-
Frontiers in Bioengineering and... 2024[This corrects the article DOI: 10.3389/fbioe.2024.1354241.].
[This corrects the article DOI: 10.3389/fbioe.2024.1354241.].
PubMed: 38812918
DOI: 10.3389/fbioe.2024.1423030 -
Clinical Oral Investigations May 2024This study aimed to evaluate the effect of restorations made with a glass-hybrid restorative system (GHRS), a high-viscosity glass ionomer restorative material (HVGIC),...
OBJECTIVES
This study aimed to evaluate the effect of restorations made with a glass-hybrid restorative system (GHRS), a high-viscosity glass ionomer restorative material (HVGIC), a high-viscosity bulk-fill composite resin (HVB), a flowable bulk-fill composite resin (FB), and a nanohybrid composite resin (NH), which are commonly preferred in clinical applications on the fracture resistance of teeth in-vitro.
MATERIALS AND METHODS
One hundred intact human premolar teeth were included in the study. The teeth were randomly divided into ten groups (n = 10). No treatment was applied to the teeth in Control group. Class II cavities were prepared on the mesial surfaces of the remaining ninety teeth in other groups. For restoration of the teeth, a GHRS, a HVGIC, a HVB, a FB, and a NH were used. Additionally, in four groups, teeth were restored using NH, GHRS, and HVGIC with open and closed-sandwich techniques. After 24 h, fracture resistance testing was performed. One-way ANOVA and Tukey HDS tests were used for statistical analysis of the data.
RESULTS
The fracture resistance values of Control group were statistically significantly higher than those of GHRS, HVGIC, FB, NH, HVGIC-CS, GHRS-OS, and HVGIC-OS groups(p < 0.05). There was no statistically significant difference observed between the fracture resistance values of Control, HVB, and GHRS-CS groups (p > 0.05).
CONCLUSION
It can be concluded that the use of HVB and the application of GHRS with a closed-sandwich technique may have a positive effect on the fracture resistance of teeth in the restoration of wide Class II cavities.
CLINICAL RELEVANCE
The use of high-viscosity bulk-fill composite resin and the application of glass-hybrid restorative system with the closed-sandwich technique in the restoration of teeth with wide Class II cavities could increase the fracture resistance of the teeth.
Topics: Composite Resins; Humans; In Vitro Techniques; Dental Restoration, Permanent; Glass Ionomer Cements; Materials Testing; Tooth Fractures; Dental Stress Analysis; Viscosity; Bicuspid; Surface Properties; Dental Cavity Preparation; Acrylic Resins
PubMed: 38809289
DOI: 10.1007/s00784-024-05745-9 -
BMC Oral Health May 2024Retrieval of cement-retained implant-supported restorations is intriguing in cases of screw loosening. Detecting the estimated size of the screw access hole (SAH) could...
BACKGROUND
Retrieval of cement-retained implant-supported restorations is intriguing in cases of screw loosening. Detecting the estimated size of the screw access hole (SAH) could decrease destruction to the prosthesis and preserve the crown.
OBJECTIVES
To precisely localize loose implant screws through cemented crowns to reduce crown damage after screw loosening.
MATERIALS AND METHODS
In this in vitro study, 60 cement-retained implants supported 30 zirconia-based, and 30 ceramics fused to metal (CFM) lower molar crowns were invented, and each was subdivided into three subgroups (10 each). In group I (AI/BI) (control), SAH was created with the aid of orthopantomography (OPG). In contrast, in group II (zirconia-crown), SAH was created with the aid of CBCT + 3D printed surgical guide with a 2 mm metal sleeve in subgroups IIA/IIIA and CBCT + MAR was used to develop SAH in subgroups IIB/IIIB. SEM and Micro-CT scanned the SAH openings to determine the diameter of the hole, cracking, chipping, and chipping volume.
RESULTS
Regarding the effect of plane CBCT and CBCT + MAR on prepared crowns, a highly significant association between group I with group II (p = 0.001) and group III (p = 0.002) was detected. Regarding the cracking of SAH, significant differences between the zirconium crown and CFM restoration (p = 0.009) were found, while for the chipping, no significant association was seen between groups (p = 0.19).
CONCLUSIONS
CBCT, either as a plane CBCT or with MAR, significantly improved the accuracy of drilling the screw channel and decreased injury to the existing restoration and abutment, aiding in better localization of SAH in loosened implant abutment screws.
Topics: Crowns; In Vitro Techniques; Dental Prosthesis, Implant-Supported; Humans; Dental Restoration Failure; X-Ray Microtomography; Dental Cements; Cone-Beam Computed Tomography; Cementation; Zirconium; Microscopy, Electron, Scanning; Bone Screws
PubMed: 38807096
DOI: 10.1186/s12903-024-04369-5 -
BMC Oral Health May 2024Erbium lasers safely offer the possibility of reuse for debonded restorations. Since these lasers have a high affinity for water molecules, they are absorbed by resin...
BACKGROUND
Erbium lasers safely offer the possibility of reuse for debonded restorations. Since these lasers have a high affinity for water molecules, they are absorbed by resin cement causing explosive ablation of the cement and thus, the restoration debonds. The efficiency of this process depends on many factors, including the ceramic type, its chemical composition and thickness. Therefore, this study was designed to test the time taken to debond ultrathin occlusal veneers made of three types of milled ceramic materials and evaluate the integrity of these restorations after debonding.
METHODS
Three ceramic types were evaluated in this study: lithium disilicate (IPS Emax CAD), highly condensed lithium disilicate (GC initial®LiSi), and translucent zirconia (Katana zirconia STML). Each group consisted of 8 occlusal veneers of 0.5 mm thickness. The samples were cemented to the occlusal surfaces of the upper molar teeth. An Er; Cr: YSGG laser was applied to the occlusal veneers using the scanning method, and time until debonding was calculated. The debonded samples were then inspected under a stereomicroscope for possible damage. Numerical data are presented as the mean with 95% confidence interval (CI), standard deviation (SD), minimum (min.) and maximum (max.) values. Normality and variance homogeneity assumptions were confirmed using Shapiro-Wilk's and Levene's tests, respectively. Data were normally distributed and were analyzed using one-way ANOVA followed by Tukey's post hoc test. The significance level was set at p < 0.05 for all tests. Statistical analysis was performed with R statistical analysis software version 4.3.2 for Windows (R Core Team (2023). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. URL https://www.R-project.org/).
RESULTS
There was no significant difference in debonding time between the different materials (p = 0.995). The longest debonding time was found for Katana STML (87.52 ± 20.45) (seconds), followed by Emax (86.94 ± 20.63) (seconds), while the lowest value was found for LiSi initial (86.14 ± 25.16) (seconds). In terms of damage to the debonded veneers, The Emax and zirconia samples showed no damage. However, 40% of the LiSi samples fractured during debonding, and 20% exhibited cracks. Only 40% of the LiSi samples were sound after debonding.
CONCLUSION
Er; Cr: YSGG laser can be used efficiently to remove ceramic occlusal veneers. However, its effect on LiSi restorations needs further research.
Topics: Dental Veneers; Computer-Aided Design; Ceramics; Dental Porcelain; Humans; Zirconium; Lasers, Solid-State; Dental Debonding; Materials Testing
PubMed: 38802801
DOI: 10.1186/s12903-024-04314-6 -
Cureus Apr 2024Background Pulp necrosis in incomplete root formation halts dentine development, resulting in larger canals with fragile walls and an open apex, complicating canal...
Histologic Assessment of a Fast-Set Mineral Trioxide Aggregate (MTA) and Two Novel Antibacterial-Enhanced Fast-Set MTAs for Apexification and Periapical Healing of Teeth With Incomplete Root Formation in a Rat Model: An In Vivo Animal Study.
Background Pulp necrosis in incomplete root formation halts dentine development, resulting in larger canals with fragile walls and an open apex, complicating canal instrumentation and apical stop formation. Bioactive endodontic cements such as mineral trioxide aggregate (MTA) are crucial for creating artificial apical barriers or inducing apical foramen closure, but challenges remain regarding their antimicrobial efficacy and cytotoxicity. Modifications to MTA formulations aim to address these concerns. Methods This in vivo animal study involved 80 Wistar albino rats, with incomplete root formation induced by pulp exposure. Rats were divided into four groups receiving different MTA formulations for apexification: conventional MTA, modified MTA, and MTA enhanced with metronidazole or doxycycline. Histopathological evaluations were conducted at seven and 28 days post-treatment to assess calcific barrier formation, inflammatory reactions, and antimicrobial efficacy. Results By day 7, modified MTA formulations exhibited enhanced antibacterial activity compared to conventional MTA (p = 0.000), with fewer inflammatory reactions and microorganisms. By day 28, modified formulations showed superior calcific barrier formation, particularly in the metronidazole- and doxycycline-enhanced groups compared to conventional MTA (p = 0.000). These outcomes suggest that modifications to MTA formulations improve antimicrobial efficacy and calcific barrier formation in vivo. Conclusion Novel modified MTA formulations, particularly those enhanced with metronidazole or doxycycline, exhibit superior antibacterial efficacy and calcific barrier formation compared to conventional MTA. Further long-term studies are warranted to validate these findings for potential clinical translation.
PubMed: 38800318
DOI: 10.7759/cureus.59064 -
BMC Oral Health May 2024High speed electric handpieces have recently been growing in popularity among dental professionals. Advantages include smoother surface preparation and increased cutting... (Comparative Study)
Comparative Study
BACKGROUND
High speed electric handpieces have recently been growing in popularity among dental professionals. Advantages include smoother surface preparation and increased cutting efficiency.
AIM
The primary objective was to compare enamel surface roughness following resin cleanup after bracket debonding using highspeed air turbine versus electric handpiece. The secondary objective was to record the time needed for resin-clean up.
METHOD
Forty deidentified freshly extracted human premolars were cleaned and sectioned at the cement-enamel junction. The crowns were embedded in acrylic blocks. Enamel surface roughness parameters (Ra, Rz, Rp and Rv) were measured using a stylus profilometer. Brackets were bonded using a light-cure orthodontic adhesive and stored in distilled water for 24 h. Following bracket debonding, the specimens were randomly divided into 2 groups: First group: resin clean-up was carried out using a 12-fluted carbide bur mounted on a high-speed air turbine; and second group: where an electric handpiece was used. Surface roughness parameters were measured following resin clean up and after polishing using pumice and a rubber cup. Time needed for resin clean-up was recorded. Differences in enamel surface roughness and time between groups were compared using repeated measures ANOVA and independent samples t-test, respectively at P ≤ 0.05.
RESULTS
The electric handpiece groups showed significantly higher values for Ra, Rz and Rp both following resin cleanup and polishing. Time taken for resin cleanup was significantly longer for the electric handpiece group.
CONCLUSION
Considering both surface roughness and time, electric handpiece do not seem to add greater effectiveness or efficiency to resin cleanup following orthodontic bracket debonding.
Topics: Humans; Surface Properties; Dental Debonding; Dental Enamel; Dental High-Speed Equipment; In Vitro Techniques; Resin Cements; Orthodontic Brackets; Time Factors; Bicuspid; Dental Polishing
PubMed: 38796434
DOI: 10.1186/s12903-024-04339-x -
Medicina (Kaunas, Lithuania) May 2024: Sealant application is a proven method to prevent occlusal caries; however, long-term studies on this topic are scarce. This study aimed to assess the survival rate...
: Sealant application is a proven method to prevent occlusal caries; however, long-term studies on this topic are scarce. This study aimed to assess the survival rate and clinical effectiveness of glass ionomer cement (GIC) and resin-based sealants (RBSs) on second permanent molars over a long-term follow-up period. Sixteen patients aged 11-13 years with all four completely erupted permanent second molars were enrolled in the study. All patients attended 1-year and 3-year follow-ups; however, one participant did not respond after 10 years and was excluded from the final analyses. The oral health status evaluation was based on WHO criteria. A total of 32 teeth received an RBS (Clinpro), and a further 32 teeth were sealed with GIC (Fuji IX). The sealant retention was determined according to the Kilpatrick criteria after 1 year, 3 years, and 10 years, respectively. Statistical analysis included a chi-square test, the Kaplan-Meier method, and the Cox proportional hazard model. : At baseline, seven boys and eight girls participated in the study, with a mean age of 12.3 ± 0.9 years. The 1-year follow-up results revealed that 90% of the RBSs and 43.3% of the GIC sealants were completely retained, and no caries lesions were recorded ( = 0.01). The 3-year follow-up results showed that 23.3% of the RBSs and 0% of the GIC sealants demonstrated complete retention ( = 0.034). Moreover, 10.0% of the occlusal surfaces in the RBS group and 13.3% of the occlusal surfaces in the GIC group were filled ( > 0.05). A total of 6.7% of the RBSs showed complete retention. One-third of the sealed teeth (30.0% of the teeth sealed with RBSs and 36.7% of teeth applied with GIC) were filled after 10 years. The Kaplan-Meier analysis demonstrated a higher survival rate in the RBS group when compared with the GIC over the entire follow-up period ( = 0.001). : Although the survival rate of RBSs was higher than GIC sealants, their effectiveness in preventing fissure caries in permanent second molars did not differ significantly over a 10-year follow-up.
Topics: Humans; Glass Ionomer Cements; Female; Male; Child; Follow-Up Studies; Pit and Fissure Sealants; Adolescent; Dental Caries; Molar; Survival Analysis; Composite Resins; Resin Cements
PubMed: 38792939
DOI: 10.3390/medicina60050756 -
Journal of Prosthodontics : Official... May 2024To evaluate the fracture resistance of chairside computer-aided design and computer-aided manufacturing (CAD-CAM) lithium disilicate mandibular posterior crowns with...
Influence of occlusal thickness on the fracture resistance of chairside milled lithium disilicate posterior full-coverage single-unit prostheses containing virgilite: A comparative in vitro study.
PURPOSE
To evaluate the fracture resistance of chairside computer-aided design and computer-aided manufacturing (CAD-CAM) lithium disilicate mandibular posterior crowns with virgilite of different occlusal thicknesses and compare them to traditional lithium disilicate crowns.
MATERIALS AND METHODS
Seventy-five chairside CAD-CAM crowns were fabricated for mandibular right first molars, 60 from novel lithium disilicate with virgilite (CEREC Tessera, Dentsply Sirona), and 15 from traditional lithium disilicate (e.max CAD, Ivoclar Vivadent). These crowns were distributed across five groups based on occlusal thickness and material: Group 1 featured CEREC Tessera crowns with 0.8 mm thickness, Group 2 had 1.0 mm thickness, Group 3 had 1.2 mm thickness, Group 4 with 1.5 mm thickness, and Group 5 included e.max CAD crowns with 1.0 mm thickness. These crowns were luted onto 3D-printed resin dies using Multilink Automix resin cement (Ivoclar Vivadent). Subsequently, they underwent cyclic loading (2,000,000 cycles at 1 Hz with a 275 N force) and loading until fracture. Scanning electron microscopy (SEM) assessed the fractured specimens. Statistical analysis involved one-way ANOVA and the Kruskal-Wallis Test (α = 0.05).
RESULTS
Fracture resistance varied significantly (<0.001) across mandibular molar crowns fabricated from chairside CAD-CAM lithium disilicate containing virgilite, particularly between crowns with 0.8 mm and those with 1.2 and 1.5 mm occlusal thickness. However, no significant differences were found when comparing crowns with 1, 1.2, and 1.5 mm thicknesses. CEREC Tessera crowns with 1.5 mm thickness exhibited the highest resistance (2119 N/mm), followed by those with 1.2 mm (1982 N/mm), 1.0 mm (1763 N/mm), and 0.8 mm (1144 N/mm) thickness, whereas e.max CAD crowns with 1.0 mm occlusal thickness displayed the lowest resistance (814 N/mm).
CONCLUSIONS
The relationship between thickness and fracture resistance in the virgilite lithium disilicate full-coverage crowns was directly proportional, indicating that increased thickness corresponded to higher fracture resistance. No significant differences were noted among crowns with thicknesses ranging from 1 to 1.5 mm. This novel ceramic exhibited superior fracture resistance compared to traditional lithium disilicate.
PubMed: 38790151
DOI: 10.1111/jopr.13870 -
Journal of Functional Biomaterials May 2024There is a vast amount of published literature concerning dental veneers; however, the effects of tooth preparation, aging, veneer type, and resin cement type on the... (Review)
Review
There is a vast amount of published literature concerning dental veneers; however, the effects of tooth preparation, aging, veneer type, and resin cement type on the failure of dental veneers in laboratory versus clinical scenarios are not clear. The purpose of the present narrative review was to determine the principal factors associated with failures of dental veneers in laboratory tests and to understand how these factors translate into clinical successes/failures. Articles were identified and screened by the lead author in January 2024 using the keywords ''dental veneer", "complication", "survival rate", "failure", and "success rate" using PubMed/Medline, Scopus, Google Scholar, and Science Direct. The inclusion criteria included articles published between January 1999 and January 2024 on the topics of preparation of a tooth, aging processes of the resin cement and veneer, translucency, thickness, fabrication technique of the veneer; shade, and thickness of the resin cement. The exclusion criteria included articles that discussed marginal and internal fit, microhardness, water sorption, solubility, polishability, occlusal veneers, retention, surface treatments, and wear. The results of the present review indicated that dental veneers generally have a high survival rate (>90% for more than 10 years). The amount of preserved enamel layer plays a paramount role in the survival and success rates of veneers, and glass-ceramic veneers with minimal/no preparation showed the highest survival rates. Fracture was the primary failure mechanism associated with decreased survival rate, followed by debonding and color change. Fractures increased in the presence of parafunctional activities. Fewer endodontic complications were associated with veneer restorations. No difference was observed between the maxillary and mandibular teeth. Fractures can be reduced by evaluation of occlusion immediately after cementation and through the use of high-strength veneer materials, resin cements with low moduli, and thin layers of highly polished veneers. Debonding failures can be reduced with minimal/no preparation, and immediate dentin sealing should be considered when dentin is exposed. Debonding can also be reduced by preventing contamination from blood, saliva, handpiece oil, or fluoride-containing polishing paste; through proper surface treatment (20 s of hydrofluoric acid etching for glass ceramic followed by silane for 60 s); and through use of light-cured polymerization for thin veneers. Long-term color stability may be maintained using resin cements with UDMA-based resin, glass ceramic materials, and light-cure polymerization with thin veneers.
PubMed: 38786642
DOI: 10.3390/jfb15050131 -
Journal of Functional Biomaterials May 2024This study aimed to compare the impact of CAD/CAM closed systems and open systems on the marginal gap of monolithic zirconia-reinforced lithium silicate (ZLS) ceramic...
The Impact of Open versus Closed Computer-Aided Design/Computer-Aided Manufacturing Systems on the Marginal Gap of Zirconia-Reinforced Lithium Silicate Single Crowns Evaluated by Scanning Electron Microscopy: A Comparative In Vitro Study.
This study aimed to compare the impact of CAD/CAM closed systems and open systems on the marginal gap of monolithic zirconia-reinforced lithium silicate (ZLS) ceramic crowns, as both systems are used in everyday dentistry, both chair-side and laboratory. For the closed system, 20 plastic teeth were scanned by a Primescan intra-oral scanner (IOS), and for the open system, the same number of plastic teeth were scanned by Trios 4 IOS. For the closed system, CEREC software was used, and for the open system, EXOCAD software was used. All 40 ZLS crowns were grinded by the same four-axis machine and cemented with Temp-bond, followed by self-adhesive resin cement. For each type of cement, an evaluation of the marginal gap was conducted by scanning electron microscopy (SEM). Before comparisons between the groups, a Kolmogorov-Smirnov test was performed on the study variables showing a normal distribution ( > 0.05). Independent tests (α = 0.05) and paired-sample tests (α = 0.05) were used. The independent test found no significant mean marginal gap differences in the zirconia-reinforced lithium silicate crowns bonded with Temp-bond and scanned by Primescan (28.09 μm ± 3.06) compared to Trios 4 (28.94 μm ± 3.30) ( = 0.401), and there was no significant mean marginal gap differences in zirconia-reinforced lithium silicate crowns bonded with self-adhesive resin cement (Gcem ONE) and scanned by Primescan (46.70 μm ± 3.80) compared to Trios 4 (47.79 μm ± 2.59) ( = 0.295). Paired-sample tests showed significantly higher mean marginal gaps with Gcem ONE compared to Temp-bond for the total mean marginal gap when scanning with Primescan ( = 0.0005) or Trios 4 ( = 0.0005). In everyday dentistry, both closed systems (Primescan with Cerec) and open systems (Trios 4 with Exocad) can be used to achieve an acceptable (<120 µm) marginal gap for ZLS CELTRA DUO single crowns. There is a significant difference between cementation with Temp-bond and Gcem ONE self-adhesive resin cement ( < 0.05).
PubMed: 38786641
DOI: 10.3390/jfb15050130