Search Results (21)

Background: Cervical restorations remain clinically challenging due to complex anatomy, limited enamel availability, and difficulties in achieving reliable adhesion at dentin or cementum margins. Polymerization shrinkage and marginal leakage are frequent causes of failure. Although the Closing Gap Technique has been proposed to improve marginal adaptation in cervical restorations, evidence supporting its medium- to long-term clinical performance is limited. The aim of this case report was to evaluate the clinical effectiveness of the Closing Gap Technique in the restoration of carious and non-carious cervical lesions. Materials and Methods: Two patients presenting with cervical lesions were treated using the Closing Gap Technique. One case involved carious cervical lesions, while the second included multiple non-carious cervical lesions. Restorations were performed following an enamel-anchored incremental layering protocol with resin composite. Clinical evaluations were conducted at 8 years (case #1) and 2 years (case #2) post-treatment, respectively. Results: Both cases demonstrated favorable clinical outcomes at follow-up. The restorations exhibited good marginal integrity, satisfactory esthetics, absence of marginal discoloration, no secondary caries, and no signs of debonding. The only minor defect observed was slight chipping of one of the restorations. Conclusions: Within the limitations of this case report, the Closing Gap Technique showed stable and predictable medium- and long-term clinical performance, supporting its use as a viable restorative approach for managing cervical lesions in daily clinical practice. Full article

Objectives: To study the effects of internal and marginal polymerization shrinkage stress and distribution in different resin composite class III dental restorations in relation to the restorative technique using numerical finite element analysis (FEA). Methods: A 3D model of a human hemi-maxilla with a sound maxillary central incisor were created. Four class III distal cavities were shaped and differently restored. Four groups of resin composite combinations were analyzed: group C (three increments of conventional composite); group B (two increments of bulk-fill composite); group FC (flowable base + three increments of conventional composite); and group FB (flowable bulk-fill base + two increments of conventional composite). The resulting four models were exported to FEA software for static structural analysis. Polymerization shrinkage was simulated using thermal analogy, and stress distribution was analyzed using the Maximum Principal Stress criterion at the marginal and internal cavity interfaces. Results: Group FC showed the highest stress at the level in the proximal region (9.05 MPa), while group FB showed the lowest (4.48 MPa). FB also exhibited the highest internal dentin stress, indicating potential risks for long-term bond degradation. In the cavo-surface incisal angle, the average peak stress across all groups was 3.76 MPa. At the cervical cavo-surface angle, stress values were 3.3 MPa (C), ~3.36 MPa (B), 3.41 MPa (FC), and 3.27 MPa (FB). Conclusions: Restorative technique did not significantly influence marginal stress distribution in class III composite restorations. However, the bevel area at the cervical margin showed the highest concentration of shrinkage stress. Full article

Isotopic analyses are useful tools with a wide range of applications, including environmental studies, archaeology and biomedicine. Founded in 2019 at the University of Campania “Luigi Vanvitelli”, the iCONa laboratory specialises in stable isotope mass spectrometry, with a particular focus on cultural heritage. The laboratory performs carbon, nitrogen and oxygen isotopic analyses, including the most recent advances in compound-specific stable isotope analysis of amino acids (CSIA-AAs). In addition to these analytical services, iCONa provides chemical and physical sample preparation for a variety of sample types. This paper focuses on our applications in the field of cultural heritage, exploring how the analysis of stable isotopes performed on archaeological remains can be used to reconstruct past subsistence strategies and human behaviours. We also discuss the challenges inherent in isotopic analysis and recent methodological advances in the field. Full article

The aim of this study was to evaluate, in vitro, the void formation and marginal adaptation in Class II cavities restored with preheated and injected bulk-fill resin composites. Eighty third molars received Class II cavities on their mesial and distal surfaces and were randomly distributed into eight groups (n = 10) according to material (Filtek Universal—control, incremental technique; Filtek One Bulk-Fill; Admira Fusion X-tra Bulk-Fill; VisCalor Bulk-Fill) and the temperature of the material (24 °C or 68 °C). The restored teeth were scanned using a SkyScan 1173 microtomograph. The percentage of internal voids (%IV) was analyzed using CTan software (version 1.23.02) and the percentages of continuous margins (%CM) in enamel and dentin were analyzed using Dataviewer software (version 1.5.6.2). The data of %IV and %CM were subjected to two-way ANOVA on ranks, followed by Tukey’s test (α = 0.05). At 24 °C, Filtek Universal had a greater %IV (1.89%) (p < 0.05), which did not differ significantly from that of Admira Fusion X-tra Bulk-Fill (0.29%) (p > 0.05). Filtek One Bulk-Fill (0.07%) and VisCalor Bulk-Fill (0.07%) had lower %IV (p < 0.05). Preheating resulted in a significantly lower %IV for Admira Fusion X-tra Bulk-Fill (p < 0.05). Temperature did not significantly influence marginal adaptation (p > 0.05). VisCalor Bulk-Fill achieved significantly higher %CM in dentin (98%) at 24 °C (p < 0.05). It was concluded that bulk-fill-injected resin composites tend to have fewer internal voids than conventional resin composites using the incremental technique, and the injection of the resin composite into the cavity seems to be more important for marginal adaptation than the preheating procedure. Full article

To investigate the effect of different sandblasting settings on the shear bond strength (SBS) in the repair of resin composite, specimens (resin composite, enamel, and dentin; each group n = 16) were sandblasted by varying the parameters of air pressure (0.2/0.3/0.4 MPa), angle (45/90°), particle size (27/50 μm), tip size (0.8/1.2 mm), and distance (2/5/10 mm) prior to the application of a universal adhesive (Adhese Universal) and resin composite (adhesive area: 7.07 mm²). The specimens were subjected to artificial aging (10,000 cycles, 5–55 °C) prior to (resin composite only) and after repair. Groups without mechanical pretreatment and resin composite incremental bond strength served as controls. Statistical analysis was performed using ANOVAs, post hoc tests, and Chi²-tests (p < 0.05). Only air pressure and distance impacted SBS (p ≤ 0.049). However, resin composite SBS did not differ from the resin composite incremental SBS within all sandblasting settings (positive control: 21.0 ± 5.0 MPa, p ≥ 0.566). While sandblasting did not impact bond strength on enamel (control: 20.5 ± 5.1 MPa, p ≥ 0.999), most settings resulted in a lower bond strength on dentin (control: 20.1 ± 4.7 MPa, p ≤ 0.027). In conclusion, sandblasting significantly improves resin composite repair bond strength, while application parameters are of minor relevance. Full article

Background: Material-dependent parameters have an important impact on the efficiency of light polymerization. The present in vitro study aimed to investigate the influence of the increment thickness and shade of nano- and nanohybrid resin composites on the transmission of curing light. Methods: Three contemporary resin composites were evaluated: Tetric EvoCeram^® (TEC); Venus Diamond^® (VD); and Filtek Supreme XTE^® (FS XTE). Light transmission (LT) was recorded in accordance with the sample thickness (0.5 to 2.7 mm) and the shade. Polymerized samples were irradiated for 10 s each using the high-power LED curing light Celalux 2 (1900 mW/cm²). LT was simultaneously recorded using the MARC Patient Simulator (MARC-PS). Results: LT was strongly influenced by the composite layer thickness. For 0.5 mm-thick samples, a mean power density of 735 mW/cm² was recorded at the bottom side. For the 2.7 mm samples, a mean power density of 107 mW/cm² was measured. Only LT was markedly reduced in the case of darker shades. From A1 to A4, LT decreased by 39.3% for FS XTE and 50.8% for TEC. Dentin shades of FS XTE and TEC (A2, A4) showed the lowest LT. Conclusions: The thickness and shade of resin composite increments strongly influences the transmission of curing light. More precise information about these parameters should be included in the manufacture manual. Full article

(1) Background: The objective of the current investigation was to determine how different dark chocolate concentrations impacted the enamel and dentine microhardness. (2) Methods: Twenty noncarious premolar teeth extracted for orthodontic reasons were used in this study. Each tooth was divided mesiodistally to obtain 40 specimens of enamel and dentine 4 × 4 mm. Initial and final assessments of the surface microhardness of the enamel and dentine were created using a Digital Micro Vickers Hardness Tester (Laryee, Beijing, China) under (0.24 N load for 15 s). Four random groups (n = 10) were created: G1 (control, immersed in artificial saliva), G2 (70%), G3 (85%), and G4 (100% dark chocolate). Each sample underwent four cycles of 60-s immersion in suggested concentrations, followed by 30 min in artificial saliva. The attained values underwent statistical analysis employing SPSS version 26, with the utilization of T-tests and ANOVA. (3) Results: The results revealed a significant, incremental increase in the average microhardness values for enamel, specifically 61.72 ± 22.729, 64.17 ± 23.397, and 109.15 ± 34.625, and for dentin from 57.91 ± 8.332 to 72.29 ± 2.752 and ultimately reaching 88.67 ± 8.602, corresponding to the escalating concentrations of dark chocolate (70%, 85%, and 100%) (p < 0.001). (4) Conclusions: Immersing the specimens in different concentrations of dark chocolate had a significant positive impact on the microhardness of both enamel and dentine. Full article

The purpose of this study was to investigate the functional load capacity of the periodontal ligament (PDL) in a full arch maxilla and mandible model using a numerical simulation. The goal was to determine the functional load pattern in multi- and single-rooted teeth with full and reduced periodontal support. CBCT data were used to create 3D models of a maxilla and mandible. The DICOM dataset was used to create a CAD model. For a precise description of the surfaces of each structure (enamel, dentin, cementum, pulp, PDL, gingiva, bone), each tooth was segmented separately, and the biomechanical characteristics were considered. Finite Element Analysis (FEA) software computed the biomechanical behavior of the stepwise increased force of 700 N in the cranial and 350 N in the ventral direction of the muscle approach of the masseter muscle. The periodontal attachment (cementum–PDL–bone contact) was subsequently reduced in 1 mm increments, and the simulation was repeated. Quantitative (pressure, tension, and deformation) and qualitative (color-coded images) data were recorded and descriptively analyzed. The teeth with the highest load capacities were the upper and lower molars (0.4–0.6 MPa), followed by the premolars (0.4–0.5 MPa) and canines (0.3–0.4 MPa) when vertically loaded. Qualitative data showed that the areas with the highest stress in the PDL were single-rooted teeth in the cervical and apical area and molars in the cervical and apical area in addition to the furcation roof. In both single- and multi-rooted teeth, the gradual reduction in bone levels caused an increase in the load on the remaining PDL. Cervical and apical areas, as well as the furcation roof, are the zones with the highest functional stress. The greater the bone loss, the higher the mechanical load on the residual periodontal supporting structures. Full article

Objective: The goal of this study was to compare the pulp temperature increase during light curing of different composite thicknesses in deep class I cavities using two thermal sensing tools. Methodology: Round occlusal class I cavities with a remaining dentin thickness (RDT) of 1 mm from the cavity floor were performed on 15 extracted sound molars. Samples were divided into three groups (n = 5). In group A, cavities were restored using the Filtek Z350 XT conventional composite through the incremental filling technique, whereas group B cavities were restored using the Filtek Bulk-Fill flowable composite through the bulk-fill technique. Specimens of the Filtek Bulk-Fill flowable composite using the incremental filling technique were used to restore cavities in group C. An infrared thermal camera (IRT; Flir, Wilsonville, OR, USA) and K-type thermocouple (Perfect Prime TC0520, New York, NY, USA) were used to measure the heat generated during composite photo-polymerization. Results: There were no significant differences within the same group using either the thermocouple or IRT (p > 0.05). One-way ANOVA showed no significant differences between groups A and C (p > 0.05), whereas group B was significantly different from groups A and C with each sensing tool (p < 0.05). Conclusion: IRT and thermocouple heat readings were comparable. Based on the current findings, the bulk-fill technique resulted in the lowest heat generation among the groups. Therefore, increasing the light-curing time and the number of composite increments was directly correlated with increases in intra-pulpal temperature. Full article

Recently, biomimetic bioactive biomaterials have been introduced to the market for dental pulp capping. This systematic review and meta-analysis aimed to determine any variation between the effect of using TheraCal LC and other bioactive biomaterials for pulp capping is different, as measured by dentin increment and clinical success. The risk of bias was assessed using the Risk of Bias 2 and Newcastle–Ottawa tools for randomized clinical trials and observational studies. A search for relevant articles was performed on five databases. Additionally, the quality of the included studies was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria. A summary of individual studies and a meta-analysis were performed. The odds ratio of data from clinical success was combined using a random-effects meta-analysis. The meta-analysis results showed homogeneity between the studies (I² = 0%). They revealed that the clinical success showed no differences between the patients who received TheraCal LC, light-cured calcium silicate-based biomimetic biomaterial, for dental pulp capping or the comparator biomaterials (p > 0.5). However, the certainty of the evidence was low to moderate due to the risk of bias in the included studies. Full article

A more-and-more-accepted alternative to the time-consuming and technique-sensitive, classic, incremental-layering technique of resin-based composites (RBCs) is their placement in large increments. The so-called bulk-fill RBCs had to be modified for a higher polymerization depth and already have a 20-year history behind them. From the initial simple mechanisms of increasing the depth of cure by increasing their translucency, bulk-fill RBCs have evolved into complex materials with novel polymerization mechanisms and bioactive properties. However, since the materials are intended to replace the tooth structure, they must be comparable in mechanical behavior to the substance they replace. The study compares already established bulk-fill RBCs with newer, less-studied materials and establishes their relationship to dentin with regard to basic material properties such as hardness and indentation modulus. Instrumented indentation testing enables a direct comparison of tooth and material substrates and provides clinically relevant information. The results underline the strong dependence of the measured properties on the amount of filler in contrast to the small influence of the material classes into which they are classified. The main difference of RBCs compared to dentin is a comparable hardness but a much lower indentation modulus, emphasizing further development potential. Full article

ECC is a significant therapeutic and social problem and a global burden on public health. The aim of this clinical trial was to test whether a 2-week daily consumption of chewing tablets containing thermally inactivated L. salivarius reduces the 12-month caries increment compared to the control group. The investigation was a single-center, randomized, controlled open-label, blinded end-point evaluation trial in two parallel groups. At baseline, 140 generally healthy children between 3 and 6 years of age with or without ECC were randomly assigned to the probiotic test group (n = 70) or to the treatment as the usual control group (n = 70). The primary outcome measure was the 1-year increment in caries incidence and prevalence. Secondary endpoints assessed were the initial, cavitated and obvious dentinal caries increment as well as the measurement of dental plaque accumulation, as an indicator of the ECC risk. Data were collected through the clinical assessment of the children’s caries (dmft and ICDAS II) and oral hygiene status (DI-S of OHI-S index). Caries incidence and prevalence were statistically significantly lower in the probiotic group versus the control group (p < 0.001 and p = 0.0075). The initial and final mean OHI-S scores in the probiotic group did not show any significant differences. In conclusion, the regular short-term intake of probiotics may reduce caries development. Our findings suggest that self-administered probiotic therapy may provide a good complement to increase the effectiveness of individual preventive home care in preschool children. This is the first clinical study evaluating the effect of a short-term probiotic intervention on reducing early childhood caries with 12 months of follow-up. Full article

Due to the increasing interest in direct restoration, there is a need to address the shortcomings of these restorations, mainly by increasing the longevity of complex direct restorations. The present study aimed to evaluate the tensile strength differences in the complex restoration of posterior teeth with dentin replacement constructed by fiber and non-fiber materials. The samples were extracted from the mandibular permanent-molar and prepared using a complex cavity. The cavity was subsequently restored with the centripetal incremental technique using a nano-fill composite and different base materials, namely fiber dentin replacement, non-fiber dentin replacement, and flowable composite. The universal testing machine was used to consider the tensile strength and the fracture patterns were assessed using stereomicroscopy, followed by Scanning Electron Microscopy (SEM) examination. The data were statistically analyzed using the one-way ANOVA test. No significant differences were noted in the tensile strength of the three base materials. By using stereomicroscopy and SEM, the adhesive fracture patterns were observed more clearly in the cavities with fiber-based dentin replacement, whereas mixed fracture patterns were evident in cavities with non-fiber dentin replacement and flowable composite bases. The results indicated that the addition of fiber in dentin replacement did not affect the tensile strength in the complex restoration. Therefore, dentin replacement of both fiber and non-fiber materials is applicable as a base material for complex restoration of the posterior tooth. Full article

Background: Diode-assisted endodontics is nowadays utilized for pulp space disinfection, but little is known on the bonding potential of this lased root dentin when the tooth is restored with an intracanal polymer post. Objectives: to investigate the influence of diode laser irradiation settings, in laser-assisted endodontics, on the intraradicular bonding of composite materials. Methods: Sixteen two-rooted, maxillary first premolars were collected, prepared up to F4 (Protaper Universal. Dentsply-Maillefer, Ballaigues, Switzerland), and randomly assigned in two groups: group A (chopped mode or short pulse), diode irradiated according to protocol, pulse 25 ms, power 2.5 W, and group B (microchopped mode or ultrashort pulse), pulse 25 μs, peak power 12 W (both groups GentleRay. KaVo Dental, Biberach an der Riss, Germany). Buccal canals were irradiated, palatal ones served as controls. Canals were then obturated, post space was created in all canals, and quartz-fiber posts (ICE light Danville. Danville Materials, San Ramon, CA, USA) were cemented by self-etch self-curing cement (Max Cem Elite. Kerr, West Collins Orange, CA, USA) (Max Cem Elite. Kerr, Brea, CA, USA). A week later, teeth were sectioned horizontally in 1 mm increments. Push-out test was conducted in a Zwick testing machine (Zwick Roell, Ulm, Germany) at 1 mm/min speed, and the force required to dislodge the post from each specimen (F-max) was recorded. Weibull regression models were applied for statistical analyses. Results: Differences in F-max by group (control vs. chopped mode vs. microchopped mode) and height (meaning the apical-to-coronal position of each specimen along the root) were statistically significant (p < 0.05 in all cases). Conclusions: Short pulses (or chopped mode) had a profound positive effect on the quality of intraradicular bonding, while Ultrashort pulses (or microchopped mode) affected it negatively. In addition, apically positioned bonding proved weaker compared with more coronally located specimens. Full article

A guideline called FRAMM, which is an acronym in Swedish for the most important parts of this guideline, namely “fluoride”, “advice”, “arena”, “motivation” and “diet”, was implemented in 2008 in the Västra Götaland Region in Sweden. This guideline included fluoride varnish applications performed at school twice a year at six-monthly intervals for all 12- to 15-year-olds, together with lessons on oral health. The aim of this analysis was to estimate the long-term cost-effectiveness, using prognostic calculations, of the FRAMM Guideline for 12- to 15-year-olds, compared with routine care, until the participants were 23 years old. A cost-effectiveness analysis was performed from a health care perspective, based on four years of verified data and seven years of prognosis. Data from FRAMM were combined with cost data from price lists in Sweden. The cost-effectiveness was analyzed by relating the difference in costs to the difference in the number of approximal surfaces with fillings and/or dentin lesions (DFSa). The analysis shows that FRAMM was considered dominant compared to the controls in all alternative scenarios, hence costs were prognosed to be lowered and outcomes were prognosed to be improved. A dental health program like the FRAMM Guideline with fluoride varnish during the caries risk period from 12 to 15 years is predicted to be cost-effective in the longer perspective. To further study the actual long-term caries increment after a preventive dental health program would be of great interest to verify these results. Full article