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American Journal of Dentistry Jun 2024To evaluate the effect of two resin composites (with different viscosities) and the elevation amount on fracture strength and fracture behavior of molars with and...
PURPOSE
To evaluate the effect of two resin composites (with different viscosities) and the elevation amount on fracture strength and fracture behavior of molars with and without deep margin elevations (DME).
METHODS
70 extracted, caries-free human molars were selected. All teeth were prepared as MOD onlay cavities with a margin 2 mm below the cemento-enamel junction (CEJ) on the mesial and buccal sides and 2 mm above the CEJ on the distal side. The teeth were divided into two groups according to the type of resin composite used in margin elevation, elevated with flowable composite (Universal Flo) or condensable composite (G-Aenial Posterior). These two groups were further subdivided into subgroups in which the elevation was 2, 3, or 4 mm, and a control group in which the non-elevated indirect restoration was directly bonded to the subgingival margin, making a total of seven groups (n= 10). After elevations, the restorations were completed using a nanoceramic CAD-CAM block (Cerasmart A3 HT) and as adhesive cement, G-Cem Link Force. Static force was applied to the restored teeth using a universal testing machine at an angle of 15° until fracture occurred. Fracture strength values were recorded, and fracture types were examined under 6x magnification. One-way ANOVA was carried out to determine the effect of DME on the fracture strength. A two-way ANOVA was conducted to investigate main and interaction effects of the material type used in the elevation and the amount of elevation made on the fracture strength (P< 0.05).
RESULTS
Using flowable or condensable composite as elevation material did not affect the fracture strength of CAD-CAM restorations. Flowable and condensable composites of 2, 3, or 4 mm did not significantly affect fracture strength values for either material. Specimen margins with and without elevation exhibited similar fracture strength values. The type of material used in the elevation and the amount did not affect the fracture strength of teeth.
CLINICAL SIGNIFICANCE
The deep margin elevation technique for teeth with carious lesions extending subgingivally, may be useful in routine practice.
Topics: Humans; Composite Resins; Computer-Aided Design; Dental Stress Analysis; Dental Restoration, Permanent; Molar; Dental Restoration Failure; Materials Testing; Tooth Fractures; In Vitro Techniques; Dental Cavity Preparation; Dental Materials; Dental Marginal Adaptation; Dental Cements; Dentin-Bonding Agents
PubMed: 38899989
DOI: No ID Found -
Materials (Basel, Switzerland) Jun 2024Barium titanate (BaTiO, BTO), conventionally used for dielectric and ferroelectric applications, has been assessed for biomedical applications, such as its utilization...
Barium titanate (BaTiO, BTO), conventionally used for dielectric and ferroelectric applications, has been assessed for biomedical applications, such as its utilization as a radiopacifier in mineral trioxide aggregates (MTA) for endodontic treatment. In the present study, BTO powders were prepared using the sol-gel process, followed by calcination at 400-1100 °C. The X-ray diffraction technique was then used to examine the as-prepared powders to elucidate the effect of calcination on the phase composition and crystalline size of BTO. Calcined BTO powders were then used as radiopacifiers for MTA. MTA-like cements were investigated to determine the optimal calcination temperature based on the radiopacity and diametral tensile strength (DTS). The experimental results showed that the formation of BTO phase was observed after calcination at temperatures of 600 °C and above. The calcined powders were a mixture of BaTiO phase with residual BaCO and/or BaTiO phases. The performance of MTA-like cements with BTO addition increased with increasing calcination temperature up to 1000 °C. The radiopacity, however, decreased after 7 days of simulated oral environmental storage, whereas an increase in DTS was observed. Optimal MTA-like cement was obtained by adding 40 wt.% 1000 °C-calcined BTO powder, with its resulting radiopacity and DTS at 4.83 ± 0.61 mmAl and 2.86 ± 0.33 MPa, respectively. After 7 days, the radiopacity decreased slightly to 4.69 ± 0.51 mmAl, accompanied by an increase in DTS to 3.13 ± 0.70 MPa. The optimal cement was biocompatible and verified using MG 63 and L929 cell lines, which exhibited cell viability higher than 95%.
PubMed: 38893964
DOI: 10.3390/ma17112701 -
Materials (Basel, Switzerland) May 2024The purpose of the present study was to perform a preliminary analysis of the fitting of different fiber-reinforced composite (GFRC) posts to tooth root canals and...
The purpose of the present study was to perform a preliminary analysis of the fitting of different fiber-reinforced composite (GFRC) posts to tooth root canals and determine the resin cement layer thickness. The following GFRC posts were assessed: bundle posts (Rebilda GT, VOCO, Germany), sleeve system (SAP, Angelus Ind, Brazil), and accessory posts (Reforpin, Angelus, Brazil). Twenty-four freshly extracted mandibular single-rooted pre-molars were endodontically treated and divided into six groups, according to the type of GFRC post and resin cement (self-adhesive or conventional dual-cured). Then, specimens were cross-sectioned and inspected by optical microscopy regarding the cement layer thickness and presence of defects such as pores, voids, or fissures were assessed. Bundle and accessory posts revealed a regular distribution of resin cement with a lower number of voids than found with sleeve systems. The sleeve system posts showed poor fitting at the apical portion of the root canals. The type of resin cement did not affect the thickness of the interface, although both bundle and accessory posts allow a better distribution of resin cement and fibers. The present preliminary study reveals interesting insights on the fitting of bundle and accessory posts to root dentin and resin cement layer thickness in oval-shape root canals. The sleeve system posts showed adequate fitting only at the coronal portion of the canals.
PubMed: 38893784
DOI: 10.3390/ma17112520 -
Journal of Clinical Medicine Jun 2024: In everyday dentistry, monolithic single crowns can be cemented with self-adhesive resin cements. The aim of this in vitro study was to evaluate how the marginal...
Three Self-Adhesive Resin Cements and Their Influence on the Marginal Adaptation of Zirconia-Reinforced Lithium Silicate Single Crowns: An In Vitro Scanning Electron Microscope Evaluation.
: In everyday dentistry, monolithic single crowns can be cemented with self-adhesive resin cements. The aim of this in vitro study was to evaluate how the marginal adaptation of full monolithic zirconia-reinforced lithium silicate (ZLS) single crowns is influenced by three different self-adhesive resin cements. : Forty-five typodont teeth fully prepared for full monolithic crowns were divided into three groups (fifteen each) for the use of three different self-adhesive resin cements. A fourth control group (Temp-bond) was created by taking five teeth from each group before cementation with self-adhesive resin cements. All forty-five abutments were scanned using a Primescan intra-oral scanner (IOS), followed by computer-aided design (CAD) and computer-aided manufacturing (CAM) of zirconia-reinforced lithium silicate (ZLS) full crowns using a four-axis machine. Initially, the crowns of the control group were fixed to the abutments using Temp-bond, and the marginal gap was evaluated using a scanning electron microscope (SEM). After removing the control group crowns from the abutments, fifteen crowns in each group were cemented using a different self-adhesive resin cement and observed under SEM for evaluation of the marginal gap. A Kolmogorov-Smirnov test was performed, indicating no normal distribution ( < 0.05), followed by Mann-Whitney tests (α = 0.05). : The total mean marginal gap of the temp-bond control group was significantly lower compared to all three groups of self-adhesive resin cement ( < 0.0005). The total mean marginal gap of the G-cem ONE group was significantly lower compared to the TheraCem group ( < 0.026) and RelyX U200 group ( < 0.008). The total mean marginal gap of the TheraCem group was significantly higher than the G-cem ONE group ( < 0.026) but showed no significant difference with the RelyX U200 group ( > 0.110). : All four groups showed a clinically acceptable marginal gap (<120 microns). Although all three groups of self-adhesive resin cement showed a significant increase in the marginal gap compared to the temp-bond control group, they were within the limits of clinical acceptability. Regarding the marginal gap, in everyday dentistry, it is acceptable to use all three self-adhesive resin cements, although the G-cem ONE group exhibited the lowest marginal gap for ZLS single crowns.
PubMed: 38893040
DOI: 10.3390/jcm13113330 -
Clinical Oral Investigations Jun 2024This study aimed to evaluate the effect of ultrasonic activation of etch-and-rinse and self-etch adhesive systems on the bond strength of resin cement to irradiated root...
OBJECTIVE
This study aimed to evaluate the effect of ultrasonic activation of etch-and-rinse and self-etch adhesive systems on the bond strength of resin cement to irradiated root dentin.
MATERIALS AND METHODS
Eighty human maxillary anterior teeth were distributed into 8 groups (n = 10), according to the type of adhesive system used (etch-and-rinse and self-etch), the ultrasonic activation of the adhesive systems, and the dentin condition (irradiated or non-irradiated - 70 Gy). Endodontic treatment was performed followed by fiberglass post-space preparation. After fiberglass posts' luting, the roots were transversely sectioned on dentin discs and submitted to the push-out bond strength test (0.5 mm/min). The fractured specimens were analyzed under a stereomicroscope and Scanning Electron Microscope (SEM) for failure mode classification. One of the dentin discs was analyzed under SEM to evaluate the characteristics of the adhesive interface.
RESULTS
Irradiated specimens had lower bond strength than non-irradiated specimens (P < 0.0001). Ultrasonic activation of both adhesive systems increased the bond strength of the resin cement to irradiated dentin (P < 0.0001). Radiotherapy significantly affected the failure mode in the middle (P = 0.024) and apical thirds (P = 0.032) (adhesive failure).
CONCLUSION
Non-irradiated specimens had a more homogeneous adhesive interface. When ultrasonically activated, both adhesive systems showed a greater number of resinous tags, regardless of the dentin condition.
CLINICAL RELEVANCE
Ultrasonic activation of adhesive systems is a feasible strategy to enhance fiberglass posts retention in oncological patients.
Topics: Humans; Resin Cements; Dental Bonding; Post and Core Technique; Dentin; Materials Testing; Microscopy, Electron, Scanning; In Vitro Techniques; Dentin-Bonding Agents; Dental Stress Analysis; Surface Properties; Tooth Root; Ultrasonics; Acid Etching, Dental; Incisor; Glass
PubMed: 38890207
DOI: 10.1007/s00784-024-05782-4 -
Dental Materials : Official Publication... Jun 2024Baghdadite (CaZrSiO) cements of various composition have been investigated in this study regarding an application as endodontic filling materials.
OBJECTIVES
Baghdadite (CaZrSiO) cements of various composition have been investigated in this study regarding an application as endodontic filling materials.
METHODS
Cements were either obtained by mixing mechanically activated baghdadite powder with water (maBag) or by subsequently substituting the ß-tricalcium phosphate (ß-TCP) component in a brushite forming calcium phosphate cement. The cements were analyzed for their mechanical performance, injectability, radiopacity, phase composition and antimicrobial properties.
RESULTS
The cements demonstrated sufficient mechanical performance with a compressive strength of ∼1 MPa (maBag) and 2.3 - 17.4 MPa (substituted calcium phosphate cement), good injectability > 80 % depending on the powder to liquid ratio and an intrinsic radiopacity of 1.13 - 2.05 mm aluminum equivalent. Immersion in artificial saliva proved their bioactivity by the formation of calcium phosphate and calcium silicate precipitates on the cement surface. The bacterial activity of Staphylococcus aureus cultured on the surface of the cements was found to be similar compared to clinical standard ProRoot MTA cement or even reduced by a factor of 3 for Streptococcus mutans.
SIGNIFICANCE
In combination with their antibacterial properties, baghdadite cements are thought to have the potential to fulfil the clinical requirements for endodontic filling materials.
PubMed: 38890091
DOI: 10.1016/j.dental.2024.05.026 -
Primary Dental Journal Jun 2024A technique is outlined for utilising a polymeric composite reinforced with glass fibres in a three-dimensional mesh as a post-core in aesthetic cases. The clinical...
A technique is outlined for utilising a polymeric composite reinforced with glass fibres in a three-dimensional mesh as a post-core in aesthetic cases. The clinical procedure involves obtaining an impression of the root canal space, scanning the definitive cast, and milling a fibre-reinforced composite post-core. Subsequently, the intra-radicular post-core is cemented using an adhesive resin cement. The use of custom-made computer-aided design-computer-aided manufacturing (CAD-CAM) fibre-reinforced composite post-core facilitates repairability, provides better adaptation to the root canal space, avoids uneven cement thickness, ensures chemical adhesion to resin cement, and promotes favourable aesthetics when combined with all-ceramic crowns.
Topics: Computer-Aided Design; Humans; Post and Core Technique; Composite Resins; Dental Prosthesis Design; Glass; Resin Cements; Crowns; Esthetics, Dental; Dental Prosthesis Retention; Dental Materials; Cementation
PubMed: 38888075
DOI: 10.1177/20501684241249546 -
Primary Dental Journal Jun 2024Silver diamine fluoride (SDF) and atraumatic restorative treatment (ART) are treatment modalities that are minimally invasive and used for the prevention and control of... (Review)
Review
Silver diamine fluoride (SDF) and atraumatic restorative treatment (ART) are treatment modalities that are minimally invasive and used for the prevention and control of dental caries. The amalgamation of these two techniques has led to the development of silver modified atraumatic restorative treatment (SMART). In this approach the carious lesion is restored with glass-ionomer cement (GIC) after SDF application. SMART effectively arrests caries without removing additional tooth structure, making it a promising option for caries management in children who lack cooperative ability.This article reviews the literature on SMART, the evidence regarding its applications in dental practice, its advantages, drawbacks, the scope for research, and clinical use.
Topics: Humans; Dental Caries; Silver Compounds; Dental Atraumatic Restorative Treatment; Fluorides, Topical; Quaternary Ammonium Compounds; Glass Ionomer Cements; Cariostatic Agents; Child
PubMed: 38888074
DOI: 10.1177/20501684241249545 -
Scientific Reports Jun 2024This split-mouth blinded randomized controlled study compared the efficacy of a desensitizing agent with oxalate/resin polymer and a universal adhesive containing... (Randomized Controlled Trial)
Randomized Controlled Trial
Desensitizing efficacy of a universal dentin adhesive containing mesoporous bioactive glass on dentin hypersensitivity: a randomized clinical trial with a split-mouth model.
This split-mouth blinded randomized controlled study compared the efficacy of a desensitizing agent with oxalate/resin polymer and a universal adhesive containing mesoporous bioactive glass (MBG) for dentin hypersensitivity (DH) relief, using Schiff sensitivity score (SSS) and visual analog scale (VAS). Split quadrants containing teeth with DH were treated with either MS Coat ONE or Hi-Bond Universal with MBG as the functional additive. Assessments at baseline, immediately post-application, and at 1- and 2-week follow-ups used standardized stimulus protocols (air, cold, and acid). The SSS difference was the primary outcome, while the VAS difference was the secondary outcome. A mixed linear effect model performed statistical analysis. Immediate DH reduction occurred in response to air stimuli, with a significant decrease in Group HB than in Group MS (p = 0.0178). Cold stimulus reduction exhibited a gradual cumulative effect, with consistently greater reductions in Group HB than in Group MS (p ≤ 0.0377). Both groups effectively managed acidic stimuli, with no significant differences (p > 0.05). The VAS scores decreased gradually over the follow-up period (p < 0.0001). This study highlights the differential efficacy of treatments for various DH triggers and recommends specific approaches based on different stimulus types. The universal adhesive containing MBG demonstrated DH relief potential, promising efficacy identical to or superior to that of a dedicated desensitizing agent. Further research exploring the long-term efficacy and underlying mechanisms is warranted. The universal adhesive containing MBG can be adopted as an in-office desensitizing agent for DH relief. The desensitizing efficacy of universal adhesive matches or surpasses dedicated agents for air and cold stimuli.
Topics: Humans; Dentin Sensitivity; Female; Male; Dentin Desensitizing Agents; Adult; Glass; Treatment Outcome; Ceramics; Dental Cements; Young Adult; Middle Aged; Porosity
PubMed: 38886498
DOI: 10.1038/s41598-024-64404-x -
BioMed Research International 2024To evaluate the enamel bonding ability and orthodontic adhesive resin degree of conversion using the experimental bracket design. . Thirteen bovine teeth were used in...
OBJECTIVE
To evaluate the enamel bonding ability and orthodontic adhesive resin degree of conversion using the experimental bracket design. . Thirteen bovine teeth were used in the study. The experimental bracket was modified with a translucent region in the center of its body. After enamel etching, Orthocem orthodontic adhesive (FGM, Joinville, Brazil) was applied on the bracket base for bonding. The groups were divided as follows ( = 10 per group): (1) control (CB) with standard brackets and (2) spot bracket (SB) with experimental brackets featuring a 0.8 mm translucent region at the center using carbide bur. Shear bond strength (SBS) was evaluated after 24 hours in a universal testing machine and adhesive remnant index (ARI). The degree of conversion (DC) was analyzed using Raman spectroscopy ( = 3 per group). Data were then analyzed using Student's -test and Mann-Whitney statistical methods.
RESULTS
The SB group exhibited a higher mean SBS (10.33 MPa) compared to the CB Group (8.77 MPa). However, there was no statistical difference between the groups ( = 0.376). Both SB and CB groups had a mean ARI score of 1. Raman analysis revealed a higher degree of conversion in the SB group (49.3%) compared to the CB group (25.9%).
CONCLUSIONS
The experimental support showed a higher degree of adhesive conversion, although there was no significant increase in bond strength.
Topics: Orthodontic Brackets; Animals; Cattle; Dental Bonding; Dental Enamel; Composite Resins; Shear Strength; Polymerization; Materials Testing; Dental Cements; Resin Cements
PubMed: 38884017
DOI: 10.1155/2024/7457900