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PloS One 2022Although placing a vent hole on the occlusal surface of the implant crown can reduce cervical marginal cement extrusion, it has disadvantages. Transferring the hole to...
Should the vent hole of posterior implant crowns be placed on the lateral surface? An in vitro study of the hydrodynamic feature of cement extrusion and retention ability.
Although placing a vent hole on the occlusal surface of the implant crown can reduce cervical marginal cement extrusion, it has disadvantages. Transferring the hole to the buccal or lingual surface of the posterior implant crown could therefore be an alternative solution. This study investigated the effect of transferring the vent hole to the lateral side of the implant posterior crown on the hydrodynamics of excess cement extrusion and the crown's retention ability. Specially fabricated posterior implant crowns were divided into five groups: crowns with an occlusal hole (OH), occlusal lateral hole (OLH), middle lateral hole (MLH), cervical lateral hole (CLH), and no hole (NH). Each set of implant analog-abutment-crown specimens was wrapped in a polymethylacrylate base. The base of the implant crown was divided into four 90-degree quadrants along the diagonal of the square base with a pen mark. Cement was used to bond the crowns and the abutments, and the weight of cement extrusions at the vent holes and the abutment cervical margins were calculated. The distribution of cement extrusion at the margin was photographed in each quadrant, and the areas of surface coverage of cement extrusion were compared with ImageJ software. Retentive strength was measured as the dislocation force using a universal testing machine. One-way analysis of variance was used for result analysis. The cervical marginal cement extrusions of crowns with lateral holes (OLH, MLH, and CLH) were significantly less than that of NH crowns (P<0.05), but more than that of OH crowns (P<0.05). Subgroup analysis among the lateral hole groups indicated that the higher the position of the lateral hole, the lower the weight of the cement extrusion, and the smaller the total distribution area of cement extrusion. The cement extrusion distribution area was larger in the quadrant with the hole than in those opposite and next to the hole. Retention strength comparison indicated no significant difference between crowns with NH, OH, or lateral holes. Transferring the vent hole of the posterior implant crown to the lateral side could reduce cement extrusion at the cervical margin while reducing retention strength deterioration and the esthetic drawbacks caused by occlusal hole opening.
Topics: Hydrodynamics; Crowns; Glass Ionomer Cements; Bone Cements; Tooth; Dental Cements; Dental Abutments; Materials Testing; Cementation
PubMed: 36264869
DOI: 10.1371/journal.pone.0276198 -
Odontology Jan 2020Glass ionomer cement is a widely used luting agent for indirect restorations but presents inferior mechanical properties compared to resin cement due to its low elastic...
Glass ionomer cement is a widely used luting agent for indirect restorations but presents inferior mechanical properties compared to resin cement due to its low elastic modulus. This study evaluated the mechanical and adhesion properties of glass ionomer luting cements reinforced with nano-sized hydroxyapatite particles (HA). The nano-sized HA particles were synthesized using the co-precipitation technique and the resulting precipitate was characterized using X-ray diffraction analysis (XRD), field emission scanning electron (FESEM) and transmission electron microscopy (TEM). HA particles were incorporated into the glass powder (FUJI I, GC) and the luting agent was manipulated in a liquid to powder ratio of 3:1 into 6% by weight after determining the best ratio. The flexural strength of the luting agent and shear bond strength of dentin were analyzed and compared to other luting agents namely, (a) glass ionomer (FUJI I), (b) resin-modified glass ionomer (RelyX Luting Plus) and (c) adhesive resin cement (RelyX U200). Failure types after debonding from dentin were evaluated under SEM. Flexural strength and bond strength data were analyzed using one-way ANOVA and Tukey's tests (alpha = 0.001). Addition of 6 w % HA particles in the range of 80-150 nm enhanced the flexural strength (30.97 ± 5.9 versus 11.65 ± 5.63) and shear bond strength (0.97 ± 0.41 versus 0.39 ± 0.16) of a conventional glass ionomer luting agent significantly compared to the non-reinforced ones when manipulated at a liquid to powder ratio of 3:1 (P < 0.001). While conventional glass ionomer, HA-reinforced glass ionomer and resin-modified glass ionomer specimens showed exclusively mixed type of failures, adhesive resin cement showed cohesive failures within the resin cement. Increased mechanical and adhesion potential of the experimental glass ionomer luting agent after incorporation of HA particles could expand the scope of application of this cement.
Topics: Composite Resins; Dental Bonding; Dental Cements; Durapatite; Glass Ionomer Cements; Materials Testing; Resin Cements; Stress, Mechanical; Surface Properties
PubMed: 31028514
DOI: 10.1007/s10266-019-00427-5 -
Dental Materials Journal 2012The objective of this study was to evaluate the sealing ability and antibacterial activity of Ca3SiO5/CaCl2 composite cement. Fifty maxillary anterior teeth were...
The objective of this study was to evaluate the sealing ability and antibacterial activity of Ca3SiO5/CaCl2 composite cement. Fifty maxillary anterior teeth were instrumented according to step-back technique and filled with experimental and control materials. To evaluate the sealing ability, a fluid transport model using glucose was employed for quantitative analysis of endodontic microleakage. To evaluate antibacterial activity, E. colias (ATCC 25922) was cultivated on agar plates. Results showed that the sealing ability of Ca3SiO5/CaCl2 composite cement and cortisomol paste were higher than that of zinc oxide-eugenol (ZOE) cement, and that no significant difference was observed between Ca3SiO5/CaCl2 composite cement and cortisomol paste. On antibacterial activity, Ca3SiO5/CaCl2 composite cements composed of varying amounts of CaCl2 (0-15%) exhibited similar levels of activity against E. coliasas calcium hydroxide cement, whereas cortisomol paste had little effect on E. colias. All these results suggested that Ca3SiO5/CaCl2 composite cement demonstrated good potential for root canal treatment applications.
Topics: Analysis of Variance; Anti-Infective Agents; Calcium Chloride; Calcium Compounds; Colony Count, Microbial; Dental Bonding; Dental Leakage; Escherichia coli; Glass Ionomer Cements; Glucose; Humans; Root Canal Filling Materials; Root Canal Therapy; Silicate Cement; Silicates; Zinc Oxide-Eugenol Cement
PubMed: 22864215
DOI: 10.4012/dmj.2011-260 -
The Journal of Prosthetic Dentistry Aug 2019Limited information is available on the effect of LOCATOR abutment length and luting cement type on retention to intraradicular dentin in overdentures.
STATEMENT OF PROBLEM
Limited information is available on the effect of LOCATOR abutment length and luting cement type on retention to intraradicular dentin in overdentures.
PURPOSE
The purpose of this in vitro study was to evaluate the effect of the length of a commercially available LOCATOR abutment and cement type on retention in the root canal.
MATERIAL AND METHODS
Eighty LOCATOR abutments with a standard length of 6 mm were obtained. Half of them were shortened to 3 mm. Eighty recently extracted single-rooted teeth were divided into 2 groups. The post space was prepared to 6 mm in the first group and 3 mm in the second. After preparation, the LOCATOR abutments were luted with one of the following cements: dual-polymerized glass-reinforced resin cement (Parapost Paracore), dual-polymerized resin cement (Variolink II), self-adhesive resin cement (RelyX Unicem), and conventional cement (zinc phosphate). The tensile force required for the removal of the LOCATOR abutments from their corresponding roots was recorded. Data were statistically analyzed with 2-way ANOVA and the Tukey multiple comparison test.
RESULTS
Both the cement type (P<.001) and the length of the LOCATOR abutment (P<.001) significantly affected the mean tensile forces. Dual-polymerized glass-reinforced resin cement (Parapost Paracore) presented significantly higher mean tensile forces for the LOCATOR abutment retention among all cements (P<.05).
CONCLUSIONS
Regardless of the length, LOCATOR abutments luted with Parapost Paracore resin cement presented higher mean resistance to tensile forces compared with those luted with the other cements. LOCATOR abutments of 6 mm in length were more resistant to tensile forces than those of 3 mm in length in combination with all cements.
Topics: Composite Resins; Dental Bonding; Dental Prosthesis Retention; Dental Stress Analysis; Dentin; Denture, Overlay; Glass Ionomer Cements; Materials Testing; Post and Core Technique; Resin Cements
PubMed: 31326148
DOI: 10.1016/j.prosdent.2019.04.023 -
BMC Oral Health Dec 2022In clinical settings, tooth preparation for prefabricated zirconia crowns (PZCs) in the primary dentition varies widely. However, knowledge about the biomechanical...
BACKGROUND
In clinical settings, tooth preparation for prefabricated zirconia crowns (PZCs) in the primary dentition varies widely. However, knowledge about the biomechanical behavior of PZCs in various clinical settings is limited. This study was conducted to evaluate the biomechanical behavior of PZCs in different clinical settings using 3-dimensional finite element analysis.
METHODS
3-dimensional models of the PZC, cement, and tooth with six different conditions were simulated in primary molar teeth, incorporating cement thickness (100, 500, and 1000 μm) and cement type (resin-modified glass ionomer cement and resin cement). A total of 200 N of occlusal force was applied to the models, both vertically and obliquely as representative cases. A general linear model univariate analysis with partial eta-squared (ηp) was performed to evaluate the relative effects of the variables.
RESULTS
The overall stress of tooth was increased as the cement space increases under oblique loading. The von Mises stress values of the resin cements were significantly higher than those of the resin-modified glass ionomer cements for all cement thicknesses (p < .05). The effect size of the cement type (η = .519) was more dominant than the cement thickness (η = .132) in the cement layer.
CONCLUSIONS
Within the limits of this study, cement type has a greater influence on the biomechanical behavior of PZCs than cement thickness.
Topics: Humans; Child; Finite Element Analysis; Tooth Preparation; Dental Cements; Glass Ionomer Cements; Dental Materials; Resin Cements; Crowns
PubMed: 36456927
DOI: 10.1186/s12903-022-02596-2 -
Brazilian Dental Journal 2023This study evaluated the effect of toothbrushing on enamel-cementing material-ceramic bonded interfaces, using different cementing materials.
UNLABELLED
This study evaluated the effect of toothbrushing on enamel-cementing material-ceramic bonded interfaces, using different cementing materials.
MATERIALS AND METHODS
Thirty enamel and thirty ceramic blocks were bonded with cementing materials to produce the samples that were bonded with three types of cementing materials: 1- RelyX Ultimate resin cement (REXU), 2- RelyX Unicem 2 self-adhesive resin cement (REU2) and 3- heated Z100 restorative composite (60°C). Bonded interfaces of the samples were toothbrushed and the surfaces of the 3 cementing materials were evaluated for roughness (RG, in µm), roughness profile (RP, in µm), and volume loss (VL, in µm3) (baseline and after 20,000 and 60,000 toothbrushing cycles). Data were evaluated by Generalized Linear Analysis (two factors: "material" and "toothbrushing cycle") and Bonferroni test (α=0.05).
RESULTS
REXU and Z100 exhibited lower RG than that presented by REU2, except after 60,000 toothbrushing cycles when only Z100 differed from REU2. The increase in toothbrushing cycles increased the RG and RP for all materials. REU2 also showed higher RP than those showed by REXU and Z100 when it was analyzed regarding the enamel. The VL of Z100 was the lowest with 20,000 toothbrushing cycles, regarding the enamel and ceramic. For 60,000 cycles, REXU showed the lowest VL regarding the ceramic, and REU2 had the highest VL regarding the enamel and ceramic.
CONCLUSION
In general, REXU and Z100 showed the best results regarding the evaluations performed and the REU2 exhibited the highest RG, RP, and VL.
Topics: Resin Cements; Toothbrushing; Dental Porcelain; Composite Resins; Dental Cements; Glass Ionomer Cements; Ceramics; Dental Enamel; Surface Properties; Materials Testing
PubMed: 38133474
DOI: 10.1590/0103-6440202305459 -
Dental Materials : Official Publication... Jan 2019The addition of charged polymers, like poly-aspartic acid (pAsp), to mineralizing solutions allows for transport of calcium and phosphate ions into the lumen of collagen...
UNLABELLED
The addition of charged polymers, like poly-aspartic acid (pAsp), to mineralizing solutions allows for transport of calcium and phosphate ions into the lumen of collagen fibrils and subsequent crystallization of oriented apatite crystals by the so-called Polymer-Induced Liquid Precursor (PILP) mineralization process, leading to the functional recovery of artificial dentin lesions by intrafibrillar mineralization of collagen.
OBJECTIVE
To evaluate the feasibility of applying the PILP method as part of a restorative treatment and test for effectiveness to functionally remineralize artificial lesions in dentin.
MATERIALS AND METHODS
Two methods of providing pAsp to standardized artificial lesions during a restorative procedure were applied: (A) pAsp was mixed into commercial RMGI (resin modified glass ionomer) cement formulations and (B) pAsp was added at high concentration (25mg/ml) in solution to rehydrate lesions before restoring with a RMGI cement. All specimens were immersed in simulated body fluid for two weeks to allow for remineralization and then analyzed for dehydration shrinkage, integrity of cement-dentin interface, degree of mineralization, and changes in the nanomechanical profile (E-modulus) across the lesion.
RESULTS
After the remineralization treatment, lesion shrinkage was significantly reduced for all treatment groups compared to demineralized samples. Pores developed in RMGI when pAsp was added. A thin layer at the dentin-cement interface, rich in polymer formed possibly from a reaction between pAsp and the RMGI. When analyzed by SEM under vacuum, most lesions delaminated from the cement interface. EDS-analysis showed some but not full recovery of calcium and phosphorous levels for treatment groups that involved pAsp. Nanoindentations placed across the interface indicated improvement for RMGI containing 40% pAsp, and were significantly elevated when lesions were rehydrated with pAsp before being restored with RMGI. In particular the most demineralized outer zone recovered substantially in the elastic modulus, suggesting that functional remineralization has been initiated by pAsp delivery upon rehydration of air-dried demineralized dentin. In contrast, the effectiveness of the RMGI on functional remineralization of dentin was minimal when pAsp was absent.
SIGNIFICANCE
Incorporation of pAsp into restorative treatments using RMGIs promises to be a feasible way to induce the PILP-mineralization process in a clinical setting and to repair the structure and properties of dentin damaged by the caries process.
Topics: Apatites; Dental Caries; Dental Cements; Dentin; Glass Ionomer Cements; Humans
PubMed: 30545611
DOI: 10.1016/j.dental.2018.11.030 -
Brazilian Dental Journal 2022This study was aimed to evaluate the fit of occlusal veneer restoration for two CAD/CAM materials with different cement space settings, using microCT scans. Sixty resin...
This study was aimed to evaluate the fit of occlusal veneer restoration for two CAD/CAM materials with different cement space settings, using microCT scans. Sixty resin dies were made and divided into two groups (n=30) according to the materials, (I): Hybrid all-ceramic, and (II): zirconia-reinforced lithium silicate glass-ceramic. Each group was subdivided into three subgroups (n=10) according to the cement space parameters (30, 40, and 50 µm). Occlusal veneers for the six subgroups were milled. A circle with 20 different sections was placed at the center of every scanned specimen to measure four different locations (Occlusal, Axial, Marginal, and Absolute marginal discrepancy). Data were analyzed using two-way ANOVA at a 0.05 level of significance. There was no statistically significant effect of material type on the mean values of internal and marginal gaps for the three cement space parameters (P>0.05). There were no statistically significant differences in the occlusal and axial gap between the cement space parameters, furthermore, there were statistically significant differences in marginal gap distances and absolute marginal discrepancies (P>0.05). Hybrid all-ceramic showed smaller marginal and internal discrepancies than zirconia-reinforced lithium silicate glass-ceramic without statistically significant differences, and, for both materials, 50 µm cement space significantly improved the marginal fit and absolute marginal discrepancy.
Topics: Ceramics; Computer-Aided Design; Crowns; Dental Cements; Dental Marginal Adaptation; Dental Materials; Dental Porcelain; Dental Prosthesis Design; Glass Ionomer Cements; Lithium; Materials Testing; X-Ray Microtomography
PubMed: 36043571
DOI: 10.1590/0103-6440202204764 -
Dental Materials Journal Dec 2019The aim of this in vitro study was to explore light transmission through an individually formed fiber-reinforced composite (FRC) post compared with two prefabricated FRC...
The aim of this in vitro study was to explore light transmission through an individually formed fiber-reinforced composite (FRC) post compared with two prefabricated FRC posts. Three different glass FRC posts from different manufacturers were used: two groups included prefabricated glass FRC posts (RelyX and GC Fiber Posts) and one group consisted of individually formed E-glass FRC posts with semi-interpenetrating polymer network (semi-IPN) polymer matrix (everStick Post). Various lengths of posts and lightprotected cylinders were made. The specimens were light-polymerized on the test tray of a light radiance testing device (MARC Resin Calibrator). Light transmission in the direction of fibers was registered. Light transmission decreased with increasing post length (p≤0.001; ANOVA) up to 12 mm in all post groups. The individually formed FRC post showed highest light transmission in all cylinder lengths (p<0.001) compared to prefabricated FRC posts, which could benefit polymerization of post material and luting cement.
Topics: Composite Resins; Dental Cements; Dental Stress Analysis; Glass; Materials Testing; Post and Core Technique; Resin Cements
PubMed: 31406094
DOI: 10.4012/dmj.2018-217 -
Australian Dental Journal Mar 2022Fluoride has been shown to be an effective agent in the prevention of caries during orthodontic treatment. Resin-modified glass-ionomer cements possess therapeutic... (Review)
Review
Fluoride has been shown to be an effective agent in the prevention of caries during orthodontic treatment. Resin-modified glass-ionomer cements possess therapeutic anticariogenic properties acting as a fluoride reservoir and releasing fluoride into the environment, particularly at low pH where there is a threat of enamel demineralisation and white spot lesions (WSL's). Patient compliance to instructions in standard oral hygiene measures limits the success of caries prevention and the routine use of glass-ionomer cements can mitigate the lack of compliance, although RMGIC's are not a panacea against WSL's. The adhesion of GIC's to the enamel surface is a physicochemical bond rather than a mechanical bond which reduces the risk of iatrogenic damage to the enamel when bonding and debonding attachments. RMGIC's can be recommended as a bonding adhesive for all attachments but one needs to be selective when bonding molar attachments to avoid occlusal interferences as masticatory forces can be high in these areas.
Topics: Composite Resins; Dental Bonding; Dental Caries; Dental Cements; Fluorides; Glass Ionomer Cements; Humans; Orthodontic Brackets; Resin Cements
PubMed: 34762310
DOI: 10.1111/adj.12888