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Purpose: To examine and compare stress values of implants, highest tensile and compressive values, and their distribution in cortical and trabecular bone near and around the implant region using different materials (aramid fiber, glass fiber, polyethylene fiber, carbon fiber, and cobalt-chromium [Co-Cr] alloy). Four dental implants were placed in the maxillary crest with two different location scenarios, and the 3D finite element analysis method was used to evaluate stress characteristics. Materials and Methods: Two maxillary models were created in which the implants were placed in different locations (lateral and first premolar, canine and second premolar). Four implant-supported overdenture prostheses were reinforced, applying Co-Cr alloy, glass fiber, aramid fiber, and carbon fiber. Static loads of 200 N were applied on the first molar region using the food stuff method. Stresses around the implants and denture-bearing areas and compression and tensile stresses on the cortical and trabecular bone were evaluated. Results: In all tested models, the highest von Mises stresses on implants and prostheses were observed in aramid fiber--reinforced overdentures. This was followed by glass fiber, Co-Cr alloy, and carbon fiber groups, respectively. It was observed that the lowest tensile and highest compression stress values in cortical and trabecular bone occurred in prostheses supported with carbon fiber. In all infrastructure materials, the design in which the implants were placed bilaterally in the lateral teeth and the first premolar region was found to be advantageous in terms of stress levels and distribution. Conclusion: High elastic modulus fiber--reinforced overdenture prostheses transmitted less stress to implants and surrounding tissues than Co-Cr alloy. Anteriorly placed implant design illustrated lower stress values in the prosthesis, implant, and cortical and trabecular bone, and this placement design may increase the survival rates of both dental implants and overdentures. In light of this study, fibers can be recommended for clinical use and securely applied as an alternative material to metal support. [ABSTRACT FROM AUTHOR]

This study compares the fracture strength of teeth restored with conventional round fiber post (CP) and bundle post (BP) in two different lengths. A total of 48 mandibular premolars were selected. Endodontic treatment was performed, and the premolars were divided into four groups (n = 12 per group): Group C9 = 9-mm CP; Group C5 = 5-mm CP; Group B9 = 9-mm BP; Group B5 = 5-mm BP. Post spaces were prepared, and posts were disinfected with alcohol. Silane was applied, and posts were placed with self-etch dual-cure adhesive. The core structures were created using dual-cure adhesive and standardized core-matrix. Specimens were embedded in acrylic, and the periodontal ligament was simulated with polyvinyl-siloxane impression material. Thermocycling was performed, and specimens were then loaded at a 45-degree angle to the long axis. The failure mode was analyzed with x5 magnification, and statistical analyses were performed. No statistical difference was found between post systems and post lengths (P > .05). Chi-square test revealed no statistical difference in the failure mode (P > .05). BP did not affect fracture resistance compared to CP. For the restoration of extremely irregular canals with a fiber post, BP can be used as an alternative system because it does not reduce the fracture strength. If necessary, longer posts can be used without decreasing the fracture resistance. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the 15-year survival rate of zirconia (Y-TZP) implants with a roughened acid-etched surface in a retrospective post-market clinical follow-up (PMCF) study. Materials and Methods: One-piece ceramic implants (CeraRoot) with a roughened acid-etched surface (ICE) were used. Six different implant shapes/sizes were used in this study. Either a standard or flapless surgical approach was used for implant placement. Simultaneous bone augmentation or sinus elevation was performed when bone height or width was deficient. Definitive zirconia restorations were placed after 2 months or later if the Periotest value was > -3. The implants were followed up for up to 15 years. Results: A total of 1,828 implants were placed in 771 patients with a mean age of 51.18 years. The overall implant survival rate after 15 years of follow-up was 98.69%. Conclusion: From this long-term investigation, it can be concluded that CeraRoot ceramic implants showed a 15-year long-term clinical performance with a survival rate of 98.69% under the described protocol, without significant differences between the six implant shapes/sizes. [ABSTRACT FROM AUTHOR]

Purpose: To compare the biomechanical behaviors of different surgical options that are preferred for implant-supported fixed prosthetic rehabilitation of the atrophic edentulous maxilla. Materials and Methods: A 3D finite element analysis (FEA) model was generated from the computed tomography data of a patient with an atrophic edentulous maxilla. Four scenarios were created in the atrophic maxilla. In model 1, the maxilla was reconstructed with an onlay bone graft harvested from the anterior iliac crest, and sinus augmentation procedures were performed. Standard dental implants were placed in the lateral incisor, first premolar, and first molar regions on each side. In model 2, the anterior part of the atrophic maxilla was reconstructed with an onlay bone graft harvested from the mandibular ramus, and zygomatic implants were placed in the posterior part of the maxilla. In models 3 and 4, two-piece subperiosteal implants made of titanium and polyether ether ketone (PEEK) materials, respectively, were placed in the atrophic maxilla. All implants were loaded with 150-N and 50-N forces in vertical and lateral directions, respectively. Stress accumulation on bones, implants, abutments, and prosthetic frameworks was investigated. Results: The tensile stress in both cortical and trabecular bone was highest in the iliac bone grafting group under vertical loading. The compressive stress in both cortical and trabecular bone was the highest in the PEEK subperiosteal implant model, and the compressive stress value on the trabecular bone exceeded the strength of the trabecular bone. The highest von Mises stress in the implants was obtained in the iliac bone grafting group under vertical loading. The highest stress value in the abutments was detected for the titanium subperiosteal implant. The highest von Mises stress in the prosthetic framework was detected in the titanium subperiosteal implant group, under both vertical and lateral loading. Conclusion: Based on the stress accumulation results of the four different scenarios, it can be seen that there is no ideal treatment modality for the fixed implant-supported prosthetic rehabilitation of the atrophic edentulous maxilla. Various intraoperative and prosthetic modifications are suggested to decrease the risk of biomechanical complications during long-term follow-up. [ABSTRACT FROM AUTHOR]

Purpose: To assess the radiographic and histomorphometric outcomes of horizontally augmented maxillary alveolar ridges using solid nonperforated customized titanium barriers. Materials and Methods: This case series study included patients who received guided bone regeneration treatment in the anterior maxillary esthetic zone (eight patients, 18 dental implants) using patient-specific solid titanium barriers loaded with a mix of autogenous and xenogenic particulate bone grafts. A radiographic comparison between three time periods (immediately postoperative, 4 months, and 10 months) included software-aided calibration of the linear changes in the horizontal dimensions on CBCT cross-sectional cuts after being standardized. Bone core specimens were retrieved for histomorphometric analysis by the time of implant insertion. Results: Wound healing was uneventful, except for two patients who showed soft tissue breakdown that did not affect the outcome. There was a statistically significant difference between the mean horizontal bone change at the different time intervals (P < .001), with a 79.6% ± 29.2% mean area of newly formed bone. Conclusion: GBR using customized solid titanium barriers appears to be efficient and promising concerning the final horizontal bone gain and the quality of the augmented sites. [ABSTRACT FROM AUTHOR]

Maintaining facial soft tissue contour and inter-implant papilla are challenging for implants in the esthetic zone. To counteract the inevitable hard and soft tissue changes after tooth extraction, the socket shield technique (SST) has been advocated as means to maintain the facial and/ or interproximal osseous and gingival architecture. Because SST is a technique-sensitive procedure, various complications related to SST have been reported. This article presents a unique complication after a socket shield procedure and a novel management of the complication. [ABSTRACT FROM AUTHOR]

Lesion formation after soft tissue gingival grafting is a rare but challenging clinical scenario to manage. This report presents a unique case of cyst formation after connective tissue grafting. All previously reported cases are confined to the mandibular labial lateral-canine space, whereas the present case is the first found in the maxilla. These cysts manifest clinically 9 months to 1.5 years after grafting and may communicate with the surface, as evidenced by sinus tract or cystic discharge. Because of the unique nature of these lesions with respect to clinical history, appearance, symptoms, and location, the differential diagnosis should be limited. The treatment recommendation is complete surgical excision, which should eliminate the risk of recurrence. In this report, a novel case is presented, and the literature is reviewed to discuss etiology and provide treatment recommendatio [ABSTRACT FROM AUTHOR]

Abstract Dental materials are challenged by wear processes in the oral environment and should be evaluated in laboratory tests prior to clinical use. Many laboratory wear-testing devices are high-cost investments and not available for cross-centre comparisons. The ‘Rub&Roll’ wear machine enables controlled application of force, chemical and mechanical loading, but the initial design was not able to test against rigid antagonist materials. The current study aimed to probe the sensitivity of a new ‘Rub&Roll’ set-up by evaluating the effect of force and test solution parameters (deionized water; water + abrasive medium; acid + abrasive medium) on the wear behaviour of direct and indirect dental resin-based composites (RBCs) compared with human molars against 3D-printed rod antagonists. Molars exhibited greater height loss than RBCs in all test groups, with the largest differences recorded with acidic solutions. Direct RBCs showed significantly greater wear than indirect RBCs in the groups containing abrasive media. The acidic + abrasive medium did not result in increased wear of RBC materials. The developed method using the ‘Rub&Roll’ wear machine in the current investigation has provided a sensitive wear test method to allow initial screening of resin-based composite materials compared with extracted human molars under the influence of different mechanical and erosive challenges.

Introduction: Soft-Liner is an acrylic temporary relining material for the temporary rebasing (relining) of acrylic dentures and tissue conditioning. The use of soft liner as a medium to deliver anti-bacterial and anti-inflammatory medications locally to the site enhances the healing of the soft tissues, further maintaining the mucosa healthy in the transitional healing period. Soft liners modified with Triple Antibiotic Paste (TAP) help in soft tissue healing and reduce post-surgical inflammation. Aim: To evaluate the anti-bacterial, anti-inflammatory efficacy, and cytotoxicity of TAP modified soft liners with conventional soft liners. Materials and Methods: The in-vitro study was conducted in the Gold Laboratory at Saveetha Dental College, Chennai, Tamil Nadu, India, in March 2023. A solution of TAP was prepared and mixed with Gas Chromatography (GC) soft liner material. The antibacterial efficacy against the strains of Staphylococcus aureus, Pseudomonas, and E. faecalis was assessed, and Mueller Hinton Agar was used to identify the zone of inhibition. The Kolmogorov-Smirnov test was conducted to assess the normality of the distribution, and non-parametric tests were performed for further analysis. A chi-square test was used to compare the cytotoxicity of TAP modified soft liners, which was assessed by a Lethality assay for brine shrimps over 24 hours. The Egg albumin denaturation assay was used to assess anti-inflammatory properties, with different concentrations of 10 μL, 20 μL, 30 μL, 40 μL, and 50 μL. Human Gingival Fibroblast (HGF) was used for the cell line study, and the isolation of HGF was performed by enzymatic digestion subjected to collagenase (900 u/mL) and dispase (400 u/mL) digestion at 37°C for one hour. Results: In comparing the modified TAP liners to commercially available liners on the basis of antibacterial efficacy, there was increased anti-bacterial efficacy in the TAP modified liners, which increased with increasing concentration, with the maximum being 40.25±14.87 mm for a 1:3 concentration against S. aureus and the least being 23±1.3 mm of unmodified soft liners against Pseudomonas and S. aureus. Different concentrations of 10 μL, 20 μL, 30 μL, 40 μL were used for the anti-inflammatory test, and as the concentration increased, anti-inflammatory activity also increased. The cytotoxicity of the material increased from 10% to 40% as the concentration of TAP rose from 5 μL to 80 μL. Conclusion: TAP shows a better response in managing postoperative inflammation and better soft tissue healing when incorporated into the soft liners. More precise studies are needed to understand the exact mechanism of TAP.

Background: Comparative studies of interim veneer restorations crafted using subtractive computer-aided manufacturing (s-CAM) milling technology and traditional direct hand-made approaches are needed. Purpose: This comparative in vitro study evaluated the fracture resistance of two types of provisional veneer restorations for maxillary central incisors: milled (s-CAM) and traditional direct hand-made bis-acryl veneers. Materials and methods: Fifty maxillary right central incisor veneers (25 specimens per group) were fabricated and divided according to the fabrication method: (1) s-CAM milled (Structure CAD, VOCO Dental); and (2) hand-made (Protemp Plus, 3M). The restorations were cemented onto 3D-printed resin dies using temporary cement and subjected to 1000 cycles of thermal cycling between 5° and 55 °C. These restorations subsequently were subjected to compressive loading until fracture occurred. Images of the fractured samples were captured using a scanning electron microscope (SEM). Statistical analysis was performed using the one-way ANOVA test and the Mann-Whitney U test. Results: Significant differences (p

This study explores the effect of using dental brushes with or without metacrylate-based modeling resins on long-term color stability and surface topographies of resin-based composites. This study examined the effects of two variables: (1) the type of brush used (Art brush, Micro-brush, or Mylar strip) and (2) the application of a modeling resin (applied or not applied). The specimens were artificially aged through 10,000 cycles of thermocycling and subsequently immersed in coffee for 30 days. Measurements of color and surface roughness were taken at baseline and after the aging, using a non-contact profilometer for surface roughness and a spectrophotometer for color. Data were analyzed using paired t-tests and one-way ANOVA. Resin-based composites smoothed with dental brushes or micro brushes without modeling resins exhibited lower color change (ΔE) than other groups. Paired t-tests revealed significant differences in average surface roughness (Ra) and valley depth (Rv) for each surfacing technique before and after aging (p ⩽ 0.01). The root means square average of the profile heights (Rq) significantly increased in the control and micro-brush groups (p ⩽ 0.01). In conclusion, the use of brushes in resin-based composites placement does not increase the susceptibility to staining. Instead, the inclusion of resin modeling contributes to discoloration over time. [ABSTRACT FROM AUTHOR]

Background: Matrix metalloproteinases (MMPs) are critical enzymes involved in the remodeling and defense mechanisms of dental pulp tissue. While their role in permanent teeth has been extensively studied, research focusing on MMPs in primary teeth remains limited. This gap highlights the need for further investigations to understand the specific contributions of MMPs to pulpal defense in primary teeth. Moreover, the clinical efficacy of Biodentine as a pulpotomy material in primary teeth warrants further exploration through well-designed studies to establish its success and long-term outcomes in pediatric dentistry. Aim: This study aims to compare the expression levels of MMP-2, MMP-8, and MMP-9 in cases of reversible and irreversible pulpitis. Additionally, it seeks to evaluate the clinical success of Mineral Trioxide Aggregate (MTA) and Biodentine when used as pulpotomy agents in primary molars. By analyzing the differential expression of these MMPs, the study will contribute to a better understanding of their role in pulpal inflammation and the potential therapeutic outcomes of MTA and Biodentine in primary molars. Design: In this parallel randomized controlled trial, 63 mandibular primary second molars were assigned to two main groups: Group 1, consisting of 42 teeth diagnosed with reversible pulpitis, and Group 2, consisting of 21 teeth diagnosed with irreversible pulpitis. Group 1 was further divided into two randomized subgroups, each containing 21 teeth. The expression levels of MMP-2, MMP-8, and MMP-9 were evaluated in all samples. Pulpotomy treatments were performed using MTA and Biodentine in Group 1. Clinical and radiographic evaluations were conducted over an 18-month follow-up period. Statistical analyses were carried out using The Kolmogorov-Smirnov test, t-test and Fisher's exact test (p < 0.05). Results: The study revealed that MMP-2 and MMP-9 expression levels were significantly elevated in specimens with irreversible pulpitis (p = 0.01), indicating a potential correlation between these matrix metalloproteinases and the severity of pulpal inflammation. However, no significant difference was observed in the clinical success rates of pulpotomies performed with MTA and Biodentine, suggesting that both materials are equally effective in the treatment of primary molars with reversible pulpitis. Conclusions: The expression of MMP-2 and MMP-9 in pulpal blood presents a promising biomarker for assessing the degree of pulpal inflammation in primary teeth, offering a potentially valuable diagnostic tool. Additionally, the clinical success of Biodentine in pulpotomy procedures supports its viability as an effective alternative to MTA, providing a reliable option. Clinical Trial Registration ID: The study protocol has been registered with an ID: NCT05145686. Registration Date: 9th November 2021. [ABSTRACT FROM AUTHOR]

Background: Calcium silicate-based bioceramics have been applied in endodontics as advantageous materials for years, many chemical components and new synthesizing methods were used to improve the base formulation of the materials for positively affecting the sealers properties. Recently, a novel biomaterial formulation, grounded in strontium silicate, has been introduced to the market, offering potential advancements in the field. Objective: To comparatively analyze the cytotoxicity and cell migration effects of a novel strontium silicate-based bioceramic material (CRoot SP) and those of calcium silicate-based (iRoot SP) and epoxide amine resin (AH Plus) sealers on stem cells derived from rat apical papilla(rSCAPs). Methods: rSCAPs were isolated and characterized in vitro and subsequently cultured in the presence of various concentrations of CRoot SP, iRoot SP and AH Plus extracts. Cytotoxicity was assessed by CCK-8 assay, and cell-migration capacity was assessed by using wound healing assays. Results: No significant differences in cell viability were observed in the 0.02 mg/mL and 0.2 mg/mL sealer groups. The cell viability of CRoot SP was consistently greater than that of iRoot SP at concentrations of 5 mg/mL and 10 mg/mL across all time points. Maximum cytotoxic effect was noted on day 5 with 10 mg/mL AH Plus.The scratch was partly healed by cell migration in all groups at 24 h, and the 0.02 mg/mL, and 0.2 mg/mL CRoot SP exerted beneficial effects on rSCAPs migration. Conclusions: CRoot SP exhibited less cytotoxic than the iRoot SP and AH Plus extracts after setting. A lower concentration of CRoot SP thus promotes the cell migration capacity of rSCAPs, and it may achieve better tissue repair during root canal treatment. [ABSTRACT FROM AUTHOR]

This study investigates the potential of incorporating akermanite and hardystonite nanoparticles (NPs) into commercially available zinc phosphate cement. Akermanite and hardystonite NPs were synthesized through a mechanical route and characterized using X‐ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The NPs were then added to the cement at a concentration of 5 wt%, and the physical and biological properties of the resulting composite were evaluated. The results showed that the incorporation of NPs led to a significant reduction in porosity (from 12.4% to 5.6%) and a notable improvement in compressive strength (from 90 to 120 MPa) compared to the control group. MTT assay revealed that the cement containing NPs exhibited no significant toxicity and even promoted cell growth and proliferation. Specifically, cell viability increased by 15%, and cell proliferation rate increased by 20% compared to the control group. These findings suggest that the designed cement has suitable mechanical and biological properties, making it a promising material for dental and orthopedic applications. [ABSTRACT FROM AUTHOR]

Backgrounds: This study aimed to compare the effects of different energy drinks on the surface roughness, weight loss, and color change of various bioactive restorative materials. Methods: Charisma Diamond One, Activa™ BioActive Restorative, Activa™ Presto™ and Equia Forte HT Fil samples were prepared using plastic molds (8 × 2 mm) (n = 10/groups). After polishing, the samples were weighed, their colors were recorded using a spectrophotometer according to the CIEDE2000 system, and their surface roughness was measured using a profilometer. The samples were immersed in Powerade, Burn, Monster and distilled water for 7 days. After immersion, all the measurements were repeated. Statistical analyses were performed using the Wilcoxon signed-rank test and the Mann‒Whitney U test (p < 0.05). Results: All energy drinks roughened the surface of Equia Forte HT Fil (p < 0.05). Powerade and Monster increased the Ra of all materials after 7 days (p < 0.05). Burns affected all materials except the Activa Bioactive (p < 0.05). Significant weight loss was observed in the Equia Forte group after immersion in all the energy drinks, whereas no weight loss was observed in the other groups. According to the color measurements, ΔE00 values were greater in the Burn and Monster groups, except for the Equia Forte HT Fil group (p < 0.05). Conclusion: Energy drinks affected bioactive materials to varying degrees. The glass hybrid material was the most affected, and the bioactive restorative materials based on the resin matrix were the least. [ABSTRACT FROM AUTHOR]

Objective Clinical Considerations Conclusions Clinical Significance This article aims to demonstrate the clinical application of a comprehensive workflow that integrates digital tools for accurate color matching, and its immediate implementation in the restoration of anterior teeth.Two patients demonstrating dissatisfaction regarding a maxillary central incisor had an old restoration replaced resorting to a digital workflow to enhance the predictability of the new direct restoration. OptiShade allowed the precise assessment of tooth color and the CompoShade application provided precise color and material selection, as well as the determination of a layering strategy. Precision and accuracy of the colorimeter and the composite layering application were demonstrated clinically in vivo.Implementing a digital workflow with the integration of OptiShade measurements and the CompoShade layering recipe calculation, as well as the respective realistic try‐in, enables the achievement of precise color matching for anterior composite restorations.The employment of a digital colorimeter and layering recipes simplify shade matching, and optimizes composite resin clinical use and success. The implementation of a realistic try‐in, previous to the definitive restoration, allows the clinician to perform any adjustments if needed. [ABSTRACT FROM AUTHOR]

Background: Digitally fabricated dentures may require relining due to continual alveolar ridge resorption. However, studies evaluating the tensile bond strength (TBS) of digitally fabricated dentures bonded to denture liners are lacking. This study aimed to evaluate the TBS of autopolymerized, heat-polymerized, milled, and 3D printed denture base materials bonded to 2 acrylic-based and 2 silicone-based denture liners, both before and after thermocycling. Additionally, the impact of thermocycling on the TBS were also evaluated. Methods: The TBS of 4 different denture base materials (Palapress (PL), Vertex Rapid Simplified (VR), Smile CAM total prosthesis (SC), and NextDent denture 3D+ (ND)) bonded to 2 acrylic-based (GC Soft-Liner (GC) and Tokuyama Rebase II (RB)) and 2 silicone-based (Ufi Gel P (UP) and Sofreliner Tough M (ST)) denture liners were tested. Specimens (n = 8) were divided into non-thermocycling and thermocycling groups. Non-thermocycling specimens were tested after 24-hours water immersion, while thermocycling specimens were underwent 5000 cycle and were immediately tested. Mode of failure was examined under a stereomicroscope. Data were analyzed using 2-way ANOVA and Tukey HSD tests (α = 0.05), and independent samples t test (α = 0.05) for TBS between non-thermocycling and thermocycling groups. Results: For the non-thermocycling groups, within the same denture liner material, no significant differences were found between denture base materials, except the ND + RB group, which had significantly lower TBS. For the thermocycling groups, within the same denture liner material, the TBS in the PL group exhibited the highest and the ND group exhibited the lowest. Within the same denture base material, in both non-thermocycling and thermocycling groups, the TBS in the ST group exhibited the highest; in contrast, that in the GC group exhibited the lowest. No significant differences were observed in TBS between non-thermocycling and thermocycling groups, except for denture base materials bonded to the ST group, SC + UP, and ND + UP groups. Conclusions: Milled denture base can be relined with acrylic-based or silicone-based denture liner. However, cautions should be exercised when relining 3D printed denture base. Thermocycling did not affect TBS between acrylic-based denture liners and denture bases. In contrast, it affected the bond between silicone-based denture liner and denture base. [ABSTRACT FROM AUTHOR]

Background: The screw-in effect is a tendency of a nickel-titanium (NiTi) rotary endodontic file to be pulled into the canal, which can result in a sudden increase in stress leading to instrument fracture, and over-instrumentation beyond the apex. To reduce screw-in force, repeated up-and-down movements are recommended to distribute flexural stress during instrumentation, especially in curved and constricted canals. However, there is no consensus on the optimal number of repetitions. Therefore, this study aimed to examine how repeated up-and-down movements at the working length affect torque/force generation, surface defects, and canal shaping ability of JIZAI and TruNatomy instruments. Methods: An original automated root canal instrumentation device was used to prepare canals and to record torque/force changes. The mesial roots of human mandibular molars with approximately 30˚ of canal curvature were selected through geometric matching using micro-computed tomography. The samples were divided into three groups according to the number of up-and-down movements at the working length (1, 3, and 6 times; n = 24 each) and subdivided according to the instruments: JIZAI (#13/0.04 taper, #25/0.04 taper, and #35/0.04 taper) or TruNatomy (#17/0.02 taper, #26/0.04 taper, and #36/0.03 tape) (n = 12 each). The design, surface defects, phase transformation temperatures, nickel-titanium ratios, torque, force, shaping ability, and surface deformation were evaluated. Data were analyzed with the Kruskal-Wallis and Dunn's tests (α = 0.05). Results: The instruments had different designs and phase transformation temperatures. The 3 and 6 up-and-down movements resulted in a smaller upward force compared to 1 movement (p < 0.05). TruNatomy generated significantly less maximum torque, force, and surface wear than JIZAI (p < 0.05). However, TruNatomy exhibited a larger canal deviation (p < 0.05). No statistical differences in shaping ability were detected between different up-and-down movements. Conclusions: Under laboratory conditions with JIZAI and TruNatomy, a single up-and-down movement at the working length increased the screw-in force of subsequent instruments in severely curved canals in the single-length instrumentation technique. A single up-and-down movement generated more surface defects on the file when using JIZAI. TruNatomy resulted in less stress generation during instrumentation, while JIZAI better maintained the curvature of root canals. [ABSTRACT FROM AUTHOR]

Background: Effects of the aging process on the flexural strength of Y-TZP and different Y-PSZ ceramics of different thicknesses were investigated. Methods: 300 disc-shaped samples (12 mm diameter, 0.8 and 1.5 mm thicknesses) were made from 5 different zirconia materials 3Y-TZP LA, 4Y-PSZ, 5Y-PSZ, 3 + 5Y-PSZ and 4 + 5Y-PSZ. Experimental groups were artificially aged in an autoclave at 134 °C, 2 bar pressure for 1 and 5 h; control groups were not subjected to any treatment. Microstructural analysis was conducted using Scanning Electron Microscopy, and X-Ray Diffraction analysis determined the crystalline phase content. The impact of aging on flexural strength was investigated with the use of the biaxial flexural strength test. Data were analyzed using three-way ANOVA tests with a significance level of p < 0.05, applying Bonferroni correction for multiple comparisons. Results: Statistically significant differences in flexural strength were observed among the materials and the material thicknesses (p < 0.05), while there were no significant differences among the aging times (p > 0.05). The highest mean flexural strength values were recorded in the case of the 3 Y-TZP-1.5 mm–5 h group (744.1 ± 61.2 MPa), which was attributed to phase-transformation toughening. The lowest values were observed in the case of the 5 Y-PSZ-1.5 mm–5 h (338.3 ± 34.8 MPa) group. Conclusions: Both material type and thickness significantly affect the flexural strength of zirconia ceramics, whereas aging time does not; thus, material selection and thickness are crucial considerations for clinicians. [ABSTRACT FROM AUTHOR]

Background: The existence of voids within the mineral trioxide aggregate (MTA) composition is one of the factors that can influence the treatment outcome. The primary objective of this study was to quantitatively assess and compare the MTA orthograde obturation quality in severe curved root canals using two different MTA compaction techniques: manual compaction with K-file, or Auger technique using micro-computed tomography (micro-CT) imaging. Methods: For this study, 26 mandibular first molar teeth with severely curved mesiobuccal root canals were selected. These samples were randomly divided into two groups. All root canals were instrumented using ProTaper Gold rotary files up to the F3 file at the working length. In one group, OrthoMTA was compacted using a stainless steel K-file, while in the other group, the Auger technique was employed for compaction into the root canals. Once the MTA had completely set, the filled root canals were subjected to scanning using a high-resolution micro-CT scanner. The porosity volume was determined as a percentage in relation to the overal volume of the canal, and the collected data were subjected to analysis using SPSS software, with the significance level set at P < 0.05. Results: The two techniques had no significant difference in open, closed, and total mean porosity. In both groups, the mean of open porosity was significantly more than closed porosity. Conclusions: According to the results of the present study, neither of these two techniques is preferred to the other, and factors such as working time, etc., can be considered to choose the more appropriate clinical technique. [ABSTRACT FROM AUTHOR]

Objective: Oral healthcare professionals encounter considerable challenges while providing services to curb the oral disease burden. The aim of this study was to explore the challenges faced by oral health practitioners providing oral health services in Nyarugenge, Rwanda and to appraise the availability and adequacy of oral hygiene equipment, instruments, and materials. Methods: This was a cross-sectional concurrent mixed methods study. The quantitative and qualitative parts were independent during data collection and analyses and merged during the interpretation phase. All seven public health facilities and 14 dental professionals working in Nyarugenge were included in the study. Data were collected using an audit checklist and an in-depth interview guide. Descriptive statistics were used to analyze the quantitative data. The interviews were analyzed using thematic content analysis. Results: Most of the dental health professionals were dental therapists (n = 11), women (n = 9), aged 31–40 years (n = 7), and with 11–20 years' experience as oral health practitioners (n = 6). There were five health centers and two hospitals that were audited for equipment, instruments, and materials. The audit of the facilities revealed that most facilities have dental equipment and instruments, but none have adequate preventive dental instruments and materials. Four broad themes emerged from the interviews with the oral health practitioners, namely human resources, supply chain management, patients' oral health awareness and service rendering, and strategic management and administration. The most significant challenges oral health practitioners faced included high dental practitioner/patient ratios, lack of adequate and appropriate equipment and materials, patients' lack of oral health awareness, and a lack of administrative support. Conclusions: Well-established community preventive interventions, such as a mobile oral health App, could reduce the patient/provider ratio by increasing population awareness of oral health and encouraging healthy behaviours. The management of the health facilities should address the human resource challenges and equipment supply chain issues. [ABSTRACT FROM AUTHOR]

The aim was to evaluate the influence of repair resin type on repair bond strength in the direct resin restorations through a systematic review. Electronic databases MEDLINE via PubMed, Web of Science, Scopus, BBO, and LILACS were searched, and the reference lists of relevant studies were further hand-searched. A total of 15,709 articles that were browsed yielding to a final of five studies were included in meta-analysis. Analyses were performed using R software with the 'metafor' package, with standardized mean differences employed. A multi-level meta-analysis was conducted utilizing restricted maximum-likelihood estimates (p ≤.05). In the shear bond strength group, significant heterogeneity was observed (Q = 50.274, p <.0001), whereas no significant heterogeneity was detected in the microtensile bond strength group (Q = 5.102, p =.4063). Separate analyses of both shear bond strength and microtensile bond strength groups showed no statistically significant differences between dissimilar and similar materials (p >.05). Egger's regression indicated no evidence of publication bias in either group. Sensitivity analyses revealed statistically insignificant pooled effect sizes for shear bond strength. In the microtensile group, one study influenced the results when excluded from the analysis. It could be suggested that the repair of composite resin with the same kind of resin composite is not mandatory. [ABSTRACT FROM AUTHOR]

The utilization of two‐component systems comprising camphorquinone (CQ) and aromatic amines has become prevalent in the photopolymerization. However, there are still concerns about the safety of this CQ/amine system, mainly because of the toxicity associated with the leaching of aromatic amines. In light of these concerns, this study aims to develop novel coinitiator combinations featuring CQ and amines which cannot be leached out of materials, enabling free radical polymerization of representative dentalmethacrylate resins under blue light irradiation. This approach involves the initial design and analysis of hydrogen donors with low C─H bond dissociation energy through molecular modeling. Subsequently, copolymerizable methacrylate functional groups are incorporated via chemical modification, allowing it to act as both coinitiator and copolymerization monomer to achieve low migrationand leachability properties. This work presents, for the first time, the synthesis of the innovative coinitiator and compares its performance with the benchmark CQ/ethyl‐4‐dimethylaminobenzoate (EDB)‐based photoinitiation system (PIS). The results demonstrate the effectiveness of the newly proposed PIS. Finally, an in‐depth investigation is conducted into the reaction mechanism associated with this PIS through molecular orbital calculations and electron spin resonance studies. [ABSTRACT FROM AUTHOR]

This study evaluated the effect of stearyl methacrylate addition on the physical and mechanical properties of bisphenol A glycidyl methacrylate- and triethylene glycol dimethacrylate-based polymers, which are traditionally used in dental applications. Methacrylate-based monomer compositions are polymerized under the visible blue light spectrum. An analysis of double bond conversion, surface microhardness test, three-point bending test and water sorption and water solubility were tested to determine the physical and mechanical properties of the dental polymers. The results indicated that stearyl methacrylate addition up to 25 wt% reduced the water sorption of the polymers. At amounts of stearyl methacrylate higher than 25 wt%, the solubility of the polymer in water increases due to the monofunctional structure. Mechanical properties are negatively affected by the increasing stearyl methacrylate ratio. Further, the addition of stearyl methacrylate slightly increased thermal stability. As such, the amount of stearyl methacrylate in a polymer composition is critical for the optimization of its mechanical and physical properties. According to the results, the amount of stearyl methacrylate has to be between 12.5–25 wt%. [ABSTRACT FROM AUTHOR]

The introduction of 3D printing technology in dentistry has opened new treatment options. The ongoing development of different materials for these printing purposes has recently enabled the production of definitive indirect restorations via 3D printing. To identify relevant data, a systematic search was conducted in three databases, namely PubMed, Scopus, and Web of Science. Additionally, a manual search using individual search terms was performed. Only English, peer-reviewed articles that encompassed in vitro or in vivo research on the mechanical properties of 3D-printed composite materials were included, provided they met the predefined inclusion and exclusion criteria. After screening 1142 research articles, 14 primary studies were selected. The included studies mainly utilized digital light processing (DLP) technology, less commonly stereolithography (SLA), and once PolyJet printing technology. The material properties of various composite resins, such as VarseoSmile Crown Plus (VSC) and Crowntec (CT), were studied, including Vickers hardness, flexural strength, elastic modulus, compressive strength, tensile strength, fracture resistance, and wear. The studies aimed to compare the behavior of the tested additive composites to each other, conventional composites, and subtractive-manufactured materials. This scoping review examined the mechanical properties of composites used for 3D printing of definitive restorations. The aim was to provide a comprehensive overview of the current knowledge on this topic and identify any gaps for future research. The findings suggest that 3D-printed composites are not yet the first option for indirect restorations, due to their insufficient mechanical properties. Due to limited evidence, more research is needed in this area. Specifically, there is a need for clinical trials and long-term in vivo research. [ABSTRACT FROM AUTHOR]

Filler content in dental composites is credited for affecting its physical and mechanical properties. This study evaluated the correlation between the filler percentage and strength, modulus, shrinkage stress, depth of cure, translucency and radiopacity of commercially available high- and low-viscosity dental composites. Filler weight percentage (wt%) was determined through the burned ash technique (800 °C for 15 min). Three-point bend flexural strength and modulus were measured according to ISO 4049 with 2 mm × 2 mm × 25 mm bars. Shrinkage stress was evaluated using a universal testing machine in which composite was polymerized through two transparent acrylic rods 2 mm apart. Shrinkage was measured from the maximum force following 500 s. The translucency parameter (TP) was measured as the difference in color (ΔE00) of 1 mm thick specimens against white and black tiles. The depth of cure was measured according to ISO 4049 in a cylindrical metal mold (4 mm diameter) with a 10 s cure. Radiopacity was measured by taking a digital X-ray (70 kVp for 0.32 s at 400 mm distance) of 1 mm thick specimens and comparing the radiopacity to an aluminum step wedge using image analysis software. The correlation between the filler wt% and properties was measured by Pearson's correlation coefficient using SPSS. There was a positive linear correlation between the filler wt% and modulus (r = 0.78, p < 0.01), flexural strength (r = 0.46, p < 0.01) and radiopacity (r = 0.36, p < 0.01) and negative correlation with translucency (r = −0.29, p < 0.01). Filler wt% best predicts the modulus and strength and, to a lesser extent, the radiopacity and translucency. All but two of the high- and low-viscosity composites from the same manufacturer had statistically equivalent strengths as each other; however, the high-viscosity materials almost always had a statistically higher modulus. For two of the flowable composites measured from the same manufacturer (3M and Dentsply), there was a lower shrinkage stress in the bulk-fill version of the material but not for the other two manufacturers (Ivoclar and Tokuyama). All flowable bulk-fill composites achieved a deeper depth of cure than the flowable composite from the same manufacturer other than Omnichroma Flow Bulk. [ABSTRACT FROM AUTHOR]

Photopolymerization is becoming increasingly popular in industry due to its copious advantages. The vital factor in the entire pre-polymerization formulation is the presence of photoinitiators. Depending on the application, photoinitiators have different features. Hence, scientists are particularly interested in developing new photoinitiators that can expand the scope of applications and be used to create products with the features demanded by current trends. This brief review summarizes the photoinitiators used in dental materials and hydrogels and those obtained from natural and synthetic sources. [ABSTRACT FROM AUTHOR]

Color stability is crucial for dental materials to ensure they perfectly match a patient's tooth color. This is particularly challenging in photoresist-based additive manufacturing. Although some studies have addressed this issue, the exact causes of discoloration and ways to minimize it remain unclear. In this study, the intrinsic causes of discoloration in materials intended for 3D printing are investigated by examining thin-film samples (1200 µm) of various compositions, which are stored under different conditions. The samples are evaluated by measuring the UV-Vis absorption spectra at regular intervals to monitor changes. The findings reveal that both the composition of the formulations and the storage conditions significantly influence the discoloration behavior. Furthermore, methods have been developed to reduce or completely prevent discoloration. The use of photoinitiators with sterically demanding benzoyl moieties, as well as the addition of stabilizers, effectively decreases the intensity of emerging discoloration. Furthermore, incorporating the oxidizing agent cumene hydroperoxide (CHP) results in materials that maintain color stability. [ABSTRACT FROM AUTHOR]

MXene is a novel two-dimensional layered nanomaterial with a very large specific surface area and abundant surface functional groups, endowing it with unique physical and chemical properties. MXene can be compounded with other functional materials to significantly improve the performance of MXene composites or broaden their application scope. Meanwhile, with the development of flexible composite preparation technology, it has promoted the continuous expansion of its application fields. The introduction and combination of different materials can improve the performance of flexible composites and make them have a broader application prospect. In recent years, researchers have started preparing MXene materials as flexible composites for applications such as supercapacitors, sensors, electromagnetic shielding and thermal management. This paper gives a brief introduction to flexible composites and MXene materials, reviews the applications of MXene based flexible composites in various fields as well as the research progress, and provides an outlook on their future development direction. [ABSTRACT FROM AUTHOR]

Objectives: We aimed to evaluate ceramic-alloy interface and emphasize the alteration of alloy microstructure after ceramic layering. Materials and Methods: Thirty-two discs made from a ceramic-alloy combination of pre-sintered cobalt-chromium (CoCr), cast CoCr, cast nickelchromium (NiCr), or pre-sintered zirconia were prepared with eight discs in each group. Four specimens were examined as manufactured and four were ceramic-layered. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-Ray diffractometer (XRD), and an atomic force microscope were used for analysis. Non-layered specimens received ceramic fire-heating without adding any ceramic. Alloy microstructure was compared before and after ceramic veneering or heating within the same group. Mean differences in grain size and surface roughness were compared among groups. P<0.05 was considered significant. Results: SEM showed a close bonding interface between alloys and ceramics. EDX demonstrated differences compared to the manufacturer's composition. Ceramic-layering reduced grain size for both milled alloys (P<0.05), whereas grain size increased in cast groups (P=0.011). Heat treatment did the same for the CoCr groups (P=0.013). Ceramic veneering increased the surface roughness of the cast CoCr (Gi) (P=0.029) and NiCr (Wi) (P=0.005) groups, whereas zirconia roughness average (Ra) showed a slight decrease (P=0.282). XRD showed no differences among zirconia, NiCr, and milled CoCr groups before and after veneering. Crystallite size differed between monoclinic and tetragonal phases in zirconia. Conclusion: The study highlights that ceramic-layering induces significant microstructural changes in alloys, enhancing bonding potential and mechanical stability. Pre-sintered materials show a fine homogeneous surface, optimizing ceramic adherence and potentially improving clinical outcomes. [ABSTRACT FROM AUTHOR]

Featured Application: Few or no finishing systems are specifically available for 3D printable materials for permanent dental restorations. The generic systems tested in this study were generally able to give clinically acceptable results for roughness. Conversely, the outcome was poor for gloss, except for curing in a nitrogen chamber unit. The results suggest the need to develop finishing/polishing systems dedicated to this specific category of prosthetic materials. The object of the study was to assess the effect of different finishing and polishing systems on the roughness and gloss of a 3D-printed permanent restorative material. One 3D printable Permanent material was selected for the study. Squared-shaped specimens (14 mm2; 5 mm thickness) were obtained by designing and printing. Eighty specimens were produced and randomly assigned (n = 10) to 8 finishing and polishing methods: Sof-Lex™ Spiral Wheels (SW), Sof-Lex™ XT Pop-on Disc (SD), Identoflex Lucent no paste (Ln), Identoflex Lucent + paste (Lp), Resin Nitrogen polymerized (NG), Optiglaze (OG), Opti1Step (OS), and HiLusterPLUS (HL). Surface roughness and gloss were then measured by a roughness meter and a glossmeter, respectively. For roughness, statistically significant differences were found (p < 0.001), with NG(a) > SD(b) = OG(b) = Lp(b); Lp(b) = Ln(bc); Ln(bc) = OS(cd); OS(cd) = SW(de); and SW(de) = HL(e). For gloss, statistically significant differences were also identified (p < 0.001) with NG(a) > SD(b) > Lp(c) = OS(c) = OG(cd); OG(cd) = Ln(d) > HL(e) = SW(e). The nitrogen chamber polymerization showed better results for both roughness and gloss. Multi-step finishing/polishing systems were able to produce smoother surfaces than 1-step and 2-step systems. [ABSTRACT FROM AUTHOR]

Featured Application: Our research is the second step toward both establishing a standard aging protocol as well as selecting methods useful for evaluating the degradation of dental materials. The durability and performance of dental composites are essential for ensuring long-lasting dental restorations. However, there is a lack of a standardized procedure for evaluating the lifespan of dental materials. Our proposal assumed that dental materials should be tested under aggressive aging conditions to accelerate materials' degradation in vitro and such an approach should simulate prolonged material usage in the oral cavity. A comprehensive examination of the impacts of three aging methodologies on various mechanical properties, including the flexural strength (FS), diametral tensile strength (DTS), hardness (HV), fracture toughness (FT), flexural fatigue limit (FFL), and microstructure of selected dental materials (Resin F, Flow-Art and Arkon), was conducted. The findings revealed that preformed aging results in an average reduction of 30% in the mechanical strength properties of the dental composites when compared to the control. Notably, a strong correlation was identified between FS and FFL post-aging whereas no such relationship was observed between these parameters and FT. This paper highlights the significance of aging tests for new dental composites and recommends a focus on flexural strength and fracture toughness to optimize costs and time efficiency. Furthermore, the establishment of a standardized test for fracture toughness in dental composites is recommended. It is proposed that a minimum flexural strength of more than 32–48 MPa after aging should be maintained. A more extensive analysis of commercially available materials is suggested to refine the proper evaluation methods for composite materials. [ABSTRACT FROM AUTHOR]

Background: To evaluate the accuracy of the electronic apex locators (EALs), and Cone-Beam Computed Tomography (CBCT) scanning, both in working length (WL) determination and in the detection of root canal perforations in retreatment cases. Methods: Sixty human mandibular premolars were selected. After crown removal partially and canal access, root canals were instrumented and irrigated. The obturation process utilized gutta-percha and sealer with warm vertical compaction. Two groups were distinguished: one without perforation (Group 1) and the other with an apical third perforation (Group 2). Retreatment included filling removal, apical preparation, and irrigation. Actual working lengths (AWL) were determined using a stereomicroscope. CBCT images were used to measure CBCT working length (CWL), with adjustments for optimal views. Propex II and Dentaport ZX were used to measure electronic working length (EWL). Differences between EWL and AWL, as well as CWL, were analyzed to gauge accuracy. Data underwent Two-way ANOVA analysis. Measurements within ± 0.5 and ± 1 mm tolerance ranges were deemed successful for each device, followed by applying the Pearson Chi-square test. Results: The study reveals no significant inter-group variations in device performance (p >.05). Dentaport ZX missed detecting perforation in two Group 2 (apical perforation) cases. For ± 1 mm tolerance, Propex II displayed the highest success in Group 2 (apical perforation). Conclusion: This study demonstrates the comparable performance of Propex II, Dentaport ZX, and CBCT in endodontic retreatment, providing insights into diagnostic reliability. [ABSTRACT FROM AUTHOR]

Photocuring 3D printing of materials exhibiting high fracture toughness and excellent mechanical properties (flexural strength/modulus) is challenging. Nowadays, most of the photocurable 3D printing resins are based on a mixture of multifunctional (meth)acrylates and provide therefore brittle materials. This article describes further developments of a toughening strategy based on the incorporation of block copolymers in low crosslink density methacrylate‐based materials. Six dimethacrylates bearing a bisphenol A core and urethane groups are successfully synthesized. Various spacers between the bisphenol A core and the methacrylate groups are selected. Each monomer is combined with (octahydro‐4,7‐methano‐1H‐indenyl)methyl acrylate as a monofunctional monomer and a poly(ε‐caprolactone)‐polydimethylsiloxane‐poly(ε‐caprolactone) triblock copolymer is added as toughener. It is shown that the addition of the triblock copolymer results for all mixtures in a strong increase of the fracture toughness. Moreover, the higher the amount of monofunctional monomer, the stronger the increase. The nature of the urethane dimethacrylate is found to have a significant influence on the fracture toughness, flexural strength, and flexural modulus of cured materials. Two of the synthesized dimethacrylates are identified as promising candidates for the development of fracture‐tough photocuring 3D printing materials. [ABSTRACT FROM AUTHOR]

Background: To evaluate the flexural strength of digitally milled and printed denture base materials. Methods: The materials tested were Lucitone 199 denture base disc (Dentsply Sirona), AvaDent denture base puck (AvaDent), KeyMill denture base disc (Keystone), Lucitone digital print denture base resin (Dentsply Sirona), Formlab denture base resin (Formlabs), and Dentca base resin II (Dentca). Sixty bar-shaped specimens of each material were prepared for flexural strength testing and were divided into five groups: control, thermocycled, fatigue cycled, and repair using two different materials. The flexural strength and modulus were tested using a 3-point bend test performed on an Instron Universal Testing Machine with a 1kN load cell. The specimens were centered under a loading apparatus with a perpendicular alignment. The loading rate was a crosshead speed of 0.5 mm/min. Each specimen was loaded with a force until failure occurred. A one-way ANOVA test was used to analyze the data, followed by Tukey's HSD test (α = 0.05). Results: The milled materials exhibited higher flexural strength than the printed materials. Thermocycling and fatigue reduce the flexural strengths of printed and milled materials. The repaired groups exhibited flexural strengths of 32.80% and 30.67% of the original flexural strengths of printed and milled materials, respectively. Nevertheless, the type of repair material affected the flexural strength of the printed materials; the composite resin exhibited higher flexural strength values than the acrylic resin. Conclusions: The milled denture base materials showed higher flexural strength than the printed ones. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to evaluate the feasibility of monolithic zirconia laminate veneers (MZLV) compared to lithium disilicate laminate veneers (LDLV). Materials and methods: Sixty resin replicas, each prepared with depths of 0.5 mm, 0.7 mm, and 1 mm, were produced using a 3D printer from acrylic teeth. Laminate veneers of these thicknesses were milled from pre-sintered monolithic zirconia (3rd generation) and lithium disilicate blocks. The intaglio surface of MZLV was treated with air abrasion using 110 μm diameter silica-modified aluminium oxide particles and ceramic primer, while LDLV was etched with etchant gel and treated with the ceramic primer before cementation with resin cement. Vertical marginal discrepancy (VMD) was assessed using a stereomicroscope, and a load-to-failure test was conducted using a universal testing machine. Failure modes were evaluated macroscopically on fractured surfaces. Data were analysed statistically using Two-way ANOVA and Bonferroni correction (α = 0.05). Results: LDLV samples exhibited significantly larger VMD compared to MZLV samples across all thicknesses, especially in cervical, palatal, and mean data. Within the LDLV group, load-to-fracture values for 0.7 mm and 1.0 mm thicknesses were similar, whereas for 0.5 mm thickness, it was significantly lower. In the MZLV group, load-to-fracture values were lower for 0.7 mm and 1.0 mm thicknesses compared to LDLV, but higher for 0.5 mm thickness. Conclusions: Material choice and restoration thickness significantly influence laminate veneer restorations' success. MZLV generally exhibits superior vertical marginal fit compared to LDLV, with varying load-to-failure values across different thicknesses. Clinical management of debonding in MZLV is simpler compared to restoration fracture in LDLV. Clinical relevance: Considering clinical factors, MZLV may be a preferable option to LDLV for this restoration with the thickness of 0.5 mm. [ABSTRACT FROM AUTHOR]

Background: Vital pulp therapy maintained functionality, vitality, and asymptomatic teeth. Compared to normal root canal treatment, pulpotomy was more helpful for irreversible pulpitis in adult permanent teeth. The research was aimed to assess effectiveness of vital pulp therapy using mineral trioxide aggregate with Apple Vinegar and Ethylene diamine tetra acetic acid (17%) for five minutes in adult carious exposed pulp of permanent teeth. Methods: Forty patients between 18 and 50 years old with a clinical diagnosis of symptomatic irreversible pulpitis but no periapical radiolucency were then divided randomly into two groups based on the irrigation method; ethylene diamine tetraacetic acid or apple vinegar. If pulpal bleeding could not be managed in less than six minutes, the assigned procedure was abandoned. After mineral trioxide aggregate application as a pulpotomy agent, glass ionomer and composite restoration were placed. Using a visual analogue scale, the pre and post-operative pain were recorded after 2,6,24,48, and 72 h. Success was assessed using radiographic and clinical examination data at three, six, and twelve months. Results: The success rate was discovered to be non-statistically significant in both groups after a year follow-up. Apple vinegar had a lower mean value than ethylene diamine tetra acetic acid at the preoperative baseline pain level, which was significant.Postoperatively, the ethylene diamine tetraacetic acid group reported the greatest mean value after two hours while Apple vinegar group reported the lowest mean values after 48 h (P < 0.05). After 72 h, pain level recorded insignificant difference. Conclusion: Apple vinegar yielded a marginally successful outcome but substantially improved pain alleviation. Trial registration: The trial was registered in Clinical trials.gov with this identifier NCT05970536 on 23/7/2023. [ABSTRACT FROM AUTHOR]

Background: Mechanical complications affect the stability of implant restorations and are a key concern for clinicians, especially with the frequent introduction of new implant designs featuring various structures and materials. This study evaluated the effect of different prosthetic index structure types and implant materials on the stress distribution of implant restorations using both in silico and in vitro methods. Methods: Four finite element analysis (FEA) models of implant restorations were created, incorporating two prosthetic index structures (cross-fit (CF) and torc-fit (TF)) and two implant materials (titanium and titanium-zirconium). A static load was applied to each group. An in vitro study using digital image correlation (DIC) with a research scenario identical to that of the FEA was conducted for validation. The primary strain, sensitivity index, and equivalent von Mises stress were used to evaluate the outcomes. Results: Changing the implant material from titanium to titanium-zirconium did not significantly affect the stress distribution or maximum stress value of other components, except for the implant itself. In the CF group, implants with a lower elastic modulus increased the stress on the screw. The TF group showed better stress distribution on the abutment and a lower stress value on the screw. The TF group demonstrated similar sensitivity for all components. DIC analysis revealed significant differences between TF-TiZr and CF-Ti in terms of the maximum (P < 0.001) and minimum principal strains (P < 0.05) on the implants and the minimum principal strains on the investment materials in both groups (P < 0.001). Conclusions: Changes in the implant material significantly affected the maximum stress of the implant. The TF group exhibited better structural integrity and reliability. [ABSTRACT FROM AUTHOR]

Background: Multi-rooted teeth with extensive dental defects often face challenges in stability and biomechanical failure. High-performance polymer PEEK materials, with properties closer to dentin, show promise in reducing stress concentration and preserving tooth structure. This report aimed to explore the use of a highly retentive polyetheretherketone (PEEK) for manufacturing custom-made split post and core for the restoration of grossly destroyed endodontically treated molars. Clinical considerations: A 40-year-old female patient presented with complaints of loss of tooth substance in the posterior mandibular tooth. This case involved the digital design and fabrication of PEEK split post and core to restore multirooted molar with insufficient dental tissue remnants. The restorations were evaluated over a 3-year follow-up using the World Federation criteria (FDI). The restoration was clinically evaluated through intraoral examination, radiographic assessment, and subjective patient satisfaction, and was deemed clinically good according to FDI criteria. Conclusion: The outstanding mechanical properties of PEEK, coupled with the structure of the split post, provide an effective treatment option for weakened multirooted teeth. Simultaneously, the restoration configuration effectively addressed the challenge of varying postinsertion directions, and the interlocking mechanism between the primary and auxiliary posts enhanced the stability of the post and core. [ABSTRACT FROM AUTHOR]

Background: Long-term success of implant restoration depends on many factors one of them is the sufficient implant stability which is lowered in compromised bone density sites such as the maxilla as it is categorized as type III & IV bone, so searching for a new innovation and updates in implant material and features is very mandatory. So, the aim of this study was to compare between two implant materials (roxolid and traditional titanium) on the primary and secondary stability of implant retained maxillary overdenture. Methods: Eighteen completely edentulous patients were selected. All patients received maxillary implant-retained overdentures and lower complete dentures; patients were divided equally into two groups according to the type of implant materials. Group A received a total number of 36 implants made of roxolid material and Group B received a total number of 36 implants made of traditional titanium alloys. Implant stability was assessed using ostell device, the primary implant stability was measured at the day of implant installation however, secondary implant stability was measured after six weeks of implant placement. Paired t-test was used to compare between primary and secondary stability in the same group and an independent t-test was used to compare between the two groups with a significant level < 0.05. Results: Independent t-test revealed a significant difference between the two groups with p -value = 0.0141 regarding primary stability and p-value < 0.001 regarding secondary stability, as roxolid implant group was statistically higher stability than titanium group in both. Paired t- test showed a statistically significant difference in roxolid implant group with p-value = 0.0122 however, there was non-statistically significant difference in titanium group with p-value = 0.636. Mann Whitney test showed a significant difference between the two groups regarding amount of change in stability with p value = 0.191. roxolid implant group showed a higher amount of change in stability than the titanium implant group. Conclusion: Within the limitation of this study, it could be concluded that: Roxolid implants showed promising results regarding primary and secondary stability compared to conventional Titanium implants and can be a better alternative in implant retained maxillary overdentures. Trial registration: Retrospectively NCT06334770 at 26–3-2024. [ABSTRACT FROM AUTHOR]

Cerium oxide nanoparticles are known for their antibacterial effects resulting from Ce3+ to Ce4+ conversion. Application of such cerium oxide nanoparticles in dentistry has been previously considered but limited due to deterioration of mechanical properties. Hence, this study aimed to examine mesoporous silica (MCM-41) coated with cerium oxide nanoparticles and evaluate the antibacterial effects and mechanical properties when applied to dental composite resin. Cerium oxide nanoparticles were coated on the MCM-41 surface using the sol–gel method by adding cerium oxide nanoparticle precursor to the MCM-41 dispersion. The samples were tested for antibacterial activity against Streptococcus mutans via CFU and MTT assays. The mechanical properties were assessed by flexural strength and depth of cure according to ISO 4049. Data were analyzed using a t-test, one-way ANOVA, and Tukey's post-hoc test (p = 0.05). The experimental group showed significantly increased antibacterial properties compared to the control groups (p < 0.005). The flexural strength exhibited a decreasing trend as the amount of cerium oxide nanoparticle-coated MCM-41 increased. However, the flexural strength and depth of cure values of the silane group met the ISO 4049 standard. Antibacterial properties increased with increasing amounts of cerium oxide nanoparticles. Although the mechanical properties decreased, silane treatment overcame this drawback. Hence, the cerium oxide nanoparticles coated on MCM-41 may be used for dental resin composite. [ABSTRACT FROM AUTHOR]

Introduction: Soft-Liner is an acrylic temporary relining material for the temporary rebasing (relining) of acrylic dentures and tissue conditioning. The use of soft liner as a medium to deliver anti-bacterial and anti-inflammatory medications locally to the site enhances the healing of the soft tissues, further maintaining the mucosa healthy in the transitional healing period. Soft liners modified with Triple Antibiotic Paste (TAP) help in soft tissue healing and reduce post-surgical inflammation. Aim: To evaluate the anti-bacterial, anti-inflammatory efficacy, and cytotoxicity of TAP modified soft liners with conventional soft liners. Materials and Methods: The in-vitro study was conducted in the Gold Laboratory at Saveetha Dental College, Chennai, Tamil Nadu, India, in March 2023. A solution of TAP was prepared and mixed with Gas Chromatography (GC) soft liner material. The antibacterial efficacy against the strains of Staphylococcus aureus, Pseudomonas, and E. faecalis was assessed, and Mueller Hinton Agar was used to identify the zone of inhibition. The Kolmogorov-Smirnov test was conducted to assess the normality of the distribution, and non-parametric tests were performed for further analysis. A chi-square test was used to compare the cytotoxicity of TAP modified soft liners, which was assessed by a Lethality assay for brine shrimps over 24 hours. The Egg albumin denaturation assay was used to assess antiinflammatory properties, with different concentrations of 10 μL, 20 μL, 30 μL, 40 μL, and 50 μL. Human Gingival Fibroblast (HGF) was used for the cell line study, and the isolation of HGF was performed by enzymatic digestion subjected to collagenase (900 u/mL) and dispase (400 u/mL) digestion at 37°C for one hour. Results: In comparing the modified TAP liners to commercially available liners on the basis of antibacterial efficacy, there was increased anti-bacterial efficacy in the TAP modified liners, which increased with increasing concentration, with the maximum being 40.25±14.87 mm for a 1:3 concentration against S. aureus and the least being 23±1.3 mm of unmodified soft liners against Pseudomonas and S. aureus. Different concentrations of 10 μL, 20 μL, 30 μL, 40 μL were used for the anti-inflammatory test, and as the concentration increased, anti-inflammatory activity also increased. The cytotoxicity of the material increased from 10% to 40% as the concentration of TAP rose from 5 μL to 80 μL. Conclusion: TAP shows a better response in managing postoperative inflammation and better soft tissue healing when incorporated into the soft liners. More precise studies are needed to understand the exact mechanism of TAP. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the bisphenol A (BPA) release from four CAD/CAM splint materials: three polycarbonate‐based (DD BioSplint C, Splint Plus Biostar, Temp Premium Flexible) and one polymethylmethacrylate‐based (Temp Basic) material. From each material, ten cylindrical samples (n = 40) were immersed in high‐performance liquid chromatography (HPLC) grade water following ISO 10993‐12 and incubated for 24 h in an incubation shaker at 37°C and 112 rpm. Following BPA derivatization, analysis was performed by high‐performance liquid chromatography–tandem mass spectrometry (HPLC‐MS/MS). After 24 h of incubation, all investigated materials released significant amounts of BPA compared to water blanks. The material‐dependent elution increased in the following order: DD BioSplint C < Splint Plus Biostar < Temp Basic < Temp Premium Flexible. Subtracting extraneous BPA, the concentrations ranged between 2.27 ng/mL and 12.65 ng/mL. After extrapolating the concentrations in relation to the average surface area of occlusal splints, the amount of BPA per mL exceeded the Tolerable Daily Intake (TDI) set by the European Union for a person weighing 70 kg by 1.32–6.16 times. Contrary to the release from previously investigated materials, BPA elution from CAD/CAM splint materials was highly elevated. Considering the increasing adaptation of CAD/CAM techniques, elution from them may represent a relevant BPA source in daily dental practice. [ABSTRACT FROM AUTHOR]

Finite element analysis (FEA) has been used to analyze the behavior of dental materials, mainly in implantology. However, FEA is a mechanical analysis and few studies have tried to simulate the biological characteristics of the healing process of loaded implants. This study used the rule of mixtures to simulate the biological healing process of immediate implants in an alveolus socket and bone‐implant junction interface through FEA. Three‐dimensional geometric models of the structures were obtained, and material properties were derived from the literature. The rule of mixtures was used to simulate the healing periods—immediate and early loading, in which the concentration of each cell type, based on in vivo studies, influenced the final elastic moduli. A 100 N occlusal load was simulated in axial and oblique directions. The models were evaluated for maximum and minimum principal strains, and the bone overload was assessed through Frost's mechanostat. There was a higher strain concentration in the healing regions and cortical bone tissue near the cervical portion. The bone overload was higher in the immediate load condition. The method used in this study may help to simulate the biological healing process and could be useful to relate FEA results to clinical practice. [ABSTRACT FROM AUTHOR]

Introduction: This study aimed to develop a module that incorporates hands‐on and reflective feedback in teaching dental materials science and subsequently analyse undergraduate dental students' learning experiences with the module. Materials and Methods: The module was developed based on the ADDIE (Analyse, Design, Develop, Implement, Evaluate) model. First, a need analysis was conducted, followed by designing the module to address the needs. Next, the module sought experts' feedback and was piloted. The revised module was implemented among all second‐year undergraduate dental students. Finally, a validated questionnaire (5‐point Likert scale items and open‐ended questions) was used to evaluate students' learning experiences. The questionnaire Likert scale items were analysed descriptively, whereas open‐ended responses were analysed using content analysis. Results: In the analysis phase, a slight misalignment in cognitive competency levels was observed, alongside a need for the inclusion of more hands‐on activities. In the design phase, learning objectives and resources were listed. Subsequently, a module consisting of four teaching sessions (3 h each) was developed, and the pilot test showed favourable feedback. The module was then implemented in small groups of 10–12 students. In the evaluation phase, 72 students (97% response rate) completed the questionnaire. The majority of students agreed with all items, with mean scores ranging from 4.53 to 4.72. Open‐ended responses highlighted that hands‐on activities and reflective feedback sessions were useful. Conclusion: Students demonstrated positive learning experiences after participating in the module, advocating for dental educators to consider more hands‐on activities and reflective feedback sessions in teaching dental materials science. [ABSTRACT FROM AUTHOR]

Bioactive glasses in the CaO–MgO–Na2O–P2O5–SiO2–CaF2 system are highly promising materials for bone and dental restorative applications. Furthermore, if thermally treated, they can crystallize into diopside–fluorapatite–wollastonite glass-ceramics (GCs), which exhibit appealing properties in terms of mechanical behaviour and overall bone-regenerative potential. In this review, we describe and critically discuss the genesis, development, properties and applications of bioactive glass "1d" and its relevant GC derivative products, which can be considered a good example of success cases in this class of SiO2/CaO-based biocompatible materials. Bioactive glass 1d can be produced by melt-quenching in the form of powder or monolithic pieces, and was also used to prepare injectable pastes and three-dimensional porous scaffolds. Over the past 15 years, it was investigated by the authors of this article in a number of in vitro, in vivo (with animals) and clinical studies, proving to be a great option for hard tissue engineering applications. [ABSTRACT FROM AUTHOR]

Restorative material selection has become increasingly challenging due to the speed of new developments in the field of dental material science. The present narrative review gives an overview of the current indications for implant abutments and restoration materials for provisional and definitive implant‐supported fixed dental prostheses in partially edentulous patients. For single implant restorations, titanium base abutments for crowns are suggested as an alternative to the conventional stock‐ and customized abutments made out of metal or zirconia. They combine the mechanical stability of a metallic connection with the esthetic potential of ceramics. For multiple‐unit restorations, conical titanium bases especially designed for bridges are recommended, to compensate for deviating implant insertion axes and angulations. Even though titanium base abutments with different geometries and heights are available, certain clinical scenarios still benefit from customized titanium abutments. Indications for the definitive material in fixed implant restorations depend on the region of tooth replacement. In the posterior (not esthetically critical) zone, ceramics such as zirconia (3–5‐Ymol%) and lithium‐disilicate are recommended to be used in a monolithic fashion. In the anterior sector, ceramic restorations may be buccally micro‐veneered for an optimal esthetic appearance. Lithium‐disilicate is only recommended for single‐crowns, while zirconia (3–5‐Ymol%) is also recommended for multiple‐unit and cantilever restorations. Attention must be given to the specific mechanical properties of different types of zirconia, as some feature reduced mechanical strengths and are therefore not indicated for all regions and restoration span lengths. Metal‐ceramics remain an option, especially for cantilever restorations. [ABSTRACT FROM AUTHOR]

Dental materials are challenged by wear processes in the oral environment and should be evaluated in laboratory tests prior to clinical use. Many laboratory wear-testing devices are high-cost investments and not available for cross-centre comparisons. The 'Rub&Roll' wear machine enables controlled application of force, chemical and mechanical loading, but the initial design was not able to test against rigid antagonist materials. The current study aimed to probe the sensitivity of a new 'Rub&Roll' set-up by evaluating the effect of force and test solution parameters (deionized water; water + abrasive medium; acid + abrasive medium) on the wear behaviour of direct and indirect dental resin-based composites (RBCs) compared with human molars against 3D-printed rod antagonists. Molars exhibited greater height loss than RBCs in all test groups, with the largest differences recorded with acidic solutions. Direct RBCs showed significantly greater wear than indirect RBCs in the groups containing abrasive media. The acidic + abrasive medium did not result in increased wear of RBC materials. The developed method using the 'Rub&Roll' wear machine in the current investigation has provided a sensitive wear test method to allow initial screening of resin-based composite materials compared with extracted human molars under the influence of different mechanical and erosive challenges. [ABSTRACT FROM AUTHOR]

Palaeotragus is a common genus of the Giraffidae that was widely distributed in the Neogene strata of Eurasia. Early studies usually placed small giraffids in the Palaeotragus clade, leading to considerable controversy over the validity and systematic classification of this genus. Palaeotragus microdon and Palaeotragus cf. coelophrys are two representative species of Palaeotragus in China, their dental specimens are mainly distinguished by size, causing problems in their actual identification. In this study, several mandibles of a small giraffid found in Linxia Basin, Gansu Province, China (MN 10–13), are studied and identified as Palaeotragus cf. coelophrys. Based on a detailed comparison, the size and morphological variability of the Chinese Palaeotragus dental material are discussed, as well as the validity of the two species and the validity of other Eurasian Palaeotragus. This study reveals that the Chinese Palaeotragus has a continuous sequence of size variability and premolar features, which is insufficient to separate the mandible of the two species. In addition, the type species P. rouenii can be clearly distinguished from the Chinese Palaeotragus by the relatively long lower premolar row, possibly due to the difference in feeding habits. The holotype of P. coelophrys is closely related to Chinese Palaeotragus, while the P. coelophrys mandible from Maragheh (MMTT37 2517) should belong to different species. [ABSTRACT FROM AUTHOR]

Objective Overview Conclusions Clinical Significance This article puts forward consensus recommendations from PROSEC North America regarding single indirect restorations made from ceramic and nonmetallic biomaterials in posterior teeth.The consensus process involved a multidisciplinary panel and three consensus workshops. A systematic literature review was conducted across five databases to gather evidence. The recommendations, informed by findings from systematic reviews and formulated based on a two‐phase e‐Delphi survey, emphasize a comprehensive treatment strategy that includes noninvasive measures alongside restorative interventions for managing dental caries and tooth wear. The recommendations advocate for selecting between direct and indirect restorations on a case‐by‐case basis, favoring inlays and onlays over crowns to align with minimally invasive dentistry principles. The recommendations highlight the critical role of selecting restorative biomaterials based on clinical performance, esthetic properties, and adherence to manufacturer guidelines. They emphasize the importance of precision in restorative procedures, including tooth preparation, impression taking, contamination control, and luting. Regular follow‐up and maintenance tailored to individual patient needs are crucial for the longevity of ceramic and nonmetallic restorations.These PROSEC recommendations provide a framework for dental practitioners to deliver high‐quality restorative care, advocating for personalized treatment planning and minimally invasive approaches to optimize oral health outcomes.The PROSEC North America recommendations highlight the importance of minimally invasive techniques in posterior tooth restorations using ceramic and non‐metallic biomaterials. These principles prioritize tooth structure conservation and personalized treatment planning, essential for enhancing clinical outcomes and long‐term oral health. [ABSTRACT FROM AUTHOR]