A Novel Concept for Developing a Precise and Predictable Post and Core Complex Using the Injectable Resin Technique (Part 2).

Post and core systems have long been used in dentistry for the purposes of replacing missing coronal tooth structure, retaining the core, and providing sufficient retention and resistance form to the final restoration to re-establish original form and function. While Part 1 of this two-part article provided a history of post and core systems and materials and discussed empirical data regarding fiber-reinforced post systems, this second part of the article focuses on an alternative approach for developing a fiber-reinforced post and core system using a monoblock system via the injectable resin technique and a recently developed fiber-optic post. The present article explains the concept of a ferrule effect and demonstrates the novel restorative procedure.

Impact of repeated preheating of bulk-fill resin composite on postoperative hypersensitivity; a randomized controlled clinical trial.

BACKGROUND: This clinical study was conducted aiming to evaluate the impact of repeated preheating of bulk-fill resin composite on postoperative hypersensitivity. METHODS: A total of 105 eligible, consenting adults were recruited. Patients had posterior teeth suffering from proximal decay with no signs of irreversible pulpitis. Patients were prepared for Class II restorations and restored with bulk-fill resin composite. Patients were randomized into three groups of 35 patients according to the number of preheating cycles for the resin composite syringe used; group I: no preheating; control group at room temperature, group II: Resin composite preheated once, and group III: Resin composite preheated ten cycles. Patients were assessed for postoperative dentin hypersensitivity using the visual analogue scale (VAS) at three-time intervals: day one, one week and by the end of one month after restorative treatment. Statistical analysis was performed; ANOVA with a single factor was used to test for significance at a p value ≤ 0.05. For nonparametric data, the Kruskal‒Wallis test was used to compare the three testing groups. Friedman's test was used to study the changes within each group. Dunn's test was used for pairwise comparisons when the Kruskal‒Wallis test or Friedman's test was significant. RESULTS: The scores of the three groups through the three time intervals were almost zero except for the first day where VAS scores were recorded with maximum score of 3 for groups I and II. Groups II and III; there was no statistically significant change in hypersensitivity scores by time with P-values 0.135 and 0.368, respectively. However, for group I there was a significant difference from VAS score recorded on first day and the two following time intervals. CONCLUSION: The repeated preheating cycles of bulk-fill resin composite prior to curing had no adverse effect on the patients regarding postoperative dentin hypersensitivity. This information could be of utmost significance, as the same resin composite syringe can undergo numerous preheating cycles clinically before it is completely consumed with the advantage of improvement on the handling properties. TRIAL REGISTRATION: The protocol of the current study was registered at www. CLINICALTRIALS: gov , with the identification number NCT05289479 on 21/03/2022. All procedures involving human participants were performed in accordance with the ethical standards of the Research Ethics Committee of the Faculty of Dentistry, Minia University, Egypt, under the approval number 73/440 on 11/09/2020.

Clinical evaluation of resorbable polylactic acid (PLA) intracanal posts for primary incisor restoration. Randomized controlled clinical trial.

This randomized, controlled clinical trial compares the clinical performance of glass-fibre and resorbable polylactic acid (PLA) intracanal posts used to restore carious primary incisors in young patients. The study sample includes 180 primary upper central incisors of 90 children aged 3 to 4 years. All patients were randomly divided into two equal groups of 45 children who received PLA and glass-fibre (GFP) intracanal posts. The clinical assessment of incisor restorations was carried out immediately upon completion and at months 3, 6 and 12 according to the following criteria: anatomical form, marginal adaptation, surface roughness, marginal pigmentation, colour match, secondary caries and contact point. The Gingival Index (GI), the Bleeding Index (Cowell modification; mBI), and bite force (BF) were measured. At the 3-month follow-up, the occlusal BF of patients who received PLA posts was higher than the baseline; the GI and mBI scores were lower, by contrast (p < 0.05). This tendency was even more pronounced 6 and 12 months after the restoration. The incidence of side effects or symptoms (apical inflammation, cervical fracture, loosening of the crown) after the PLA posts was significantly lower than after the GFP (p < 0.05). No statistically significant differences were present between the two groups with respect to colour matching, anatomical form, marginal adaptation, marginal pigmentation, surface roughness, occlusal contact and secondary caries. Based on the results, applying PLA intracanal posts and cyanoacrylate to residual anterior crowns in young children can improve their gingival health, reduce side effects, and increase the likelihood of successful restoration.

Two-year evaluation of a nano-hybrid and a bulk-fill resin composite: a randomized, double-blind split-mouth clinical study.

OBJECTIVES: The aim of this study was to compare the 2-year clinical performance of a bulk-fill composite resin and a nano-hybrid-filled composite resin in 6-12-year-old children in a split-mouth design. MATERIALS AND METHODS: This randomized, split-mouth, and double-blind study was conducted on 89 patients aged 6-12 years with caries on bilateral mandibular first molars. In a split-mouth design, restorations of mandibular permanent molars were completed with nano-hybrid organically modified ceramic (ORMOCER)-based bulk-fill composite resin Admira Fusion x-tra (Voco GmbH, Cuxhaven, Germany) and nano-hybrid composite Grandio (Voco, Cuxhaven, Germany). Futurabond U single dose (Voco, Cuxhaven, Germany) was used with selective enamel etching. The clinical success of the restorations was evaluated using USPHS and FDI criteria at 6, 12, and 24-month follow-up controls. RESULTS: In the 2-year follow-up, all restorations were clinically acceptable. Grandio was significantly worse than Admira Fusion x-tra in terms of surface luster and superficial change (p < 0.05). Surface staining and color match scores increased in Admira Fusion x-tra compared with Grandio significantly (p < 0.05). CONCLUSIONS: Although both materials showed acceptable clinical performance over 2 years, a significant difference was observed between the surface luster, surface staining, marginal adaptation, and staining of the nano-hybrid composite placed with the incremental technique and the bulk-fill ORMOCER-based composite resin. CLINICAL RELEVANCE: As an alternative to nano-hybrid composite resins, using bulk-fill restorative materials, which can be indicated in the proper case, may contribute to shortening treatment procedures and increasing patient and physician comfort, leading to clinical success.

Componeer as an aesthetic treatment option for anterior teeth: a case report.

INTRODUCTION: Structural abnormalities or anomalies in the anterior teeth, also known as the aesthetic zone, are an important problem for patients and a challenge for dentists. Structural abnormalities or tooth anomalies can change in color, shape, and function. Most dentists prefer minimally invasive aesthetic treatment. One of the aesthetic treatment options for anterior teeth is veneers. Veneer is a restoration that covers the labial part of the tooth with a thin layer of material to correct abnormalities in the color, shape, or function of the tooth. Veneer restoration can be done indirectly with porcelain material made in a laboratory and directly with composite material on the tooth surface or prefabricated which is available from the factory. Componeer is a prefabricated composite veneer that combines the aesthetic properties of ceramic veneers and the adhesive ability of composite veneers to the tooth structure. This case report describes the treatment of two central incisors that had been filled with composite and peg shapes on both lateral incisors using a componeer. CASE REPORT: A 32-year-old female patient came to the Dental Conservation Clinic at Dentistry Hospital, Padjadjaran University with the main complaint of her right and left upper front teeth and wanted to repair her old fillings and close the gap between her right and left upper front teeth and her canine teeth. Clinical examination showed that teeth 11 and 21 had been filled with composite which had changed color and had an inharmonious shape as well as a gap between the upper front teeth on the right and left sides and the right and left canine teeth. TREATMENT: The maxilla and mandibular teeth are molded for study models and working models. In the working model, a wax-up is carried out, then a mock-up on the patient's teeth. Next, choose the color and size of the components that match the mock up results. Teeth 11 and 21 had their old composite fillings cleaned and refilled with dentin colored composite, teeth 13, 12, 11, 21, 22, and 23 were prepared with a minimum thickness of 0.3 mm to make room for the componeer material. The teeth was etched and bonded, and bonding was applied to the inner surface of the componeer. The composite is placed on the inner surface of the componeer then placed on the labial surface of the tooth and pressed with a special tool, then light cured. The final step is polishing. TREATMENT RESULTS: Teeth 13, 12, 11, 21, 22, and 23 which had undergone veneer treatment using componeer, were controlled after 1 week of treatment. The patient did not complain about the results of the treatment and said he was satisfied with the treatment.

Clinical performance of short fiber reinforced composite and glass hybrid on hypomineralized molars: A 36-month randomized split-mouth study.

OBJECTIVES: This study aimed to assess the clinical performance outcome at 36 months of molars with molar incisor hypomineralization and carious lesions, treated with two different restorative approaches following selective caries removal. METHODS: The children aged 6 to 12 years (18 female, 13 male) included in the study had at least two carious permanent first molars diagnosed with molar incisor hypomineralization. Sixty-two molars were restored in a split-mouth design. In all subjects, selective caries removal was performed so that caries was completely removed from the cavosurface walls and only soft dentin was left above the pulp chamber. Short fiber reinforced composite (SFRC; EverX Flow™) covered by micro-hybrid composite (G-Aenial® posterior composite) and Glass Hybrid (GH; Equia Forte® HT) were used as restorative materials. The restorations were evaluated according to modified United States Public Health Service (USPHS) criteria at baseline, 6, 12, 18, 24, and 36 month follow-ups. RESULTS: During the 36-month follow-up, eight GH and four SFRC restorations failed. The clinical success of both restorations decreased statistically over time (p < 0.001 for both). When variables such as restoration type, sex, age, tooth type, and time were included in the model, the risk of failure of the restorations of the left lower first molar was statistically significantly higher than that of the left upper first molar (p < 0.002). CONCLUSION: Direct composite restorations with SFRC and GH restorations perform similar clinical success with selective caries removal in the management of permanent molars affected by molar incisor hypomineralization. CLINICAL SIGNIFICANCE: SFRC or GH restorations with similar clinical success might be preferred for the management of MIH-affected molars.

A depth-resolved quantitative evaluation method for non-carious cervical lesions treatment with optical coherence tomography.

OBJECTIVES: The aim of this study is prognostic assessment of surface smoothness and the presence of internal bubbles after treatment of non-cancerous cervical lesions (NCCLs) using optical coherence tomography (OCT). METHODS: After treatment with NCCLs, cross-sectional images of the lesion parts of the sample were non-invasively acquired and analyzed. The surface smoothness between tooth and resin, resin and cemento-enamel junction, and the presence bubble inside resin was confirmed. In addition, using an algorithm that distinguishes between resin and dental structure based on OCT cross-sectional images, we quantitatively analyzed the amount of resin used in treating NCCLs and acquired 3D images. RESULTS: The inner structure of the resin in each sample was checked, and the presence of bubbles was confirmed. In addition, the resin sections were separated from the tomographic images acquired by OCT to visualize 3D images. The volume of resin used in the treatment part of each NCCLs samples was quantitatively analyzed as 3.7216 ∼ 14.889 mm3. CONCLUSIONS: OCT is able to measure not only the surface abrasion provided by existing intraoral scanner, but also the size and depth location of interal bubbles, which is distinctive advantage of our method. Based on our results, OCT is a significant tool for qualitative and quantitative analysis of dental NCCLs treatment before and after treatment. CLINICAL SIGNIFICANCE: The study used OCT, a non-destructive diagnostic, to reveal the structure of the resin and the location and size of bubbles after NCCLs treatment. These findings could be golden standard in determining the prognosis of NCCLs treatment.

Clinical performance of preheating thermoviscous composite resin for non-carious cervical lesions restoration: A 24-month randomized clinical trial.

OBJECTIVES: This 24-month, double-blind, split-mouth randomized clinical trial aimed to compare the retention rates of a preheated thermoviscous composite resin (PHT) compared to a non-heated composite resin (NHT) in non-carious cervical lesions (NCCLs). METHODS: A total of 120 restorations were restored on NCCLs using a preheated (VisCalor bulk, Voco GmbH) and a non-heated (Admira Fusion, Voco GmbH) composite resins with 60 restorations per group. A universal adhesive in the selective enamel conditioning was applied. In the PHT group, composite was heated at 68 °C for using a bench heater. In the NHT group, no heating was employed. Both restorative materials were dispensed into caps and inserted into the NCCLs. The restorations were evaluated at baseline, 6, 12, 18, and after 24 months of clinical service using the FDI criteria. Statistical analysis was performed with Kaplan-Meier estimation analysis for retention/fracture rate and Chi-square test for the other FDI parameters (α=0.05). RESULTS: After 24 months 108 restorations were assessed. Seven restorations were lost (two for PHT group and five for NHT group), and the retention rates (95 % confidence interval [CI]) were 96.7 % (81.5-99.9) for PHT group and 90.8 % (81.1-96.0) for NHT group, with no statistical differences between them (p > 0.05). The hazard ratio (95 % CI) was 0.52 (0.27 to 1.01), with no significant difference within groups. In terms of all other FDI parameters that were assessed, all restorations were deemed clinically acceptable. CONCLUSIONS: Both composites showed high rates of retention rates after 24 months. CLINICAL SIGNIFICANCE: The clinical performance of the new preheated thermoviscous was found to be as good as the non-heated composite after 24-month of clinical evaluation in non-carious cervical lesions. REGISTRATION OF CLINICAL TRIALS: RBR-6d6gxxz.

The clinical performance of dental resin composite repeatedly preheated: A randomized controlled clinical trial.

OBJECTIVES: To assess the clinical performance of class II restorations performed by repeatedly preheated resin composite "RC" at 68 °C up to ten times. METHODS: 105 patients were selected and randomized into three groups, each comprising 35 patients. Each patient was provided with a single class II Bulk-fill resin composite "BF-RC" posterior restoration based on the number of preheating cycles; group I (H0): The BF-RC was packed non-heated, group II (H1): BF-RC preheated once, and group III(H10): BF-RC preheated ten cycles. These restorations were evaluated at 1, 3,6, and 12 months, using the modified United States Public Health Service "USPHS". Statistical analysis was performed using Kruskal-Wallis test, Mann Whitney U test, and Friedmann test, where p = 0.05. RESULTS: All the 105 restorations did not suffer from any clinical situation that recommended replacement regarding retention, fracture, secondary caries, or anatomical form. Although all performed restorations did have Alpha and Bravo scores with good clinical performance, the non-preheated RC restorations"" suffered from relatively inferior clinical performance through the follow-up period regarding marginal adaptation, marginal discoloration, and color matching when compared to preheated groups. One and ten times of preheating conducted better clinical performance. CONCLUSIONS: After 12-months follow-up, although no restoration needed replacement or repair in the 3 tested groups, restorations with single and ten times of preheating aided in better clinical performance of RC restorations compared to the non-preheated restorations. Preheating of RC for 10 times could be used safely with good clinical performance of restorations. CLINICAL SIGNIFICANCE: By continually preheating RC syringe up to ten times, the dentist will not only benefit from the enhanced clinical performance and easiness of application but also will use preheated RC syringes without hesitation, relying on the absence of drawbacks related to multiple preheating cycles.

Mechanical and Optical Characterization of Single-shade Resin Composites Used in Posterior Teeth.

OBJECTIVES: This study aimed to evaluate the optical and mechanical performance of two single-shade resin-based composites (RBCs) compared to those of a conventional RBC for restoring posterior teeth. METHODS: Two single-shade RBCs, Omnichroma (Tukoyama) and Vittra Unique APS (FGM), and a conventional RBC, Filtek Z350XT shade A2 (3M Oral Care), were evaluated in this study. The optical shade-matching performance was measured using a spectrophotometer. The light emitted by VALO Grand (Ultradent) and transmitted through the 2.0-mm RBC specimens was evaluated using beam profiling. Knoop hardness (KH, N/mm2), degree of conversion (DC, %) at the top and bottom, flexural strength (FS, MPa), elastic modulus (E, GPa), postgel shrinkage (Shr, %), and shrinkage stress (MPa) were evaluated. Scanning electron microscopy (SEM) was used to characterize the filler. Data for FS, E, and Shr were analyzed by one-way analysis of variance (ANOVA) and KH and DC by repeated one-way ANOVA measurement followed by Tukey test (α=0.05). The modified von Mises stress values, light transmission, and SEM images were analyzed qualitatively. RESULTS: All single-shade RBCs exhibited higher chromatic adaptation than the Filtek Z350XT (p<0.001). Omnichroma exhibited less color difference than Vittra Unique APS, irrespective of the shade. The light transmitted through Omnichroma and Vittra Unique APS increased during polymerization. KH and DC values were significantly reduced from the top to the bottom of the specimens for all RBCs (p<0.001); however, the ratio values were always higher than 80%. In general, all RBCs demonstrated similar mechanical properties. All RBCs exhibited a similar FS (p=0.083) and Shr value (p=0.144). Filtek Z350XT exhibited significantly higher E (p<0.001) than both single-shade RBCs. All RBCs exhibited similar shrinkage stress during restoration and similar residual stress during occlusal loading. CONCLUSIONS: Single-shade Omnichroma and Vittra Unique APS increased light transmission during light-activation, demonstrating better chromatic adaptation than conventional Filtek Z350XT. In general, Omnichroma and Vittra Unique APS exhibited similar mechanical properties and shrinkage stress distributions as Filtek Z350XT during light-activation and occlusal loading.

Polychromatic Restoration of Anterior Fractured Teeth Using a Custom-made Silicone Matrix.

When restoring anterior teeth using resin composites, the use of silicone guide matrices obtained from diagnostic wax-ups is recommended, as this technique facilitates layering and optimizes working time. This is particularly important in polychromatic layering and when more than one anterior tooth is to be restored with resin composites. However, in cases of fractured anterior teeth, it is often not feasible to perform a previous impression and waxing. In these cases, due to trauma and related psychological aspects, patients usually seek immediate esthetic solutions. Therefore, an interesting restorative approach that can simplify the restorative technique is the creation of a silicone guide matrix obtained from the patient's fractured tooth, without the need for prior waxing. This type of personalized matrix was initially proposed by Bertholdo, Ricci, and Barrote. Thus, the purpose of the present work is to demonstrate a modification of the technique for making this type of custom-made matrix for the restoration of two upper central incisors of a 14-year-old patient who fractured his teeth in a bicycle accident.

Longevity of dental restorations in Sjogren's disease patients using electronic dental and health record data.

BACKGROUND: Decreased salivary secretion is not only a risk factor for carious lesions in Sjögren's disease (SD) but also an indicator of deterioration of teeth with every restorative replacement. This study determined the longevity of direct dental restorations placed in patients with SD using matched electronic dental record (EDR) and electronic health record (EHR) data. METHODS: We conducted a retrospective cohort study using EDR and EHR data of Indiana University School of Dentistry patients who have a SD diagnosis in their EHR. Treatment history of patients during 15 years with SD (cases) and their matched controls with at least one direct dental restoration were retrieved from the EDR. Descriptive statistics summarized the study population characteristics. Cox regression models with random effects analyzed differences between cases and controls for time to direct restoration failure. Further the model explored the effect of covariates such as age, sex, race, dental insurance, medical insurance, medical diagnosis, medication use, preventive dental visits per year, and the number of tooth surfaces on time to restoration failure. RESULTS: At least one completed direct restoration was present for 102 cases and 42 controls resulting in a cohort of 144 patients' EDR and EHR data. The cases were distributed as 21 positives, 57 negatives, and 24 uncertain cases based on clinical findings. The average age was 56, about 93% were females, 54% were White, 74% had no dental insurance, 61% had public medical insurance, < 1 preventive dental visit per year, 94% used medications and 93% had a medical diagnosis that potentially causes dry mouth within the overall study cohort. About 529 direct dental restorations were present in cases with SD and 140 restorations in corresponding controls. Hazard ratios of 2.99 (1.48-6.03; p = 0.002) and 3.30 (1.49-7.31, p-value: 0.003) showed significantly decreased time to restoration failure among cases and positive for SD cases compared to controls, respectively. Except for the number of tooth surfaces, no other covariates had a significant influence on the survival time. CONCLUSION: Considering the rapid failure of dental restorations, appropriate post-treatment assessment, management, and evaluation should be implemented while planning restorative dental procedures among cases with SD. Since survival time is decreased with an increase in the number of surfaces, guidelines for restorative procedures should be formulated specifically for patients with SD.

3-year randomized clinical trial to evaluate the performance of posterior composite restorations lined with ion-releasing materials.

To evaluate the impact of using ion-releasing liners on the 3-year clinical performance of posterior resin composite restorations after selective caries excavation with polymer burs. 20 patients were enrolled in this trial. Each patient had two deep carious lesions, one on each side of the mouth. After selective caries removal using polymer bur (PolyBur P1, Komet, Brasseler GmbH Co. KG, Lemgo, Germany), cavities were lined with bioactive ionic resin composite (Activa Bioactive Base/Liner, Pulpdent, Watertown, MA, USA) or resin-modified glass ionomer liner (Riva Light Cure, SDI, Bayswater, Victoria, Australia). All cavities were then restored with nanofilled resin composite (Filtek Z350XT, 3M Oral Care, St. Paul, MN, USA). All the tested materials were placed according to the manufacturers' instructions. Clinical evaluation was accomplished using World Dental Federation (FDI) criteria at baseline and after 6 months, 1, 2, and 3 years. Data were analyzed using Mann-whitney U and Friedman tests (p < 0.05). The success rates were 100% for all resin composite restorations either lined with ion-releasing resin composite or resin-modified glass ionomer liner. Mann-whitney U test revealed that there were no statistically significant differences between both ion-releasing lining material groups for all criteria during the follow-up periods (p > 0.05). Resin composite restorations showed acceptable clinical performance over 3 years either lined with bioactive ionic or resin-modified glass ionomer liners after selective caries excavation preserving pulp vitality. After the 3-year follow-up period, Activa Bioactive and Riva Light Cure liners were clinically effective and they exhibited with the overlying composite restorations successful clinical performance.Trial registration number: NCT05470959. Date of registration: 22/7/2022. Retrospectively registered.

Effect of dry and wet finishing and polishing on color change and opacity of nanofill and nanohybrid composites.

BACKGROUND: As superior esthetic is one of the main reasons for using composite resins, it is very important to be familiar with factors and techniques affecting their optical properties and appearance. AIM: The aim of this study was comparing the effect of finishing and polishing with and without water coolant, on the color change and opacity of composite resin materials. METHODS: Composites used for preparing samples were Z250 (microhybrid), Z350XT (nanofilled), and Z550 (nanohybrid). Then divided into 4 groups of 5 depending on finishing and polishing technique (dry or wet) and time (immediate and after twenty-four hours). After polishing, samples were assessed using a spectrophotometer. Color change and opacity were determined. Data was analyzed using Kolmogorov-Smirnov, ANOVA and Tukey HSD tests. RESULTS: Type of material at both time had a significant effect on ΔE and opacity. Our results in dry and wet technique immediately(T0) showed that the highest and lowest ΔE and opacity belong to Z350XT (p < 0.001). After Twenty-four hours (T24), opacity of Z250 in wet condition was higher than dry condition (p < 0.001). CONCLUSIONS: Wet or dry technique was only effective on color in immediate polishing. Regarding opacity, technique was only effective in case of delayed polishing.

Comparison of saddle contoured metal matrix and pre-contoured self-adhesive matrix in composite resin class II restorations; an in vivo study.

OBJECTIVE: To evaluate composite class II restoration proximal contacts and contours by comparing saddlecontoured metal matrix and pre-contoured self-adhesive matrix system. METHODS: The randomised controlled trial (NCT05414656) was conducted at the Department of Operative Dentistry, School of Dentistry, Shaheed Zulfiqar Ali Bhutto Medical University, Pakistan Institute of Medical Sciences, Islamabad, Pakistan, from May to October 2022, and comprised of patients having supra-gingival class II cavities. They were randomised into class II restoration with saddle-contoured matrix band group A, and restoration with pre-contoured self-adhesive matrix group B. The tightness of proximal contacts was evaluated using the Fédération Dentaire Internationale criteria and the quality of proximal contours was assessed using clinical and radiographic examination. Data was analysed using SPSS 16. RESULTS: Of the 60 subjects, 42(70%) were females and 18(30%) were males. The overall mean age was 38.03±15.33 years. There were 30(50%) subjects in each of the 2 groups. The highest restoration was needed in the upper premolar 20(33.3%). The tightness of proximal contact was not significantly different between the groups (p=0.94). Clinical examination for production of good contours was higher in group A compared to group B, but the difference was not significant (p>0.05). CONCLUSIONS: There was no significant difference between saddle-contoured metal matrix and pre-contoured selfadhesive matrix for composite class II restoration proximal contacts and contours. Clinical Trial Link: https://clinicaltrials.gov RCT (NCT05414656).

Bond strength of prefabricated and CAD-CAM milled glass fiber post-and-cores luted with conventional, universal, and self-adhesive composite resin cement.

STATEMENT OF PROBLEM: Little is known about the effect of different composite resin cements on the bond strength of prefabricated and milled glass fiber post-and-cores. PURPOSE: The purpose of this in vitro study was to compare the push-out bond strengths of root dentin and standard, relined, or computer-aided design and computer-aided manufacturing (CAD-CAM) glass fiber post-and-cores luted with conventional, universal, or self-adhesive composite resin cement. MATERIAL AND METHODS: Post spaces were prepared in 90 premolars. Standard and relined prefabricated and CAD-CAM-milled glass fiber post-and-cores were luted with conventional (RelyX ARC; 3M ESPE), universal (RelyX Ultimate; 3M ESPE), and self-adhesive (RelyX U200; 3M ESPE) composite resin cement (n=10). All specimens were thermally aged (5000 cycles at 5°C and 55°C with a 20-second dwell time) and mechanical fatigue (1 000 000 cycles at 2 Hz, 50-N load). The specimens were sectioned perpendicularly to the root long axis into 1-mm-thick sections (apical, middle, and cervical root thirds), the push-out bond strength was determined, and the mode of failure recorded. Data were submitted to the Kruskal-Wallis test followed by the Bonferroni-Dunn multiple comparison test (α=.05). RESULTS: Push-out bond strength values did not differ (P>.05) among posts at the same root thirds. Standard posts showed higher bond strength than CAD-CAM at the apical third for data grouped by composite resin cements (P<.001). The cervical root thirds had higher bond strength than the apical thirds (P<.05). The cervical, middle, and apical root thirds showed decreasing bond strength values for each type of post for data grouped by composite resin cement (P<.001). Adhesive failures at the dentin-cement interface were predominant. CONCLUSIONS: The type of posts and cements did not affect the bond strength of glass fiber posts. The cervical root thirds had better bonding performance than the apical thirds.

Repair protocols for indirect monolithic restorations: a literature review.

Despite the advancements in indirect monolithic restorations, technical complications may occur during function. To overcome this issues, intraoral repair using resin composite is a practical and low-cost procedure, being able to increase the restoration's longevity. This review aimed to evaluate the need for repair and suggest a standardized repair protocol to the main indirect restorative materials. For this, studies were surveyed from PubMed with no language or date restriction, to investigate the scientific evidence of indirect monolithic restoration repair with direct resin composite. A classification to guide clinical decisions was made based on the FDI World Dental Federation criteria about defective indirect restorations considering esthetic and functional standards, along with the patient's view, to decide when polishing, repairing or replacing a defective restoration. Based on 38 surveyed studies, different resin composite intraoral repair protocols, that included mechanical and chemical aspects, were defined depending on the substrate considering resin-based, glass-ceramic or zirconia restorations. The presented criteria and protocols were developed to guide the clinician's decision-making process regarding defective indirect monolithic restorations, prolonging longevity and increasing clinical success.

Surface Degradation of Ion-releasing Restorative Materials With Cariogenic Challenge.

This study examined the influence of cariogenic environments on the surface roughness of ion-releasing restorative materials (IRMs). Custom-made stainless steel molds with holes of 5 mm × 2mm were used to fabricate 60 disc-shaped specimens of each of the following materials: Activa Bioactive (AV), Beautifil Bulk Restorative (BB), Cention N (Bulk-fill) (CN), and Filtek Z350XT (FZ) (Control). Baseline surface roughness (Ra) measurements were obtained using an optical 3D measurement machine (Alicona Imaging GmbH, Graz, Austria). The specimens were then randomly divided into five subgroups (n=12) and exposed to 10 ml of the following mediums at 37°C: distilled water (DW), demineralization solution (DM), remineralization solution (RM), pH cycling (PC) and air (AR) (control). Ra measurements were again recorded after one week and one month, followed by statistical evaluations with two-way analysis of variance (ANOVA) to determine interactions between materials and mediums. One-way ANOVA and post hoc Games Howell tests were performed for intergroup comparisons at a significance level of 0.05. Mean Ra values ranged from 0.085 ± 0.004 (µm) to 0.198 ± 0.001 µm for the various material-medium combinations. All IRMs showed significant differences in Ra values after exposure to the aqueous mediums. The smoothest surfaces were observed in the AR for all materials. When comparing materials, AV presented the roughest surfaces for all mediums. All IRM materials showed increased surface roughness over time in all cariogenic environments but were below the threshold value for bacterial adhesion, except for AV 1-month post immersion with pH cycling. Therefore, besides AV, the surface roughness of IRMs did not deteriorate to an extent that it is clinically relevant.

A microcomputed tomography analysis of adaptation in premolars with flared root canals restored with different digitally custom fabricated post materials.

STATEMENT OF PROBLEM: Preserving and strengthening the remaining tooth structure of compromised flared root canals after endodontic treatment is challenging. PURPOSE: The purpose of this in vitro study was to compare the adaptation of milled polymer- infiltrated ceramic, fiber-reinforced composite resin, and high-performance semicrystalline thermoplastic resin posts as used to restore mandibular premolars with flared root canals. MATERIAL AND METHODS: Forty sound mandibular premolars were randomly divided into 4 groups: custom Vita Enamic (CV), custom fiber-reinforced composite resin (CF), custom polyetherketoneketone (CP), and prefabricated fiber (RF) posts. After endodontic treatment, each tooth was sectioned 1.5 mm occlusal to the cementoenamel junction. Then, the post space was prepared and flared, except the RF group, to a depth of 9 mm. The post space in RF group was prepared with a post drill. For the CV, CF, and CP groups, the posts were milled, finished, and cemented to their corresponding teeth. Each tooth was scanned using a microcomputed tomography device, and the reconstructed images were analyzed in mesiodistal, buccolingual, and horizontal planes. The cement thickness, cement volume, and volume of voids were measured. The data were analyzed using 3-way ANOVA (cement thickness) and 2-way ANOVA (cement volume and voids volume) tests followed by the post hoc Tukey test (α=.05). RESULTS: The 3-way ANOVA test revealed a significant interaction (P<.001) between material type, section, and surface on the cement thickness. The mean cement thickness in the RF group was significantly higher than in the CV group (P=.001) and CF group (P=.005). The least mean cement thickness was at the apical section followed by the cervical and middle sections. Regarding cement volume, the 2-way ANOVA test showed statistically significant interaction between material type and section. The mean cement volume in the RF group was significantly lower than in the CV group (P=.001), CF group (P=.001), and CP group (P=.001). The highest mean cement volume was in the cervical section followed by the middle and apical sections. The 2-way ANOVA test showed statistically significant interaction (P<.001) between material type and section on the volume of voids. Significant differences were found between the mean volume of voids at the cervical and middle sections (P=.001) and the cervical and apical sections (P=.002). CONCLUSIONS: Compared with prefabricated fiber posts, digitally fabricated polymer-infiltrated ceramic and fiber-reinforced composite resin posts had a thinner cement layer with minimal thickness at the apical section. The digitally fabricated posts had higher cement volume, especially at the cervical section, than prefabricated fiber posts. High volumes of voids were related to the cervical section of all tested posts.

What are the emerging trends in dental composite materials in permanent teeth with occlusal cavities: self-adhesive vs traditional?

DESIGN: The research is a systematic review and meta-analysis of randomized controlled trials (RCTs). AIM: The study aimed to compare the clinical outcomes of self-adhesive flowable composite resins (SAFCs) versus conventional flowable composite resins (FCs) used in occlusal cavity restorations in permanent teeth. METHODS: This research included a search for RCTs. Multiple databases were systematically searched for RCTs with a minimum 1-year follow-up comparing SAFCs to FCs. Outcomes evaluated were retention, secondary caries, marginal adaptation, marginal discoloration, and postoperative sensitivity based on modified USPHS criteria. Risk of bias was assessed using Cochrane RoB 2 tool. Random effects meta-analyses were conducted where applicable. Certainty of evidence was rated using GRADE approach. RESULTS: Five RCTs (four parallel and one split mouth) comprising 138 patients were included. During 1- and 2-year recalls, there were generally no significant differences in clinical performance between SAFCs and FCs. However, FCs applied using the etch-and-rinse technique demonstrated statistically better marginal adaptation at 2 years (3 studies, RR 3.21, 95% CI 1.50-6.83) and marginal discoloration (4 studies, RR 3.40, 95% CI 1.10-10.48). The overall quality of evidence ranged from low to moderate. CONCLUSIONS: SAFCs showed comparable short-term outcomes to FCs in treating occlusal cavities. Further high-quality RCTs with longer follow-up are warranted to confirm long-term performance of SAFCs. Use of separate enamel etching may improve marginal adaptation and discoloration with FCs.