Type Of Restorative Material Research Articles

Comparing the Ability of Various Resin-Based Composites and Techniques to Seal Margins in Class-II Cavities.

Background: Resin-based composites (RBCs) provide excellent esthetics but the marginal micro-leakage in the proximal cavities remains a major concern. The aim of the present study was to assess the ability of various dental RBCs and techniques utilized for sealing deep dentin margin in class-II cavities. Methods: Box-cavities (class-II) on the distal and mesial surfaces of extracted (premolar) teeth were prepared with a gingival margin placed 1mm apical to the cemento-enamel junction. Teeth with prepared class II cavities were randomly divided into four study groups according to the type of restorative materials (conventional RBC; bulk-fill RBC; conventional RBC lined with flowable RBC and conventional RBC lined with resin-modified glass-ionomer-cement (GIC) as open sandwich-technique). Each group was further subdivided into a total-etch subgroup in which a separate etching step was performed before applying the bonding agent and a self-etch subgroup in which a self-etch adhesive system was used (n = 10). For each group, cavities were restored using the respective restorative materials and techniques, subjected to 1000 thermocycles, and placed in the methylene-blue dye. The specimen teeth were sectioned for further microscopic examination for micro-leakage. Results: The least dye penetration values were reported for group 4 (GIC) followed by the group Bulk-fill using the self-etch adhesive system (group 2b). The highest dye penetration was reported for the group Bulk-fill using the total-etch adhesive system (2a), followed by the group conventional RBC using the total-etch adhesive system). The total-etch adhesive system had significantly greater micro-leakage compared to the self-etch adhesive system (1a) (p = 0.026). Conclusions: The self-etch adhesive system significantly reduced the micro-leakage compared to the total-etch system. Bulk-fill RBC when bonded with the self-etch adhesive provided good marginal sealing ability comparable to open sandwich-technique using GIC.

Comparison of the Fracture Resistance and Fracture Mode of Contemporary Restorative Materials to Overcome the Offset of Mandibular Implant-Supported, Cement-Retained Crowns

Background: The purpose was to compare the fracture resistance and the mode of failure of different contemporary restorative materials to restore implant supported, cement-retained mandibular molars. Methods: Two 5 × 10 mm titanium dental implants were mounted in resin blocks and prefabricated titanium and zirconia abutments were connected to each implant. Each implant received forty crowns resembling mandibular first molars. The specimens were divided into four groups (n = 10/group) for each abutment according to the type of material; Group A: porcelain fused to metal crowns; Group B: monolithic zirconia crowns; Group C: zirconia coping with ceramic veneer; Group D: all ceramic lithium disilicate crowns. Specimens were cemented to the abutments, mounted into a universal testing machine, and vertical static load was applied at a speed of 1 mm/min. The test stopped at signs of visual/audible fracture/chipping. Fracture resistance values were analyzed using ANOVA and Tukey’s tests (α ≤ 0.05). The modes of failure were visually observed. Results: A statistically significant difference (p < 0.001) of the fracture resistance values among tested groups was found. The group that showed the highest fracture resistance was Group A for both the titanium and the zirconia abutments (3.029 + 0.248 and 2.59 ± 0.39, respectively) while Group D for both abutments (1.134 + 0.289 and 1.68 ± 0.13) exhibited the least resistance. Conclusions: Fracture resistance and fracture mode varied depending on type of restorative material. For both titanium and zirconia abutments, porcelain fused to metal showed the highest fracture resistance values followed by monolithic zirconia.

Restoration in primary molars placed by undergraduate dental students: reasons for failures

Dental caries is one of the most common chronic childhood diseases and highly prevalent in the world. The commonest treatment procedure for dental caries is a dental restoration which aims to retain the tooth. The survival of restoration depends on the factors associated with restorative materials, patients or operators. Thus, this study aimed to determine the reasons for the failure of restoration in posterior primary teeth performed by undergraduate dental students. A total number of 32 patients aged from 5 to 12 years old were included in this study. Overall, 115 primary molar restorations were assessed clinically using the modified United States Public Health Service Ryge criteria. The O’Leary plaque score was used to evaluate the oral hygiene status of all patients. Then, the data was analysed using the Kaplan-Meier survival curves with log-rank test and Cox regression analysis. 43 (37.4 %) restorations failed with 62.1 % for glass ionomer cement and 36.4 % for composite restorations. Marginal adaptation (62.8 %) is the commonest cause of failure. 76.7% of failure restoration was in patients with poor oral hygiene, and it showed a significant difference compared to patients with moderate and good oral hygiene (p = 0.014). Thus, it was concluded that the type of restorative material and oral hygiene status contributed to the failure of restoration placed in primary molar restorations with failure restoration may occur 2.6 times more in poor oral hygiene patients.

Follow-up of Endodontically Treated Teeth Without Crown Coverage in Vidarbha Region

Statement of Problem: Teeth are weakened after endodontic treatment and should, preferably, be crowned, especially posterior teeth. However, this is not always possible due to certain reasons. Information about the appropriate treatment modalities. This retrospective study was carried out to evaluate the survival of endodontically treated teeth (ETTs) without crown coverage on the basis of various parameters in the region of Vidarbha in Maharashtra, India. Purpose: The aims of this cohort study were to evaluate the survival rate for endodontically treated molars without crown coverage and to identify possible related factors. Materials and Methods: Relevant data from 300 subjects for 148 ETTs was recorded at the Department of Conservative Dentistry and Endodontics, Sharad Pawar Dental College, Wardha, Maharashtra. Follow-up data were derived from a clinical examination and review of the dental record and radiographs. Subjects were not included in the study if teeth had provisional crowns, definitive restorations with cuspal coverage, or with dowel and core and/or crown restorations. The outcome evaluated was defined as a failure if there were negative findings in the condition of a tooth that required a restoration, tooth repair, or extraction. Tooth loss due to endodontic and periodontal reasons was excluded. The independent variables assessed were patient age, gender, location (maxilla or mandible), the existence of an opposing dentition and adjacent teeth, remaining tooth structure, and types of restorative material. One hundred and forty-eight teeth restored using glass-ionomer cement (GIC), SF, and composites were considered successful during the observation time of 3 years because no intervention was needed in these teeth were labeled as “survived.” The teeth restored with composite were 90. The teeth restored with GIC were 14. The teeth restored with silver amalgam were 44. Out of 148 teeth were considered successful during the observation time of 3 years because no intervention was needed in these teeth were labeled as “survived.” Follow-up was done at regular intervals after 5, 7, and 10 years, respectively. At the end of 10 years, the number of teeth survived was 26. The teeth restored with composite were 14. The teeth restored with GIC were 4. The teeth restored with silver amalgam were 8. Results: At the end of the observation time period (10 years), 13 teeth had to be extracted at the end of 6 years and 19 restorations were repaired or replaced at 5, 7, and 9 years. Conclusion: Within the limitations of this study, the amount of remaining tooth structure and types of restorative material have a significant association with the longevity of endodontically treated molars without crown coverage. ETTs evaluated after 10 years showed positive survival and success in long time period. Various parameters were significantly seen to influence the outcome and thereby survival of teeth in the arch when no crowns were placed on ETTs.

A retrospective cross-sectional study of early patient-reported failures of direct restorations placed in a primary dental care setting.

Introduction A retrospective cross-sectional study of early patient-reported failures of restorations was initiated to understand the reasons and factors associated with early failure. Early patient-reported failures are defined as restorations requiring replacement within three months of placement.Aim To investigate if restorative material placed or any other tooth/restoration/patient factors may be associated with early patient-reported failures.Methods In total, 360 restorations were replaced from January 2016 to December 2017. Multivariable analyses (logistic regression model) were used to identify any patient/tooth/restoration factors that were associated with early patient-reported failures.Results Dislodgement, fracture and pain/sensitivity were the three main failure modes. There was significant association between restorative material type and dislodgement and restoration fracture. The odds of dislodgement for composite resin (CR) were 4.3 times higher compared to amalgam. The odds of dislodgement for glass-ionomer cement (GIC) and resin-modified GIC were 3.7 times higher compared to amalgam. The odds of fracture for CR were ten times lower compared to amalgam. The odds of pain for teeth with a history of restoration failure for a particular tooth were five times lower compared to no history of restoration failure for a particular tooth.Conclusions Restorative material type affected patient-reported failures.

Dental amalgam restorations in nationally representative sample of US population aged ≥15 years: NHANES 2011-2016.

ObjectivesEstimate the proportion of amalgam restorations among the US population.MethodsData from ≥15 year old clinically examined dentate participants in three 2‐year survey cycles (NHANES 2011–2016) were analyzed. The 2015–2016 data include restorative material type, allowing for the first time a US estimate of amalgam‐restored teeth.ResultsThe percent of the US population with at least one restoration (65.8 ± 1.4) was relatively constant in 2011–2016. Among those with restored teeth, the mean number of teeth with amalgam restorations increased with age from 4.71 among 15–24 year olds to 7.03 among those ≥75 years. Non‐Hispanic Whites with restored teeth had the highest mean of teeth with amalgam restorations (5.94), while non‐Hispanic Blacks had the lowest (5.08).ConclusionIn 2015–2016, about half (51.5 percent) of restored teeth in the US population contained amalgam. Amalgam presence varied by age, tooth type, and race/ethnicity, but not by sex. These estimates can be used to assess future US caries prevention and dental amalgam reduction efforts.

Influence of material type, thickness and storage on fracture resistance of CAD/CAM occlusal veneers

ObjectivesThe present study aimed to evaluate the effect of restoration thickness, CAD/CAM material, and 6 months of artificial saliva storage on the fracture resistance of occlusal veneers. Materials and methodsA total of 84 intact maxillary molars were sectioned 4.0 mm occlusal to the cementoenamel junction to expose the dentine. The teeth were assigned into 3 main groups according to the type of restorative material (e.max CAD, Vita Enamic, and Lava Ultimate). In each group, the teeth were allocated into 2 subgroups (n = 14) according to restoration thickness (1.0 and 1.5 mm). The veneers were adhesively bonded using dual-cure self-adhesive luting agent. A total of 42 specimens comprising half the tested subgroups were stored in distilled water for 24-h before the test. The remaining half was stored in artificial saliva at 37 ± 1 °C in an incubator for 6 months. All specimens (n = 84) were subjected to 5000 thermal cycles between 5 and 55 °C ± 2 before the fracture resistance test. The maximum force at fracture was recorded in Newton. Failure mode was analyzed using a stereomicroscope. The results were analyzed using a parametric Three-way ANOVA test. ResultsThe results of the Three-way ANOVA test revealed that material type and restoration thickness significantly affected fracture resistance values (p < 0.5), while 6 months of storage in artificial saliva had no significant effect on mean fracture resistance values (p˃0.5). The most common failure patterns in CAD/CAM resin composite and polymer-infiltrated ceramics were scores I and score II. For glass ceramic groups, score IV and III were more dominant. ConclusionsAll the tested CAD/CAM restorations in both thicknesses exhibited fracture resistance values exceeding normal and parafunctional bite forces. Polymer-infiltrated ceramics and CAD/CAM resin composite veneers showed more favorable fracture patterns.

Can the use of surface sealant on restorative materials prevent discoloration related to iron syrup supplements?

The purpose of this study was to evaluate the impact of surface sealants on the stain resistance of restorative materials exposed to iron syrups. Sixty specimens were prepared from each of three restorative materials-compomer (Dyract XP), a microhybrid composite (Filtek Z250), and a nanohybrid composite (G-aenial Anterior). Specimens were divided into three solution groups (n = 20) and immersed in two iron syrups (Ferrum and Ferro Sanol B) and distilled water. Two subgroups, sealed (BisCover ( +)) and unsealed (BisCover (-)), were established for each group (n = 10). Color changes between baseline and measurements at 4, 8, 24, 48, and 72h were calculated with CIEDE2000 (ΔE00) metrics. Data were analyzed with 4-factor mixed-design ANOVA. The first null hypothesis of this study that the use of surface sealant would not mitigate the restorative materials' susceptibility to staining was rejected: significant differences were found between BisCover ( +) and BisCover (-) groups in ΔE00 values for all restorative materials tested in Ferro Sanol B (p < 0.001) and Ferrum (p = 0.002) solutions. The ΔE00 values in the Ferro Sanol B/BisCover ( +) groups were significantly lower than in Ferrum/BisCover ( +) groups (p = 0.002), the second null hypothesis that different forms of iron syrups would not impact the staining resistance of restorative materials was rejected. ΔE00 values were different for each restorative materials tested, the third null hypothesis that the type of restorative material would not affect staining resistance was rejected. The application of surface sealant significantly improved the color stability of restorative materials. The content of iron syrups was also an important factor affecting color change. Nanohybrid composites seem to be more resistant to the staining effects of iron syrups.

In Vitro Effects of Fluoride, Hydroxyapatite, and Bromelain-Containing Toothpaste Types on Surface Roughness of Different Restorative Materials

Aim: To examine the effects of fluoride, hydroxyapatite, and bromelain-containing toothpaste types on the surface roughness of nanohybrid, nanofilled, flowable, and bulk-fill composites; conventional, light-curing, and low-viscosity glass ionomers; and compomers. Materials and Methods: A total of 160 specimens were fabricated using nanohybrid, nanofilled, flowable, and bulk-fill composites; conventional, light-curing, and low-viscosity glass ionomers; and compomers. Each material group was divided into four subgroups ( n = 5) as follows: Control (C), fluoride toothpaste (FT), bromelain toothpaste (BT), and hydroxyapatite toothpaste (HT). Surface roughness values of all specimens were examined using an optical profilometer and a scanning electron microscope at 500, 1,000, and 3,500 magnifications. Results: The highest average roughness value (Ra; µm) was obtained from the conventional glass ionomer material ( P &lt; .001). While the mean Ra value was 0.155±0.116 µm at baseline, it was 0.262±0.203 µm in the fluoride group, 0.237±0.192 µm in the hydroxyapatite group, 0.260±0.293 µm in the bromelain group, and 0.198± 0.187 µm in the control group ( P &lt; .001). Conclusion: We have found that brushing with various types of toothpaste containing fluoride, bromelain, and hydroxyapatite may not result in obtaining different surface roughness values from different types of restorative materials. Differences in surface roughness values of restorative materials may be found at different magnifications under scanning electron microscope.

Evaluation of the radiopacity of restorative materials with different structures and thicknesses using a digital radiography system.

PurposeThe aim of this study was to evaluate the radiopacities of various types of restorative materials with different thicknesses compared with enamel, dentin, and aluminum.Materials and MethodsFour bulk-fill resins, 2 hybrid ceramics, 2 micro-hybrid resin composites, 6 glass ionomer-based materials, 2 zinc phosphate cements, and an amalgam were used in the study. Twelve disk-shaped specimens were prepared from each of 17 restorative materials with thicknesses of 1 mm, 2 mm, and 4 mm (n=4). All the restorative material specimens with the same thickness, an aluminum (Al) step wedge, and enamel and dentin specimens were positioned on a phosphor storage plate and exposed using a dental X-ray unit. The mean gray values were measured on digital images and converted to equivalent Al thicknesses. Statistical analyses were performed using 2-way analysis of variance and the Bonferroni post hoc test (P<0.05).ResultsRadiopacity was significantly affected by both the thickness and the material type (P<0.05). GCP Glass Fill had the lowest radiopacity value for samples of 1 mm thickness, while Vita Enamic had the lowest radiopacity value for 2-mm-thick and 4-mm-thick samples. The materials with the highest radiopacity values after the amalgam were zinc phosphate cements.ConclusionSignificant differences were observed in the radiopacities of restorative materials with different thicknesses. Radiopacity was affected by both the material type and thickness.

Effect of Streptococcus mutans on the flexural strength of resin-based restorative materials

There are a limited number of studies about the effects of microbial aging on the mechanical properties of restorative materials. Therefore, this study aimed to evaluate the effect of simulated aging with Streptococcus mutans on the flexural strength of different resin-based materials. This experimental study was performed on the blocks of different types of restorative materials including composite resin, giomer, and a resin-modified glass ionomer (RMGI). Moreover, three types of aging, such as 30-day storage in distilled water, S. mutans, and germ-free culture medium, were used in this study. The three-point bending flexural strength of the specimens before and after aging was measured according to the International Organization for Standardization-4049 standard. Data were analyzed by two-way ANOVA and post hoc Tukey's tests. A P < 0.05 was considered statistically significant. Results showed that the 30-day aging with the S. mutans significantly reduced the flexural strength of all three types of materials (P = 0.00). In all restorative materials, storage in a bacteria-free culture medium acted the same as distilled water, and there was no significant difference between these two solutions in terms of the flexural strength of the material, compared to the before-aging strength (P > 0.05). Furthermore, no significant difference was observed between S. mutans-based aging and distilled water aging regarding RMGI (P = 0.75). It can be concluded that aging by S. mutans reduced the flexural strength in all three restorative materials.

Comparison of the microleakage between two different flowable composite resin restorations with 8th generation bond system in Class II cavity: An in vitro stereomicroscopic study.

Introduction Marginal adaptability of composite resins is one of the prime factors for the success of class II cavity restoration. Materials and Methodology: Forty non-carious extracted mandibular molar with fully formed apices were collected and Class II box type cavities were prepared on both mesial and distal surfaces of every tooth using a new straight fissure diamond bur and high-speed airrotor handpiece. According to the type of restorative materials used, teeth were divided into Group I (n=20): Restored with SDR (Smart Dentin Replacement) and Group II (n=20): Restored with Tetric Eva Flow Bulk Fill. After 24 hours of storage in distilled water at 37˚C, the restored specimens were subjected to artificial aging by thermocycling. The teeth were then immersed in a 2% methylene blue dye for 24 hours. All samples were cut longitudinally through the center of the restorations with the help of an isomet diamond saw. The sections were then observed under a stereomicroscope at 25X for scoring the depth of dye penetration at cervical and axial walls toward the pulp. Results: Mean score of Group Ia is 0.4±0.83 and Ib was 0.55±0.88 respectively while the mean score of Group IIa was 0.75±1.118 and in IIb was 0.75±1.019 respectively. Microleakage was found to be highest in Group IIa and minimum in Group Ia. Conclusion: Use of a flowable composite SDR above and below the CEJ in Class II composite resin restorations showed good results.

MINIMALLY INVASIVE TREATMENT OF CARIOUS LESIONS IN PEDIATRIC DENTISTRY

Dificuldades no atendimento odontológico das crianças, devido à necessidade de controle do comportamento e de suporte familiar adequado, além de peculiaridades relativas à anatomia dos dentes decíduos, suscitam o uso de técnicas de mínima intervenção para o controle da cárie dentária. Logo, o objetivo do presente trabalho foi realizar uma revisão bibliográfica sobre o tratamento minimamente invasivo de lesões de cárie em dentes decíduos, abordando as características, indicações e limitações de diferentes técnicas dentro desse conceito. O controle de biofilme sem selamento dentário é uma abordagem na qual nenhum tipo de material restaurador é colocado para selar as cavidades, sendo instituída a higiene bucal de modo eficiente como estratégia para paralisar as lesões de cárie. O selamento da lesão sem remoção de tecido cariado prevê a utilização de selantes resinosos ou coroas metálicas diretamente sobre as cavidades, sem remoção prévia de tecido cariado. Já a remoção seletiva de cárie seguida de restauração é a técnica mais aceita e utilizada em odontopediatria, sendo atualmente considerado o padrão ouro, em detrimento da remoção total de tecido cariado. Apesar de a mínima intervenção ser bem aceita pelas crianças, sua aceitabilidade pelos responsáveis e odontopediatras ainda é questionável. Verificou-se que todas essas técnicas se apresentam como alternativas eficazes para o tratamento minimamente invasivo em odontopediatria. Entretanto, é fundamental o entendimento, participação e comprometimento dos familiares, tendo em vista que o controle do biofilme e da dieta possuem papel fundamental para garantir o sucesso desses tratamentos.

Effect of Bleaching with 15% Carbamide Peroxide on Flexural Strength of Three Resin-Based Restorative Materials.

Objectives:Considering the increasing use of vital bleaching procedures and the increased application of newly introduced resin-based materials for tooth restoration, this study was designed to evaluate the effect of 15% carbamide peroxide gel on the flexural strength of three resin-based restorative materials.Materials and Methods:Three different types of restorative materials namely Beautifil II giomer, Cention N, and Z250 micro-hybrid composite resin were evaluated in this in vitro, experimental study. Twenty-four bar-shaped specimens were prepared from each restorative material, totaling 72 specimens, and were randomly assigned to two subgroups with and without bleaching procedure (n=12). In the bleaching subgroups, 15% carbamide peroxide gel was applied on the specimen surface 8 h a day for 14 days. The flexural strength of the specimens was then measured. Two-way ANOVA was used to compare the flexural strength of the specimens.Results:There was a significant reduction in the flexural strength of materials following exposure to the bleaching agent (P<0.05). The flexural strength was significantly higher in the groups that did not undergo bleaching. However, the mean flexural strength of the restorative materials was not significantly different (P=0.12).Conclusion:The flexural strength of Beautifil II giomer, Cention N, and Z250 micro-hybrid composite resin could be compromised subsequent to bleaching with 15% carbamide peroxide gel. The three resin-based restorative materials exhibited similar flexural strength values irrespective of the use or no use of 15% carbamide peroxide gel.

Current status and research trends of lithium disilicate in dentistry: A bibliometric analysis

Statement of problemLithium disilicate (LD) is a popular dental ceramic and has been a focus of dental research. Nevertheless, a quantified literature analysis focusing on the research of lithium disilicate is lacking. PurposeThe purpose of this bibliometric analysis was to review the progress of research into lithium disilicate in dentistry, including the identification of contributing researchers, organizations, countries or regions, journals, and the analysis of high-impact keywords and research trending. Material and methodsThe search was carried out within the topic field of the Web of Science (WoS) database, collecting publications related to LD from between 1996 and 2019. Metadata including the titles, abstracts, keywords, authors, affiliations, countries or regions, and references were extracted. Bibliometric indicators in terms of documents, authors, journals, and keywords were analyzed. ResultsBetween 1996 and 2019, the dental research on LD trended upward. Scholars in the United States, Germany, Switzerland, and Brazil actively participated in the research on LD, and publications from the United States had the most citations. The Journal of Prosthetic Dentistry and Dental Materials were the major contributing journals. High-impact terms could be categorized into types of restorative material, types of prostheses, and properties or techniques of materials. Co-occurrence and relative normalized citation analysis of keywords highlighted several research interests, such as comparison studies between LD and zirconia, computer-aided design and computer-aided manufacturing (CAD-CAM) techniques, and the performance of complete coverage LD restorations. ConclusionsWith the global upsurge in research on lithium disilicate, extensive collaborations and citations have been noted among authors, institutions, and countries or regions. Research hotspots include types of restorative material, types of prostheses, and properties or techniques of materials.

Evaluation of shade correspondence between current monolithic CAD/CAM blocks and target shade tab by considering the influence of cement shade and restorative material thickness.

It was aimed to evaluate shade matching between novel CAD/CAM blocks and the A2 target shade tab by considering the influence of cement shade and restorative material thickness on the chromatic background. A total number of 120 rectangular-shaped specimens were subtracted from four different prefabricated CAD/CAM blocks [Vita Enamic (VE), Lava Ultimate (LU), GC Cerasmart (GC), and Vita Mark II (VMII)]. These specimens had thicknesses of 0.5mm and 1.0mm. Three different shades (A2, opaque, and translucent) of dual-polymerized resin cement were chosen. The dentin shade (A3.5) restorative composite foundation was incrementally fabricated in a silicon mold. For control group, the A2 shade tab of the Vitapan classical shade guide was used. Different restorative material-cement-foundation assemblies were generated with optic gel. Color readings were performed by using a clinical spectrophotometer, and CIEDE2000 (ΔE00) formula was used to assess color differences. Data were statistically analyzed (α = 0.05). With increasing thickness, color difference values decreased. Higher mean ΔE00 units were observed in all restorative material sub-groups for 0.5mm thickness. In TR shade, no statistically significant difference was detected among the mean ΔE00 values of 0.5mm-thick restorative materials. Color differences in groups 1.0mm-opaque-LU and 1.0mm-opaque-GC indicated perceptible but clinically acceptable values (0.8˂ΔE00 ≤ 1.8). The highest and lowest ΔE00 units were observed in the 0.5mm-A2-VE group (ΔE00 = 7.07) and 1mm-opaque-GC group (ΔE00 = 1.46), respectively. Luting cement shade, restorative material type, and thickness significantly influenced the resultant color of restoration. Opaque cement on dentin foundation exhibited lower color differences.

Effect of home and over the contour bleaching on stainability of CAD/CAM esthetic restorative materials

To determine the effect of home and over the counter bleaching on the stainability of CAD/CAM restorative materials, and to correlate the surface roughness with discoloration. Specimens were fabricated from feldspathic ceramic, an hybrid ceramic, a resin nano-ceramic, and lithium disilicate-reinforced glass ceramic. After baseline surface roughness (Ra1) and color measurement, each material was randomly divided into three groups according to bleaching regimen as Opalescence PF and; Opalescence Go; control. Then, the second color and surface roughness (Ra2) measurements were made. Thereafter, all specimens were immersed in a coffee solution for 12 days and the third color measurement was made. Color and whiteness change (CIELAB- ΔEab , CIEDE2000-ΔE00 , whiteness index-ΔWID ) were calculated after bleaching (ΔE1;ΔE00 1;ΔWID 1) and immersion in the coffee solution (ΔE2;ΔE00 2;ΔWID 2). According to both CIELAB, CIEDE 2000 and WID formulas, the highest mean ΔE1, ΔE2, ΔWID 1, ΔWID 2 values were observed for LAVA Ultimate groups while the lowest values were measured for e.max CAD groups. The findings also showed that there was a positively significant relationship between Ra2, and ΔE2 and ΔWID 2. Type of restorative materials and bleaching agents had an impact on color change after bleaching and immersion in coffee. Home and over-the-counter bleaching agents may cause an increase in susceptibility of restorative materials to staining.

Effect of immediate dentin sealing, bonding technique, and restorative material on the bond strength of indirect restorations

Objective: The objective of this study was to evaluate the effect of immediate dentin sealing, bonding technique, and restorative material on the dentin bond strength of an indirect composite (Solidex) and a resin nanoceramic CAD/CAM block (LAVA Ultimate). Material and Methods: A total of 120 periodontally extracted human molar teeth were abraded horizontally and divided into two groups according to dentin sealing procedures (delayed dentin sealing [DDS] and immediate dentin sealing [IDS]). Next, all teeth were attached to a simulated pulpal pressure mechanism. The specimens were removed from the mechanism after a week. Teeth were subdivided into three groups based on the bonding technique and the type of cement used (Acid-etching + Single Bond Universal + RelyX Ultimate, Single Bond Universal + RelyX Ultimate, RelyX Unicem). Each subgroup was further divided into 2 subgroups according to the type of restorative material used (Solidex [n=10], Lava Ultimate CAD/CAM restorative material [n=10]).. Sixty cylindrical samples prepared using both the restorative materials were bonded to the tooth surface according to their group’s bonding procedures. All specimens were embedded in chemically cured acrylic resin for shear bond strength test. The shear bond strength (SBS) of the specimens was determined by a universal testing machine with a headspeed of 0.5 mm/min. Results: Three-way ANOVA, independent-sample t test and post hoc Tukey comparison tests (?=0.05) were performed on all data. There were significant differences between the groups. It was found that IDS process significantly increased bond strength in all groups. When dentin bond strengths of tested luting cements were compared, the highest bond strength values were recorded in groups in which the specimens were luted with RelyX Ultimate cement using etch-and-rinse technique. The lowest bond strength values were obtained from groups that used RelyX Unicem as the luting cement. Conclusions: IDS improves bond strength of indirect restorations. Moreover, bonding techniques may have critical effects on the dentin bond strength of indirect restorative materials. The cements’ specific affinity levels to both restorative materials and dentin could be considered as the reason of the situation.KEYWORDSIDS; Luting cement; Shear bond strength; Resin nanoceramic; CAD/CAM.

Marginal integrity of aesthetic restorations following intracoronal bleaching with sweet potato extract as an additive: An SEM study

The aim of this in vitro study was to evaluate the marginal integrity of an alkasite restoration in comparison to that of a conventional composite resin restoration following intra-coronal bleaching with 30% hydrogen peroxide (HP) containing sweet potato extract (SPE) as an additive. Access cavities were prepared in 60 extracted human incisors. The teeth were decoronated 2mm below the CEJ and the pulp chambers were sealed cervically. The samples were divided into two groups (n = 30) based on the type of restorative material - group I: Hybrid composite resin and group II: Alkasite restorative material. Both the groups were divided into three subgroups (n = 10) based on the intra-coronal bleaching agent used namely, subgroup A: no bleaching (NB); subgroup B: 30% hydrogen peroxide (HP) and subgroup C: 30% hydrogen peroxide containing SPE (HSP). The tooth-restorative interface was observed under a scanning electron microscope (SEM) to determine the marginal integrity. The results were tabulated and statistically analyzed using one-way ANOVA. Specimens bleached with HP alone showed higher marginal gaps, irrespective of the restorative material used. Subgroups A and C showed lesser marginal gaps under both the restorative materials. An improved marginal integrity was seen with the alkasite material. It can be concluded that the addition of SPE to HP improves the marginal integrity of the coronal restorative material placed immediately post-bleaching. The new alkasite material holds promise as a permanent coronal seal in cases of intra-coronal bleaching.

Effect of an Optical Whitening Toothpaste on Color Stability of Tooth-Colored Restorative Materials.

Objectives This study aimed to assess the effect of an optical whitening toothpaste on color stability of microhybrid, nanofilled, and microfilled composite resins and resin-modified glass ionomer (RMGI) cement in comparison of two other toothpastes. Materials and Methods In this experimental study, disc-shaped composite samples were fabricated. The samples were then polished using silicon carbide papers. Twenty-seven samples of each material were fabricated and subjected to colorimetry using a spectrophotometer. Each group of material was then divided into three subgroups for the application of conventional whitening and whitening containing blue covarine toothpastes. One operator brushed the samples with an electric soft toothbrush with circular motion twice a day, each time for 30 seconds. Colorimetry was performed at 0, 1, 7, 30, and 90 days. Statistical Analysis Two-way analysis of variance (ANOVA), one-way ANOVA, and Tukey’s honestly significant difference (HSD) test were used for statistical analysis. Results The interaction effect of type of restorative material and time on ∆E was not significant at baseline or 1 day ( p > 0.05). The effect of type of toothpaste on ∆E was not significant at baseline or 1 day ( p = 0.78) but the effect of type of material was significant ( p < 0.05). The toothpastes had significantly different effects on ∆E of Z250 at all time points ( p < 0.05) except for ∆E0–30 ( p = 0.106). The toothpastes had significantly different effects on ∆E of Z350 and Gradia at all time points ( p < 0.05). The same was true for RMGI except for ∆E0–7 ( p = 0.43) and ∆E0–90 ( p = 0.52). The majority of color changes caused by toothpastes were not clinically perceivable (∆E < 3.3), except for ∆E0–90 by the whitening toothpaste (∆E = 9), ∆E0–90 by the conventional toothpaste for Z350 (∆E = 3.9), and ∆E0–1 by the whitening toothpaste for RMGI (∆E = 3.7). Conclusion The color change of all composite samples was not clinically perceivable (<3.3) at all time points, which shows that the tested toothpastes do not cause a significant change in color of composite materials.