Bio-active cements-Mineral Trioxide Aggregate based calcium silicate materials: a narrative review.

Recent advances in the field of endodontics have greatly improved the outcome and success rate of dental materials. For last three decades, there has been great interest in the development of bioactive dental material with the ability to interact and induce surrounding dental tissues to promote regeneration of pulpal and periradicular tissues. As these bioactive materials are mainly based on calcium silicates, they are also referred to as Calcium Silicate materials. The first material introduced was Mineral Tri-oxide Aggregate, which, due to its favourable biological properties, gained importance initially. However, later, due to its drawbacks, liked is colouration, long setting time and difficult manipulation, several modifications were done and newer bioactive materials, such as Biodentine, BioAggregate, Endosequence, Calcium-Enriched Mixture etc., were developed. The main applications of these materials are for pulp capping (direc t/indirec t), pulpotomy, perforation repair, resorption defects, apexogenesis and as retrograde filling materials, apexification and endodontic sealers. This review discusses the various types of bioactive materials, their composition, setting mechanism, and literature evidence for current applications.

Radiopacity and Chemical Assessment of New Commercial Calcium Silicate-Based Cements / Radiopacidad y Evaluación Química de Cementos Comerciales en Base a Silicato de Calcio

ABSTRACT: The aim of the study was to evaluate the chemical composition and radiopacity of new calcium-silicatebased cements. Discs of 10 mm x 1 ± 0.1mm were prepared of BiodentineTM, TheraCal, Dycal and GC Fuji IX (n=5). The samples were radiographed directly on an PSP occlusal plate adjacent to an aluminium step wedge. The radiopacity of each specimen was determined according to ISO 9917/2007. Statistical analyses were carried out using ANOVA and Tukey's test at a significance level of 5 %. The chemical constitution of materials was determined by scanning electron microscopy (SEM) and energy dispersive x-ray element mapping. The radiopacities of the materials in decreasing order were: GC Fuji IX (3.45 ± 0.16 mm), Dycal (3.18 ± 0.17), BiodentineTM (2.79 ± 0.22), and TheraCal (2.17 ± 0.17). TheraCal showed the lowest radiopacity compared to the other materials, followed by BiodentineTM. Dycal and GC Fuji IX radiopacity values did not present significant statistical differences. Scanning electron microscopy and energy dispersive X-ray analysis revealed the presence of zirconium in BiodentineTM; and strontium, barium and zirconium in TheraCal as radiopacifying elements. The new calcium silicate cements present distinctive chemical composition. BiodentineTM contains zirconium as a radiopacifying element and has higher radiopacity values than TheraCal, which contains barium and strontium as radiopacifiers.

RESUMEN: El objetivo de este estudio fue evaluar la composición química y la radiopacidad de nuevos cementos en base a silicato de calcio. Discos de 10 mm x 1 ± 0,1 mm fueron preparados con BiodentineTM, TheraCal, Dycal y GC Fuji IX (n=5). Las muestras fueron radiografiadas directamente en una película PSP oclusal adyacente a una cuña escalonada de aluminio. La radiopacidad de cada espécimen fue determinada de acuerdo a la norma ISO 9917/ 2007. Se realizaron los análisis estadísticos con las pruebas ANOVA y test de Tukey con un nivel de significancia de 5 %. La constitución química de los materiales fue determinada con microscopía electrónica de barrido y con mapeo por análisis con dispersión de energía de rayos X. La radiopacidad de los materiales en orden decreciente fue: GC Fuji IX (3,45 ± 0,16 mm), Dycal (3,18 ± 0,7 mm), BiodentineTM (2,79 ± 0,22 mm), y TheraCal (2,17 ± 0,17 mm). TheraCal mostró la menor radiopacidad comparada con los otros materiales, seguido de BiodentineTM. Los valores de radiopacidad de Dycal y GC Fuji IX no presentaron diferencias estadísticas significativas. Los análisis de microscopía electrónica de barrido y mapeo por análisis con dispersión de energía de rayos X revelaron la presencia de zirconio en BiodentineTM; y de estroncio, bario y zirconio en TheraCal, como elementos radiopacos. Los nuevos cementos en base a silicato de calcio presentan una composición química distintiva. BiodentineTM contienen zirconio como elemento que provee radiopacidad y tiene mayor valor de radiopacidad que TheraCal, el cual contiene bario y estroncio como agente radiopaco.

[Photoelastic analysis of the influence of prosthetic material on the stress distribution in bone around implant].

Objective: To provide a reference for a suitable alternative treatment choice for implant-supported prostheses, and to explore the influence of 3 types of prosthetic material on the stress distribution around implant. Methods: The implant-abutment analogs were embedded individually into photoelastic resin blocks, which were medical pure titanium castings reproducing the surface and outline of implant (diameter 4.3 mm, length 11.5 mm) and esthetic abutment (regular profile, 1 mm). The prostheses were divided into 3 groups according to the type of prosthetic material. Each group consisted of 5 samples. The samples of composite resin ceramic and zirconia group were milled by chair-side computer aided design and computer aided manufacture (CAD/CAM) system. The samples of porcelain-fused-to-metal crown group were made manually and a pre-arranged silicone rubber impression of CAD/CAM crown would guide to shape the veneer porcelain. Each set was submitted to a 300 N compressive load axially or obliquely (75°). The stress value in the peri-implant bone at the level of the neck, neck1/3, middle1/3 and root1/3 of the sections (0.5, 1.5, 2.5, 3.5 mm) from implant was analyzed by digital photoelasticity, and the stress cushioning effect of 3 types of prosthetic material was comprehensively evaluated. Results: The time spent reaching the stress peak of composite resin ceramic group [(1.58±0.08) s, axially; (2.75±0.21) s, obliquely] was larger than that of the zirconia group [(1.40±0.12) s, axially; (2.30±0.25) s, obliquely] (P<0.05) under the same download mode. Although there were no significant differences in equivalent stress values of the measurement points among the three groups (P>0.05), a downward trend of equivalent stress values of composite resin ceramic group was observed compared to zirconia group, regardless of load type. When loaded obliquely, the highest degree of stress concentration at the level of the neck of implant were found in the porcelain-fused-to-metal crown group. Conclusions: Within the limitations of this study, composite resin ceramic was more beneficial to the biomechanical behavior of implant in stress buffer compared to zirconia.

Study of Two-Body Wear Performance of Dental Materials.

INTRODUCTION: The purpose of this study was to evaluate the two-body wear resistances of natural enamel and four dental materials in vitro. METHODS: The testing machine was modified to form a type of pin-on-disk wear test apparatus. Four dental material specimens (Au-Pd alloy, Ag-Pd alloy, FiltekTMP60 and FiltekTMZ350 composite resins) and enamel were used as the pins, and a steatite ceramic grinding wheel was used as the abrasive counter face. The wear volume loss and the rigidity value was measured. The worn surface and the element analysis of the debris were analyzed. RESULT: The wear volume loss of Au-Pd alloy and its steatite antagonists were the nearest to those of the dental enamel. SEM microphotographs showed that, the main wear mechanism of the dental materials was abrasive and adhesive wear. CONCLUSIONS: Au-Pd alloy had good wear resistance and was more suitable for dental applications than other three dental materials.

Does Classification of Composites for Network Meta-analyses Lead to Erroneous Conclusions?

OBJECTIVES: Composites can be classified differently, according to manufacturer information, filler particle size, resin-monomer base, or viscosity, for example. Using clinical trial data, network meta-analyses aim to rank different composite material classes. Dentists then use these ranks to decide whether to use specific materials. Alternatively, annual failure rates (AFRs) of materials can be assessed, not requiring any classification for synthesis. It is unclear whether different classification systems lead to different rankings of the same material (ie, erroneous conclusions). We aimed to evaluate the agreement of material rankings between different classification systems. METHODS: A systematic review was performed via MEDLINE, Cochrane Central Register of Controlled Trials, and EMBASE. Randomized controlled trials published from 2005-2015 that investigated composite restorations placed in load-bearing cavitated lesions in permanent teeth were included. Network meta-analyses were performed to rank combinations of composite classes (according to manufacturer, filler particle size, resin-monomers, viscosity) and adhesives. Material combinations were additionally ranked using AFRs. RESULTS: A total of 42 studies (6088 restorations, 2325 patients) were included. The ranking of most material class combinations showed significant agreement between classifications ( R2 ranged between 0.03 and 0.56). Comparing material combinations using AFRs had low precision and agreement with other systems. AFRs were significantly correlated with follow-up periods of trials. CONCLUSION: There was high agreement between rankings of identical materials in different classification systems. Such rankings thus allow cautious deductions as to the performance of a specific material. Syntheses based on AFRs might lead to erroneous results because AFRs are determined by follow-up periods and have low precision.

Higher experience of caries and lower income trajectory influence the quality of restorations: A multilevel analysis in a birth cohort.

OBJECTIVES: This study aimed to evaluate the quality of posterior restorations (amalgam or composite) placed in adults from a birth cohort and its association with clinical and socioeconomic determinants experienced during their life course. METHODS: A representative sample (n=539) of all 5914 births occurring in Pelotas (Brazil) in 1982 was prospectively investigated. Quality of posterior restorations (satisfactory or unsatisfactory) was assessed at 31 yrs-old, using modified USPHS criteria. Trained and calibrated dentists performed clinical examination. Explanatory variables included demographic and socioeconomic, oral health and dental service utilization patterns during the life course. Tooth related variables (type of tooth, material, size of cavity) were also analyzed. Untreated caries and socioeconomic status were assessed by group-based trajectories analyses. Multilevel Regression models were used to determine factors associated with restoration outcomes. RESULTS: In total 2123 restorations (53% composite) were evaluated of which 107 (5%) were assessed as failed. The main reasons for failure were tooth/restoration fracture (50.5%) and secondary caries (30.7%). Failures in posterior restorations showed a significant association with socioeconomic aspects (lower tertile of income at age 30 - prevalence ratio (PR) 2.21 [95% CI 1.19-4.09]), clinical variables (trajectory of higher untreated caries - PR 2.11 [95% CI 1.23-3.61]) and also with tooth-related factors (Restorations involving three or more surfaces - PR 5.51 [95% CI 3.30-9.19]) after adjustment for each other. CONCLUSIONS: These findings suggest that, although tooth-related variables have an important role in restoration longevity, patient-related factors, such as socioeconomic variables and untreated caries are also associated with failure and should be taken into account when evaluating longevity of posterior restorations. CLINICAL SIGNIFICANCE: This was the first study assessing long-term trajectory of untreated caries, showing an association between higher experience of caries during the life-course and unsatisfactory restorations. The findings suggest that individual related factors should be considered when planning treatment and in future research evaluating the longevity of dental restorations.

Tratamento reabilitador cirúrgico restaurador: relato de caso / Surgical-restoring rehabilitator treatment: a case report

Tendo em vista a abundância de procedimentos realizados envolvendo a inter-relação entre a Dentística Restauradora e Periodontia na Odontologia contemporânea, é preciso salientar a importância da realização de técnicas cirúrgica e restauradora corretas por parte dos cirurgiões-dentistas, assim como na conceitualização de que os tecidos periodontais podem reagir de forma positiva à presença de materiais restauradores adesivos posicionados apicalmente à gengiva, sem a necessidade da recuperação do espaço biológico. O presente estudo teve como objetivo demonstrar a técnica da realização de uma restauração transcirúrgica através de um relato de um caso clínico realizado no Complexo Odontológico do Centro Universitário da Serra Gaúcha (FSG). A paciente foi diagnosticada com uma cavidade subgengival no elemento 16 e submetida à procedimento restaurador transcirúrgico, sendo o ionômero de vidro fotopolimerizável o material restaurador de eleição. Este trabalho evidenciou como os tecidos periodontais podem reagir de maneira positiva à presença de materiais biocompatíveis resultando, inclusive, em um remodelamento ósseo favorável. (AU)

Considering the abundance of procedures performed involving the Restorative Dentistry and Periodontics relationship in contemporary dentistry, it is necessary to emphasize the importance of performing a correct surgical and restorative technique by dental surgeons, as well as in the conceptualization that periodontal tissues can react positively in the presence of adhesive restorative materials positioned apically to the gingiva, without the need of the recovery of the biological width. The present study aims to demonstrate the technique of performing a trans-surgical restoration through a clinical case report performed at the Odontological Complex of Centro Universitário da Serra Gaúcha (FSG). The patient was diagnosed with a subgingival cavity in element 16, underwent a trans-surgical procedure, the light-curing glass ionomer being the restorative material of choice. This work evidenced how the periodontal tissues can react in a positive way in the presence of biocompatible materials, resulting also in a favorable bone remodeling.(AU)

Own brand label restorative materials-A false bargain?

OBJECTIVES: This study aims at evaluating and comparing mechanical, chemical, and cytotoxicological parameters of a commercial brand name composite material against two 'own brand label' (OBL) composites. METHODS: Parameters included depth of cure, flexural strength, degree of conversion, polymerization shrinkage, filler particle morphology and elemental analyzes, Vickers hardness, surface roughness parameters after abrasion, monomer elution, and cytotoxicity. RESULTS: The conventional composite outperformed the OBLS in terms of depth of cure (p<0.001), degree of cure at the first and last time intervals (p<0.001), hardness (p<0.001), and post-abrasion roughness (p<0.05). The polymerization volumetric shrinkage ranged from 2.86% to 4.13%, with the highest shrinkage seen among the OBLs. Both Monomer elution from the OBLs was statistically significantly higher (p<0.001). Statistically significantly higher cytotoxicity combined with altered morphology and loss of confluence was detected in the cells exposed to extracts from the OBLs. CONCLUSIONS: The OBLs were in general outdone by the conventional composite. CLINICAL SIGNIFICANCE: OBLs restorative materials have become pervasive in the dental market. Manufacturers often promise equal or better characteristics than existing brand-name composites, but at a lower price. Dentists are highly recommended to reconsider utilization of OBLs lacking sound scientific scrutiny, and our findings underscore this recommendation.

Tiempo de vida de las restauraciones dentales libres de metal: revisión sistemática / Lifetime of metal-free dental restorations: a systematic review

En la actualidad existen muchos materiales dentales para la restauraciónestética, sin embargo, su tiempo de vida clínico no se conoce ampliamente. Objetivo: Identificar las publicaciones recientes de los materiales de restauración libre de metal que incluyan estudios clínicos. Metodología: La búsqueda sistemática de la literatura se realizó en bases de datos de PubMed y SciELO; se consideraron publicacionesdel 2010-2015 y que fueran investigaciones clínicas exclusivamente.Las palabras clave utilizadas fueron: Veneer crowns, dental restorationsfree metal, metal free crowns, aesthetic crowns y restauraciones libres de metal, coronas de silicato de litio, tipos de cerámicas. Resultados: Se revisaron 40 artículos y 20 cumplieron con los criterios de selección para la revisión bibliográfica. Todas las restauraciones protésicas libres de metal muestran un desempeño clínico muy similar a los tres años. Las restauraciones de zirconia y disilicato de litio por CAD mostraronel mejor éxito clínico. Conclusión: El éxito clínico de las restauracioneslibres de metal de esta revisión de la literatura muestra que van de un92.7 al 100 por ciento a tres o más años de seguimiento...

Root Caries in Older Adults.

Older adults are retaining an increasing number of natural teeth, and nearly half of all individuals aged 75 and older have experienced root caries. Root caries is a major cause of tooth loss in older adults, and tooth loss is the most significant negative impact on oral health-related quality of life for the elderly. The need for improved preventive efforts and treatment strategies for this population is acute.

Hybrid materials offer new perspectives.

Dental materials, especially in restorative dentistry, must not only be cost-effective, they must also meet many other requirements: biocompatibility, durability, excellent shade and light effects, abrasion resistance, hardness, mechanical strength under pressure, chemical resistance, surface density, ease of manufacture, and easy intraoral maintenance.

Updating Classifications of Ceramic Dental Materials: A Guide to Material Selection.

The indications for and composition of today's dental ceramic materials serve as the basis for determining the appropriate class of ceramics to use for a given case. By understanding the classifications, composition, and characteristics of the latest all-ceramic materials, which are presented in this article in order of most to least conservative, dentists and laboratory technicians can best determine the ideal material for a particular treatment.

A new classification system for all-ceramic and ceramic-like restorative materials.

Classification systems for all-ceramic materials are useful for communication and educational purposes and warrant continuous revisions and updates to incorporate new materials. This article proposes a classification system for ceramic and ceramic-like restorative materials in an attempt to systematize and include a new class of materials. This new classification system categorizes ceramic restorative materials into three families: (1) glass-matrix ceramics, (2) polycrystalline ceramics, and (3) resin-matrix ceramics. Subfamilies are described in each group along with their composition, allowing for newly developed materials to be placed into the already existing main families. The criteria used to differentiate ceramic materials are based on the phase or phases present in their chemical composition. Thus, an all-ceramic material is classified according to whether a glass-matrix phase is present (glass-matrix ceramics) or absent (polycrystalline ceramics) or whether the material contains an organic matrix highly filled with ceramic particles (resin-matrix ceramics). Also presented are the manufacturers' clinical indications for the different materials and an overview of the different fabrication methods and whether they are used as framework materials or monolithic solutions. Current developments in ceramic materials not yet available to the dental market are discussed.

The Use of Resin-based Composite in Children: An Update.

Resin-based composites are an integral component of contemporary pediatric restorative dentistry. They can be utilized effectively for preventive resin restorations, moderate Class II restorations, Class III restorations, Class IV restorations, Class V restorations, and strip crowns. Tooth isolation to prevent contamination is a critical factor, and high-risk children may not be ideal candidates for resin-based composite restorations. Important factors to consider during composite placement are isolation, polymerization shrinkage, and extent of restoration. When utilized correctly, resin-based composites can provide excellent restorations in the primary and permanent dentition. The purpose of this paper was to update previous publications that addressed the use of resin-based composites in children with accepted recommendations through a Pediatric Restorative Dentistry Consensus Conference.

Discrimination of tooth layers and dental restorative materials using cutting sounds.

Dental restoration begins with removing carries and affected tissues with air-turbine rotary cutting handpieces, and later restoring the lost tissues with appropriate restorative materials to retain the functionality. Most restoration materials eventually fail as they age and need to be replaced. One of the difficulties in replacing failing restorations is discerning the boundary of restorative materials, which causes inadvertent removal of healthy tooth layers. Developing an objective and sensor-based method is a promising approach to monitor dental restorative operations and to prevent excessive tooth losses. This paper has analyzed cutting sounds of an air-turbine handpiece to discriminate between tooth layers and two commonly used restorative materials, amalgam and composite. Support vector machines were employed for classification, and the averaged short-time Fourier transform coefficients were selected as the features. The classifier performance was evaluated from different aspects such as the number of features, feature scaling methods, classification schemes, and utilized kernels. The total classification accuracies were 89% and 92% for cases included composite and amalgam materials, respectively. The obtained results indicated the feasibility and effectiveness of the proposed method.

Consideraciones periodontales y protéticas para el tallado de piezas dentarias / Periodontal and prosthetic considerations for teeth grinding

Las preparaciones dentales para prótesis fija, involucran al tejido duro, además la proximidad que existe con la encía hace necesario la comprensión de su estructura y la función del aparato de protección, para que las restauracionesno invadan el ancho biológico constituido por el epitelio de unión y las fibras gingivales; basándonos en los estudios de Gargiulo en 1961, donde la inserción del tejido conjuntivo mide 1.07 mm y la adherencia epitelial 0.97 mm en promedio, sumados al espacio del surco gingival. El biotipo periodontal es de vital importancia para la elección de la altura de terminación del hombro de la preparación, donde el mismo deberá establecerse, previo sondaje óseo a no menos de 2.5 mm de la cresta según Kois (2008). La utilización de materiales y técnicas para la toma de impresiones definitivas deben ser amigables con los tejidos blandos a fin de no producir alteraciones y que las restauraciones sean predecibles, tanto funcional como estéticamente en el transcurso del tiempo

Dental preparations fixed prosthesis, involving the hard tissue, there is also proximity to the gum is necessary to understand the structure and function of the protection device, to restorations without invading the biologic width consisting of the epithelium junction and the gingival fibers; based on Gargiulo studies in 1961, where the insertion of the connective tissue and epithelial measured 1.07 mm 0.97 mm in average adhesion, coupled with sulcular space. The periodontal biotype is of vital importance for the choice of the termination of the shoulder height of the preparation, where it must be established prior tobone sounding no less than 2.5mm crest according Kois (2008). The use of materials and techniques for making final impressions should be friendly soft so as not to alter tissues and restorations predictable, both functionally and aesthetically over time.

Adhesión a tejidos dentarios / Bonding to dental tissues

En las últimas décadas, la odontología restauradora ha logrado un avance significativo que permite preservar tejido dentario mediante la realización de restauraciones adheridas, directas e indirectas. Este enfoque moderno de “Odontología Mínimamente Invasiva”, se centra en obtener preparaciones dentarias con un diseño más conservador, basándose en la eficacia de la adhesión al tejido remanente de los biomateriales utilizados. El conocimiento de las características de los sustratos y de los materiales adhesivos, y la comprensión del mecanismo de adhesión es un factor fundamental para alcanzar el éxito clínico...