-
Cureus May 2024To compare the bond strength of two types of resin cement to that of additive manufacturing (AM) or cast cobalt-chromium (Co-Cr) alloys.
OBJECTIVE
To compare the bond strength of two types of resin cement to that of additive manufacturing (AM) or cast cobalt-chromium (Co-Cr) alloys.
MATERIALS AND METHODS
Two types of resin luting cement, composite resin and methyl methacrylate (MMA), were bonded to AM or cast Co-Cr alloys, and shear bond tests were performed after seven days of storage in distilled water at 37°C. Co-Cr alloy adhesive elements AM to the enamel surface of the labial aspect of a bovine mandibular central incisor crown were bonded with two types of resin luting cement and subjected to 1,000 cycles of storage in water for one day and 28 days or thermal cycling, followed by shear bonding tests. Residual cement on the metal and enamel surfaces after the bonding tests was evaluated using an optical microscope. The normality of the results was evaluated using statistical software Statcel4, analysis of variance, or Kruskal-Wallis test, depending on normality, and multiple comparison tests were performed using the Tukey-Kramer or Steel-Dwass tests.
RESULTS
After one day, the shear bond strength (SBS) was 25.9 MPa for Panavia V5 (PV; Kuraray Noritake Dental Corporation, Niigata, Japan) and 23.5 MPa for Super-Bond (SB; Sun Medical Corporation, Shiga, Japan), with no significant difference between the two cement types (P > 0.05). After 28 days, the SBS decreased to 4.1 MPa for PV and 6.7 MPa for SB, showing a significant difference between the two cements (P < 0.05). Following 1,000 thermal cycles, the SBS was 2.0 MPa for PV and 5.6 MPa for SB, with SB exhibiting a significantly higher value (P < 0.05). The adhesive strength was significantly lower after 28 days of storage and thermal cycling compared to after one day of storage (P < 0.05). The Co-Cr alloy exhibited more residual cement on the enamel surface due to interfacial fracture with the resin cement. The Co-Cr alloy showed more residual cement on the enamel surface due to interfacial fracture with the resin cement.
CONCLUSION
MMA-based resin cement showed optimal bond strength and may be suitable for clinical use in computer-aided design (CAD)/computer-aided manufacturing (CAM) orthodontic appliances.
PubMed: 38916016
DOI: 10.7759/cureus.61041 -
Cureus May 2024Dental materials with dentine regenerative properties are preferred over conventional materials. Calcium silicate cements, such as Biodentine, are bioactive and offer...
BACKGROUND
Dental materials with dentine regenerative properties are preferred over conventional materials. Calcium silicate cements, such as Biodentine, are bioactive and offer excellent sealing ability, making them ideal for various dental treatments.
OBJECTIVES
This study aimed to fabricate bioactive calcium silicates infused with titanium (Ti) and strontium (Sr) to optimize their neo-angiogenic, antimicrobial, and regenerative properties while maintaining mechanical stability.
METHODOLOGY
Ti- and Sr-infused calcium silicate cements were synthesized, and their mineral phases were characterized using X-ray diffraction. Morphological and elemental analyses were performed using field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDS). Raman spectroscopy was used to confirm the formation of bioactive material. A hemocompatibility assessment was conducted to evaluate blood compatibility.
RESULTS
The presence of Ca, SiO, and SrTiO mineral phases indicated the successful infusion of Ti and Sr into the calcium silicate cement. FESEM and EDS revealed interconnected small spheres and rods in the silicate network with the relevant elemental compositions. Raman spectra verified that Si-O-Si and Ti-O-Ti vibrations exist, validating the formation of a bioactive material. The hemocompatibility assessment demonstrated optimal blood compatibility.
CONCLUSIONS
This study successfully fabricated an improved calcium silicate-based material with enhanced regenerative properties and excellent biocompatibility. This newly formed substrate holds promise for providing superior restorative solutions and aiding in conservative treatment modalities during dental procedures.
PubMed: 38910673
DOI: 10.7759/cureus.60863 -
Medicina Oral, Patologia Oral Y Cirugia... Jul 2024Glass ionomers may be a good alternative to composite resin restorations in special needs patients with challenging behaviours. The present study was carried out to... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Glass ionomers may be a good alternative to composite resin restorations in special needs patients with challenging behaviours. The present study was carried out to evaluate the restorative efficacy of glass ionomer in the occlusal cavities of permanent molars among patients with special needs after one year of follow-up.
MATERIAL AND METHODS
A randomized split-mouth study was made of a cohort of patients with special needs. First and second permanent molars with occlusal caries were treated with glass ionomer, silver amalgam and composite resin. Assessments were made at 3, 6 and 12 months, using a scale based on the original code of Ryge and the USPHS criteria.
RESULTS
A total of 34 patients and 102 restorations comprised the study sample. The survival rate of both the glass ionomer and silver amalgam was 100%, versus 97.1% in the case of composite resin. The glass ionomer afforded good marginal adaptation and stable color, with no fractures or secondary caries.
CONCLUSIONS
The glass ionomer remained successfully for one year in the occlusal cavities of the permanent molars, with the same survival rate as silver amalgam, and better survival than composite resin, in the patients with special needs.
Topics: Humans; Male; Female; Dental Restoration, Permanent; Adult; Glass Ionomer Cements; Young Adult; Dental Caries; Dental Care for Disabled; Middle Aged; Dental Amalgam; Adolescent; Composite Resins; Acrylic Resins; Silicon Dioxide
PubMed: 38907639
DOI: 10.4317/medoral.26537 -
BMC Oral Health Jun 2024Failure of orthodontic bracket bonds is a common occurrence during orthodontic treatment. This study investigated the impact of Er: YAG laser-based removal of adhesive... (Comparative Study)
Comparative Study
BACKGROUND
Failure of orthodontic bracket bonds is a common occurrence during orthodontic treatment. This study investigated the impact of Er: YAG laser-based removal of adhesive from the bases of metal and ceramic brackets for re-bonding.
METHODS
A total of 168 extracted premolars were collected from patients. 84 metal brackets were used to be bonded on the buccal surface of the premolars in Groups 1, 2, 3 and 4, while 84 ceramic brackets were applied in Groups I, II, III and IV. Group 1/I represented the initial bonding group, with Group 2/II being the re-bonding group with new brackets, while Groups 3/III and 4/ IV received recycled brackets treated by Er: YAG laser or flaming respectively. Both the first and second de-bonding were performed in all samples using a universal testing machine to determine the shear bond strength (SBS). The adhesive remnant index (ARI) was evaluated using a stereo-microscope. The new and the treated bracket bases were evaluated using scanning electron microscopy (SEM). Differences in initial bonding and re-bonding ability were analyzed through one-way ANOVAs, and differences in ARI were assessed with the Kruskal-Wallis test.
RESULTS
Greater amounts of adhesive residue were observed on ceramic brackets treated by laser. The SBS values for recycled metal brackets in Group 3 (26.13 MPa) were comparable to Group 1 (23.62 MPa) whereas they differed significantly from Group 4 (12.54 MPa). No significant differences in these values were observed when comparing the 4 groups with ceramic brackets. ARI score in Group 4 (2-3 points) differed significantly from the three other groups (P < 0.05). For Group I, II, III and IV, similar ARI scores were observed (P > 0.05). SEM analysis didn't show apparent damage of bracket bases consisting of either metal or ceramic material treated by Er: YAG laser.
CONCLUSIONS
Er: YAG laser treatment was superior to flame treatment as a means of removing adhesive without damaging the brackets. SBS values and ARI scores following Er: YAG laser treatment were similar to those for new brackets, offering further support for Er: YAG laser treatment as a viable means of recycling debonded brackets.
Topics: Orthodontic Brackets; Lasers, Solid-State; Humans; Dental Bonding; Ceramics; Dental Debonding; Shear Strength; Dental Stress Analysis; Microscopy, Electron, Scanning; Materials Testing; Surface Properties; Bicuspid; Dental Alloys; Resin Cements
PubMed: 38902669
DOI: 10.1186/s12903-024-04504-2 -
BMC Oral Health Jun 2024Low mechanical properties are the main limitation of glass ionomer cements (GICs). The incorporation of elastomeric micelles is expected to enhance the strength of GICs... (Comparative Study)
Comparative Study
BACKGROUND
Low mechanical properties are the main limitation of glass ionomer cements (GICs). The incorporation of elastomeric micelles is expected to enhance the strength of GICs without detrimentally affecting their physical properties and biocompatibility. This study compared the chemical and mechanical properties, as well as the cytotoxicity, of elastomeric micelles-containing glass ionomer cement (DeltaFil, DT) with commonly used materials, including EQUIA Forte Fil (EF), Fuji IX GP Extra (F9), and Ketac Molar (KT).
METHOD
Powder particles of GICs were examined with SEM-EDX. Setting kinetics were assessed using ATR-FTIR. Biaxial flexural strength/modulus and Vickers surface microhardness were measured after immersion in water for 24 h and 4 weeks. The release of F, Al, Sr, and P in water over 8 weeks was analyzed using a fluoride-specific electrode and ICP-OES. The toxicity of the material extract on mouse fibroblasts was also evaluated.
RESULTS
High fluoride levels in the powder were detected with EF and F9. DT demonstrated an initial delay followed by a faster acid reaction compared to other cements, suggesting an improved snap set. DT also exhibited superior flexural strength than other materials at both 24 h and 4 weeks but lower surface microhardness (p < 0.05). EF and F9 showed higher release of F, Al, and P than DT and KT. There was no statistically significant difference in fibroblast viability among the tested materials (p > 0.05).
CONCLUSIONS
Elastomeric micelles-containing glass ionomer cement (DT) exhibited satisfactory mechanical properties and cytocompatibility compared with other materials. DT could, therefore, potentially be considered an alternative high-strength GIC for load-bearing restorations.
Topics: Glass Ionomer Cements; Animals; Mice; Materials Testing; Micelles; Fibroblasts; Hardness; Elastomers; Flexural Strength; Aluminum; Fluorides; Strontium; Polycarboxylate Cement; Cell Survival; Microscopy, Electron, Scanning; Surface Properties; Pliability; Kinetics; Spectroscopy, Fourier Transform Infrared; Stress, Mechanical; Time Factors; Biocompatible Materials
PubMed: 38902666
DOI: 10.1186/s12903-024-04468-3 -
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 -
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 -
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