicon carbide brush has a greater chance of promoting a smoother surface for microfill resin composites.

Sistemas de pulido para restauraciones cerámicas. Revisión de la literatura / Polishing systems for ceramic restorations. Literature review

El pulido es un paso de suma importancia en el flujo de trabajo de las restauraciones cerámicas, después de realizado un ajuste con puntas o piedras diamantadas, ya que disminuye la rugosidad de las superficies tratadas. Esto repercute positivamente en las propiedades mecánicas y ópticas del material. Sin embargo, la poca literatura disponible acerca de este procedimiento hace que sea pasado por alto. Debido a esto, el presente articulo tuvo como objetivo realizar una revisión bibliográfica sobre los diferentes protocolos de pulido para las diversas restauraciones cerámicas de mayor uso: Feldespática, disilicato de litio y zirconia en sus diferentes presentaciones. Se describen aspectos relevantes sobre el pulido mecánico, la rugosidad superficial y los sistemas de pulido actuales para cerámicas.

Polishing is an extremely important step in the workflow of ceramic restorations, after adjustment with diamond burs or stones, as it reduces the roughness of the treated surfaces. This has a positive impact on the mechanical and optical properties of the material; however, the limited literature available about this procedure makes it to be overlooked. Therefore, the aim of this article was to review the literature on the different polishing protocols for the most used ceramic restorations: Feldspathic, lithium disilicate and zirconia ceramics. Relevant aspects on mechanical polishing, surface roughness and current polishing systems for ceramics are described.

Clinical performance of an alkasite-based bioactive restorative in class II cavities: a randomized clinical trial

Abstract Objective This clinical study aimed to evaluate the clinical performance of an alkasite-based bioactive material by comparing it with a resin composite (RC) in the restoration of Class II cavities over a year. Methodology A hundred Class II cavities were restored at 31 participants. Groups were as follows: Cention N (CN) (Ivoclar Vivadent, Schaan, Liechtenstein) and G-ænial Posterior (GP) (GC, Tokyo, Japan) in combination with G-Premio Bond (etch&rinse). Restorative systems were applied following manufacturers' instructions. They were finished and polished immediately after placement and scored based on retention, marginal discoloration, marginal adaptation, sensitivity, surface texture, and color match using modified USPHS criteria after 1 week (baseline), 6 months, and 12 months. Statistical analyses were performed using chi-square, McNemar's, and Kaplan Meier tests. Results After 12 months, the recall rate was 87%. Survival rates of CN and GP restorations were 92.5% and 97.7%, respectively. Three CN and one GP restorations lost retention. Seven CN (17.9%) and five (11.6%) GP restorations were scored as bravo for marginal adaptation and no significant difference was seen between groups (p=0.363). One (2.7%) CN and two GP (4.7%) restorations were scored as bravo for marginal discoloration, but no significant difference was observed between groups(p=1.00). For surface texture, three (8.1%) CN and three (7%) GP restorations were scored as bravo (p=1.00). None of the restorations demonstrated post-operative sensitivity or secondary caries at any examinations. Conclusion The tested restorative materials performed similar successful clinical performances after 12 months. ClinicalTrials.gov (NTC04825379).

Ortodontia minimamente invasiva auxiliando a reabilitação estética dos incisivos superiores ­ relato de caso / Minimally invasive orthodontics can help aesthetic rehabilitation of the upper anterior teeth ­ a case report

Resumo Esse artigo descreve o tratamento de um diastema na região anterior da maxila utilizando uma abordagem multidisciplinar. Paciente do gênero feminino, 38 anos, procurou atendimento odontológico na Clínica Faculdade de Odontologia da Universidade Nove de Julho, com queixa estética devido ao diastema da linha média maxilar. Após exame clínico e tratamento periodontal, verificou-se a necessidade de alinhamento e nivelamento dos dentes anteriores. O excesso de papila gengival entre 11 e 21 foi submetido à exérese, e um aparelho ortodôntico fixo foi instalado em 12, 11, 21 e 22. Após três semanas, quando os dentes estavam posicionados em condições mais favoráveis, uma contenção Hawley foi adaptada para pequenas correções no sentido vestíbulo-lingual. Para a restauração dos dentes, foi feito um molde diagnóstico e enceramento para permitir a construção de uma matriz de silicone. Um compósito nano-híbrido e um micro-híbrido foram escolhidos e colocados seguindo a matriz de silicone ajustada ao lado palatino dos dentes. Após os procedimentos de acabamento e polimento, o resultado estético foi muito satisfatório tanto para o paciente quanto para a equipe odontológica. A relevância clínica desse caso indica que é possível treinar alunos de Graduação para alcançar o sucesso no tratamento de diastemas adversos da linha média em um curto período de tempo, com planejamento e interação entre diferentes especialidades odontológicas. (AU)

Abstract This manuscript described the treatment of anterior maxillary diastema using a multidisciplinary approach. A female patient, 38 years old, looked for dental treatment at the University Nove de Julho Dental School Clinic with an esthetic complaint due to maxillary midline diastema. After clinical examination and periodontal treatment, the necessity of alignment and leveling of the anterior teeth was verified. Excess of gingival papilla between 11 and 21 underwent exeresis and an orthodontic fixed appliance was installed in 12, 11, 21, and 22. After three weeks, when the teeth were positioned in a more favorable condition, a Hawley retainer was adapted for small corrections in buccolingual direction. For teeth restoration, a diagnostic cast and wax-up was made to allow the construction of a silicone matrix. A nanohybrid and a microhybrid composite were chosen and placed following the silicone matrix adjusted to the palatal side of the teeth. After finishing and polishing procedures, the esthetic result was very satisfactory for both the patient and the dental staff. The clinical relevance of this case indicates that it is possible to train undergraduate students to achieve success treating adverse midline diastema in a short period of time throw planning and interaction among different dental specialties (AU)

OPTIMAL RESTORATIVE OPTION FOR PERMANENT FIRST MOLARS AFFECTED BY HYPOMINERALIZATION REMAINS UNCERTAIN.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Restorative techniques for permanent first molars affected by hypomineralization: a systematic review. Lopes-Fatturi A, Wambier L, Rolim TZC, Reis A, Feltrin de Souza J. Pediatr Dent 2022; 44(1):17-24. SOURCE OF FUNDING: None. TYPE OF STUDY/DESIGN: Systematic review.

Effectiveness of glass ionomer cements in the restorative treatment of radiation-related caries - a systematic review.

PURPOSE: The aim of this systematic review was to investigate the clinical effectiveness of glass ionomer cements (GICs) compared to other restorative materials in the treatment of radiation-related caries. METHODS: Two independent researchers searched literature databases (PubMed, Scopus, Web of Science, Cochrane Library, Lilacs/BBO) and the grey literature to identify clinical trials that compared GICs with other restorative materials for the treatment of radiation-related caries. The clinical criteria considered for the performance of the restorations were based on the parameters of marginal adaptation/anatomical form, secondary caries, retention, and cumulative failures of the restorations. The methodological quality and risk of bias were evaluated using the Cochrane Collaboration tool. RESULTS: From a total of 511, only four articles fulfilled the inclusion criteria. Conventional GIC restorations presented higher marginal adaptation failures than the resin-modified glass ionomer cements (RM-GICs) and composite restorations in all of the follow-up periods. Secondary caries was not observed in conventional GIC restorations throughout the follow-up periods, in three out of four of the included studies. RM-GICs and composite restorations showed significantly lower cumulative failure rates than conventional GICs at 6-, 12-, and 18-month follow-ups. CONCLUSION: Due to insufficient scientific evidence, it was not possible to conclude that GICs are more effective than other restorative materials for the treatment of radiation-related caries.

Transfixação horizontal de pino de fibra de vidro em um dente tratado endodonticamente: relato de caso clínico / Horizontal transfixion of a fiberglass post into an endodontically treated tooth: a clinical case report

O objetivo deste relato de caso foi descrever em detalhes a técnica de transfixação de pino de fibra de vidro no sentido horizontal e restauração de resina composta em um dente molar tratado endodonticamete. Paciente, sexo feminino, 51 anos de idade, buscou o Centro Universitário da Serra Gaúcha (FSG ­ Caxias do Sul ­ Rio Grande do Sul) com a necessidade de realizar tratamento endodôntico do elemento molar número 26. Após a avaliação inicial, foi realizada a endodontia. O elemento havia pouca sustentação das paredes vestibular e palatina, então foi proposto a colocação de pino intrarradicular seguido de coroa, entretanto, por questões financeiras a paciente não aceitou. Logo, foi proposto a técnica de transfixação horizontal de pino de fibra de vidro associado a uma restauração de resina composta de forma direta. O procedimento foi realizado em sessão única e foi utilizado um pino de fibra de vidro número 1 disposto transversalmente entre as paredes mesiopalatina e distovestibular. A restauração foi realizada com resina composta Filtek Z350, devolvendo estética e função ao elemento dentário. Pode-se concluir que a técnica de transfixação horizontal de pino de fibra de vidro associado à resina composta é uma alternativa restauradora que possibilita maior resistência aos dentes tratados endodonticamente, apresenta resultados funcionais e estéticos satisfatórios, além de possibilitar uma maior sobrevida aos mesmos(AU)

The purpose of this case report was to describe in detail the technique of horizontal transfixion of a fiberglass post into an endodontically treated tooth. Female patient, 51 years old, sought the University Center of Serra Gaúcha (FSG - Caxias do Sul ­ Rio Grande do Sul) with the need to perform the endodontic treatment of molar element number 26. After the initial evaluation, endodontics was performed. The element had little support for the buccal and palatal walls, so an intraradicular postplacement followed by a crown was proposed, for financial reasons the patient did not accept it. Therefore, the technique of horizontal transfixion of a fiberglass pin was proposed, associated with a restoration of direct composite resin. The procedure was performed in a single session and a number 1 fiberglass post was fixed crosswise between the mesiopalatal and distobuccal walls. The restoration was carried out with composite resin Filtek Z350, restoring aesthetics and function. It can be concluded that the horizontal transfixion of a fiberglass post associated with composite resin technique is a restorative alternative that allows greater resistance to endodontically treated teeth, provides satisfactory esthetics and better survival rates(AU)

Influence of non-carious cervical lesions, bone attachment level, and occlusal load on the stress distribution pattern in maxillary premolars: finite element analysis

This study aimed to evaluate the influence of different bone attachment levels and occlusal loads on the stress distribution pattern of maxillary premolars with or without non-carious cervical lesion (NCCL), before and after restoration with composite resin by three-dimensional (3D) finite element analysis. From the healthy model, NCCL models were produced and the cavity was restored with composite resin. Models with vertical and horizontal bone loss were also made. For each model, three types of occlusal loads were simulated (100 N): vertical load (VL), buccal load (BL), and palatal load (PL). After processing the models, the data were obtained in MPa for the criteria of Maximum Principal Stress (for all structures) and Minimum Principal Stress (for cortical and medullary bones). Stress values were collected for a node on the cervical buccal surface (Maximum Principal Stress) and the buccal crestal bone (Minimum Principal Stress). As a result, the different bone attachment levels did not affect stress distribution at the amelodentinal junction. The buccal load promoted a higher concentration of compressive stress on the buccal bone surface and the palatal load resulted in greater tensile stress in the buccal cervical third of the tooth. The concentration of tensile stress in the buccal cervical third was exacerbated by the presence of NCCL and it was similar to the healthy and restored models. It can be concluded that stress concentration at the bone level does not depend on the presence or absence of NCCL and the restoration procedure but it is related to the type of occlusal load. However, the presence of NCCL promoted a higher stress concentration in the cervical region, especially when combined with oblique occlusal loads.

In-vitro fit of experimental full-arch restorations made from monolithic zirconia.

PURPOSE: Fabrication inaccuracies can compromise the fit of large-span monolithic zirconia restorations. Sintering distortion is a particular problem. This study aimed to assess the fit of full-arch restorations made from monolithic zirconia for different abutment configurations. METHODS: To quantify fit inaccuracies created during the fabrication of experimental large-span restorations, an in-vitro model with eight abutment teeth was equipped with strain gauges. Ten 14-unit restorations were made from monolithic zirconia and seated on the model in turn. For each of the ten restorations, measurements were taken for three different abutment configurations-polygonal, quadrangular, and unilaterally shortened. Strains exerted during seating were recorded in the anterior-posterior and buccal-palatal directions, and the resulting horizontal forces (rhF) were calculated along with the respective abutment deflection (ad). Data were analyzed using Kruskal-Wallis tests at a significance level of 0.05. RESULTS: All restorations could be seated on the multi-abutment model. The restorations exhibited fabrication misfits, tending to be too wide. Mean rhF/ad were largest for the quadrangular configuration (16.8±2.9 N/0.065 mm) and smallest for the polygonal configuration (13.6±4.5 N/0.053 mm). The largest rhF/ad were measured on abutments of the unilaterally shortened configuration, with a maximum deflection of 0.126 mm. For two of three configurations, rhF/ad were significantly larger for the distal abutments than for the other abutments. CONCLUSION: Even if milling and sintering procedures are optimum, misfit-induced horizontal forces cannot be avoided. Because of the natural tooth mobility, however, the fit of full-arch restorations made from monolithic zirconia might be clinically acceptable.

Fracture strength of extended class I composite restorations with different restorative techniques.

To evaluate the fracture strength of extended Class I restorations with different restorative techniques using nanofilled and nanohybrid composites. Sixty extracted human third molars were prepared with extended Class I cavities and divided into six groups: groups FS-F (Filtek bulk-fill Flow + Filtek Supreme Ultra, 3 M) and GR-F (X-tra base + GrandioSO, VOCO), restored with a flowable bulk-fill composite as a base covered by a nanofilled or nanohybrid composite; groups FB (Filtek One Bulk-Fill, 3 M) and AF (Admira Fusion X-tra, VOCO), restored with a bulk-fill resin composite; and groups FS (Filtek Supreme Ultra, 3 M) and GR (GrandioSO, VOCO), restored incrementally with a nanofilled or nanohybrid composite. Sound extracted teeth (n = 10) were used as a control group (CTL). The specimens were axially loaded until failure. Data were analyzed using one-way ANOVA and Games Howell test (α = 0.05). Groups CTL and GR-F demonstrated significantly higher mean fracture strength when compared to FS, AF, and GR (p < 0.05). Group AF obtained more repairable fractures than the other groups. Restorations made with a nanofilled bulk-fill composite or with conventional resin composites associated with a flowable bulk-fill base were able to reestablish the fracture strength to that of sound teeth.