In vitro Evaluation of Stainless Steel Crowns cemented with Resin-modified Glass Ionomer and Two New Self-adhesive Resin Cements

Retention of Pediatric BioFlx Crowns Versus Stainless Steel Crowns Using Different Types of Luting Cements: An In Vitro Study

BioFlx crowns (BFCs) have been introduced in the dental market, combining the flexibility of stainless steel crowns (SSCs) with the esthetic appeal of preformed zirconia crowns. However, the existing literature does not provide adequate insights regarding the retentive strength of various types of luting cement with these newly developed BFCs. Therefore, this study aimed to evaluate and compare the retentive strength of BFCs and SSCs with different types of luting cement (glass ionomer cement [GIC], resin-modified glass ionomer cement [RMGIC], self-adhesive resin cement [SARC], and polycarboxylate cement [PXC]). A total of 160 standardized resin dies were fabricated and divided into two groups based on the type of crown (BFCs or SSCs). Each group was further subdivided into four subgroups (20/group) based on the luting cement used for cementing the crown on the die. A pullout test was performed using a universal testing machine to measure the retentive strength required for crown dislodgement. The residual cement in the crown was scored to determine the cement failure pattern. Data were analyzed using two-way analyses of variance (ANOVAs) to evaluate the interaction between the cement and the type of crown on retentive strength, followed by an independent t-test. Furthermore, Welch's ANOVA and Dunnett's T3 test were used to assess the impact of various types of luting cement on the retentive strength of each crown. The CFP was assessed by comparing the scores using descriptive statistics. Statistical significance was set at p < 0.05. The mean retentive strength of SSCs and BFCs was the highest with SARC (560.29 ± 8.74 N; 657.72 ± 20.60 N), followed by RMGIC (534.20 ± 22.84 N; 454.90 ± 7.95 N) and GIC (435.14 ± 8.66 N; 237.68 ± 9.37 N), while the lowest was with PXC (365.67 ± 19.11 N; 131.26 ± 5.37 N). A significant difference in retention was observed between the crowns (p < 0.05). Cement failure primarily manifested as adhesive failures in the SARC and RMGIC groups; however, both adhesive and cohesive failures occurred in the GIC and PXC groups. Thus, SSCs demonstrate significantly higher retention than BFCs across all types of luting cements, except when using SARC. Within the limitations of this in vitro study, SSCs emerge as the preferred choice for full-coverage restorations that require optimal retention and durability. Nevertheless, BFCs with SARC provide a viable alternative when esthetic considerations are prioritized.

Evaluation of the shear bond strength of surface-treated cobalt-chromium metal crowns on Corticobasal® implant abutments cemented using different luting agents

PURPOSE

This in-vitro study aimed to compare the shear bond strength (SBS) of cobalt-chromium (Co-Cr) crowns on Corticobasal® implant abutments, evaluating the effects of two surface treatments and two luting agents.

MATERIALS AND METHODS

Thirty Co-Cr crowns were fabricated using CAD-CAM technology with a direct metal laser sintering process and divided into three groups based on surface treatment: Group I (untreated), Group II (sandblasted with 50 μm Al₂O₃), and Group III (Er: YAG laser etching). Each group was further subdivided based on luting cement: Sub group A (GC Fuji Plus) and Sub group B (Rely X U200). This resulted in a total of six groups. The implants were stabilized in auto-polymerizing acrylic resin, and cementation followed standardized protocols. Thermocycling with 1000 cycles (5 °C-55 °C) simulated oral conditions. SBS was tested using a universal testing machine at a crosshead speed of 1 mm/min. Failure patterns were analyzed using stereomicroscopy to classify adhesive, cohesive, and mixed failures. Statistical analysis was performed using one-way ANOVA and Bonferroni post-hoc tests (p < 0.05).

RESULTS

Group IIIA (laser-treated, GC Fuji Plus) showed the highest SBS (243.15 MPa), followed by Group IIA (sandblasted + GC Fuji Plus), at 231.81 MPa. The lowest SBS was observed in Group IB (untreated, Rely X U200) at 124.24 MPa. Both sandblasting and laser treatment significantly enhanced SBS, with GC Fuji Plus consistently outperforming Rely X U200. A significant difference of 48.17 MPa was observed between laser-treated Groups IIIA and IIIB (p < 0.01).

CONCLUSION

Laser etching and GC Fuji Plus cementation provided the highest SBS for Co-Cr crowns on Corticobasal® implants. Sandblasting was a secondary effective treatment, while untreated crowns exhibited the weakest bond strength.

An In Vitro Evaluation of Mechanical Properties of a New Dual-cure, Universal, Bioactive Luting Cement

Aim and background

The aim of this study was to determine the properties of a new luting cement, BioCem®, by evaluating shear bond strength (SBS) and flexural strength (FS).

Materials and methods

A total of 60 extracted deciduous molars were included in this study. Samples were divided into two groups: Group I, Fuji I® (n = 30), and group II, BioCem® (n = 30). Each tooth was embedded in one acrylic block, such that the flattened enamel surface was exposed. Cylinders of 6 mm diameter and 8 mm height were prepared and evaluated for SBS using a universal testing machine. Ten rods of 25 × 2 × 2 mm of each material were prepared using a custom mold to evaluate the FS using a universal testing machine. Statistical Package for the Social Sciences (SPSS) version 20.0 was used for statistical analyses. Intergroup analysis was performed using an independent sample t-test.

Results

Upon comparing the SBS values of the luting agents and prepared enamel surfaces, glass ionomer cement (GIC) displayed the highest value, while BioCem® displayed the lowest. Upon comparing the FS values of the luting agents and prepared enamel surfaces, BioCem® performed better than GIC.

Conclusion

BioCem® may be used as a luting agent for the cementation of stainless steel crowns (SSCs) on primary teeth.

Clinical significance

BioCem®, a recently developed luting cement, may be used for cementing SSCs to the surfaces of prepared deciduous teeth; it exhibits significantly higher FS but lower SBS than that of GIC.

How to cite this article

Shams SA, Nekkanti S, Shetty S. An In Vitro Evaluation of Mechanical Properties of a New Dual-cure, Universal, Bioactive Luting Cement. Int J Clin Pediatr Dent 2024;17(8):887-891.

The stress distribution of a primary molar tooth restored with stainless steel crown using different luting cements

BACKGROUND

The aim of this study is to evaluate the stress distributions of a primary molar tooth restored with a stainless steel crown (SSC) using resin and glass ionomer luting cements by Finite Element Analysis (FEA).

METHODS

Original DICOM data of a primary molar was used to create a 3D model. One model was prepared as a tooth model with SSC. A 30 μm cement layer was used in model. Two different luting cements were tested in the study: self-cure adhesive resin cement, and glass ionomer cement. Vertical and oblique loads of 330 N were applied to simulate maximum bite force and lateral forces in the occlusal contact areas of the models. Maximum von Mises stress values in the models were evaluated as MPa.

RESULTS

The maximum von Mises stress value was observed in the force application and general occlusal contact areas for all models. The maximum von Mises stress values were higher in the tooth model with SSC using self-cure adhesive resin cement (478.09 MPa and 214.62 MPa) than in the tooth model with SSC using glass ionomer cement (220.06 MPa and 198.72 MPa) in both vertical and oblique loading, respectively.

CONCLUSIONS

Depending on the magnitude of the bite force on the SSC, fracture of the luting cement materials could occur if the stress exceeds the endurance limit of the luting cement. Cementation with glass ionomer cement may help to reduce stress levels in SSC restorations of primary molars in children.

The Effect of Dentine Desensitizing Agents on the Retention of Cemented Fixed Dental Prostheses: A Systematic Review

Background and Objectives: The use of desensitizing agents (DA) after tooth preparation to prevent hypersensitivity is well documented in the literature. A fixed dental prosthesis (FDP) should have good retention to be successful. Inadequate retention may result in microleakage, secondary caries, and, eventually, dislodgement of the FDP. The effect of DAs on the retention of FDPs has been widely studied in the literature, but the results are conflicting. Thus, this study aimed to conduct a systematic review to assess the effect of dentine desensitizing agents, used to prevent post-cementation hypersensitivity, on the retention of cemented FDPs. The null hypothesis framed was that there is no effect of dentine desensitizing agents on the retention of cemented FDPs. The focused PICO question was as follows: “Does the application of dentine desensitizing agents (I) affect the retention (O) of cemented fixed dental prosthesis (P) when compared to non-dentine desensitizing groups (C)”? Materials and Methods: Four electronic databases were systematically searched and, on the basis of the predefined inclusion and exclusion criteria, 23 articles were included in this systematic review. A modified CONSORT scale for in vitro studies was used to assess the quality of the selected studies, as all included studies were in vitro studies. Results: Most of the studies compared the effect of more than one type of DA on retention. The results of the selected studies varied due to differences in the composition of tested dentine DAs and types of luting cements. Conclusions: Within the limitations of this study, it can be concluded that the retention values of FDPs cemented using zinc phosphate cement were reduced with most of the DAs, whereas retention values increased when GIC, resin-modified GIC, and resin cements were used with the majority of DAs. These findings are important, as they can guide dentists in selecting the DA before cementing the crowns with the luting agent of their choice, without compromising the retention of the crowns.

Reconstruction of Pulpotomized Primary Molar and Retention of Stainless-steel Crowns: An In-vitro Study

Background:

Stainless steel crowns are proposed to restore severely decayed teeth in pediatric dentistry. Yet, their retention is still debatable.

Objective:

This study aimed to investigate whether dental tissue reconstruction before placement of stainless steel crown on pulpotomized first primary molar affects the retention of stainless steel crowns.

Methods:

This experimental in-vitro study was performed on 30 extracted first primary molars with carious occlusal and distal surfaces. Dental caries and the pulp chamber roof were respectively removed. The stainless steel crowns were placed after tooth preparation. The samples were randomly divided into two groups (n=15) i.e, ZoE core buildup, and ZoE liner. Stainless steel crowns were cemented with self-curing glass ionomer cement. The crown retention was tested with the Instron testing machine. The two groups were compared by using SPSS software through the t-test (α=0.05).

Results:

The mean crown retention in the liner group (291.45±43.196 N) was significantly higher than that of the core buildup group (202.00±63.515 N) (P=0.001).

Conclusion:

Based on the results of this study for restoring the teeth with extensive tissue loss by SSC, ZoE should be used as lining without a core on teeth.

Retentive strength of luting cements for stainless steel crowns: A systematic review

BACKGROUND

Stainless steel crowns (SSCs) are unique coronal restorative materials used commonly in the management of primary teeth with extensive caries.

AIM

The aim of this study was to perform a systematic review to evaluate the retentive strength of luting cements for SSCs.

MATERIALS AND METHODS

Two reviewers performed a database search of the studies published from 2004 till date. The inclusion criteria were papers published in the English language andin vitro studies on retentive strength of SSC on primary molars. All potentially relevant studies were identified by the title and the abstract. After the full-text analysis, the selected studies were included in the systematic review.

RESULTS

Sixteen nonduplicated studies were found. However, after reviewing the articles, only seven were included. Risk bias was assessed. Out of seven studies included in the systematic review, five studies presented medium risk of bias and two studies showed high risk of bias.

CONCLUSION

Within the limitations of this study, thein vitro literature seems to suggest that the use of self-adhesive resin cements shows higher retentive strength, followed by resin-modified glass-ionomer cement (RM-GIC) and conventional GIC. However, RM-GIC can be a preferred luting agent due to its clinical advantages over resin cements. Thus, it can be concluded that choice of cement will depend on individual patient needs and clinical situation.

Comparative Evaluation of Physical and Mechanical Properties of Different Brands of Primary Molar Stainless-Steel Crowns: An In Vitro Study

BACKGROUND

There is some cases of perforation and undesirable properties of some primary molars stainless steel crowns.

AIM

The aim of this study was to compare the physical and mechanical properties of different commercial brands of these crowns.

METHODS

In an in vitro study, 10 stainless steel tooth crowns of the second primary mandibular molars size 6 of 4 different commercial brands (a total of 280 crowns) were evaluated. These crowns were included KTR Pre-trimmed and Crimped Nichro Stainless Steel Primary Molar Crowns (KTR, China); 3M Stainless Steel Primary Molar Crowns (ESPE, St paul; USA); NuSmile SSC Pre-contoured (Inc, Houstone, TX; USA) and Kids crown (Shinghung, Seoul; Korea). Corrosion and galvanic corrosion, wear, microhardness, compressive strength, fatigue strength of crowns and weight percent of elements were investigated.

RESULTS

The highest rate of microhardness, compressive and Fatigue strength of the crowns were made by Nu Smile > 3M > Kids Crown > KTR respectively. The highest rate of corrosion potential in corrosion and Galvanic corrosion tests was in KTR > Kids crowns > 3M > Nu smile respectively. The order of crown wear was KTR > Kids Crown > 3M > Nu Smile respectively. The highest amount of nickel element was found in the Nu Smile crown and the highest amount of chrome in the 3M crown with a significant difference with others (p < 0.001). The KTR and Kids crowns lacked molybdenum.

CONCLUSION

The results showed that Nu Smile crown has better physical and mechanical properties than other evaluated crowns in this study.

Influence of Polishing Methods on the Bonding Effectiveness and Durability of Different Resin Cements to Dentin

The purpose of this study was to investigate the impact of polishing methods on the bonding effectiveness and durability of different resin cements to dentin. The dentin surfaces were either treated with a fine-grit diamond bur (polishing A) or further polished by polishing disks (polishing B), and then they were bonded with any one of the three resin cements, namely, etch-and-rinse, self-etch, and self-adhesive resin cements. After 24-hour or 2-year water storage, a microtensile bond strength (μTBS) test was performed. A scanning electron microscope (SEM) was used to observe the morphology of the smear layer as well as the resin-dentin bonding interface. The results indicated that a thinner smear layer thickness was created by polishing B compared with polishing A. Although self-etch and self-adhesive resin cements achieved a relatively high primary bond strength before water degradation, etch-and-rinse resin cement obtained a stable bond strength during water degradation. The application of an additional polishing procedure could improve the bond strength of self-etch and self-adhesive resin cements.

Effect of a filled adhesive as the desensitizer on bond strength of "Self-Adhesive Cements To" differently severity of fluorosed dentin

The objectives were to evaluate the efficacy of a filled adhesive named Prime & Bond NT (P&B NT) as the dentin desensitizer in occluding fluorosis dentinal tubules and compare the shear bond strength (SBS) of RelyX U200 self-adhesive resin cement (RXU) and RelyX Luting self-adhesive resin-modified glass ionomer cement (RMGIC) before and after P&B NT pretreatment. 176 non-carious fluorosis were classified into four subgroups by the Thylstrup and Fejerskov index (TFI): normal group (TFI = 0), mild group (TFI = 1-3), moderate group (TFI = 4-5), severe group (TFI = 6-9). 160 composite cylinders (4 × 5 mm) were fabricated, then every severity of fluorosed dentin was subjected to four treatments: P&B NT + RXU (n = 40), RXU (n = 40), P&B NT + RMGIC (n = 40), RMGIC (n = 40). The specimens were immersed in water at 37°C for 24 hr first and half of them underwent 5,000 thermocycling before shear bond strength test. A factorial design (factorial 4 × 2 × 2 × 2) was developed to make statistical analysis. Scanning electron microscope (SEM) analysis (n = 16) in cross section and longitudinal section view characterized the occlusion situation of dentinal tubules. P&B NT might occlude dentinal tubules as the dentin desensitizer for normal teeth and mild-moderate fluorosis. P&B NT significantly increased the SBS of RXU (p < .05) but had no statistical significance on the SBS of RMGIC (p > .05). RXU could benefit from P&B NT desensitization to achieve a better quality of adhesion.

Evaluation of retentive strength of four luting cements with stainless steel crowns in primary molars: An in vitro study

BACKGROUND

Stainless steel crown (SSC) is the most reliable restoration for primary teeth with extensive caries. Retention is of great importance for a successful restoration and is provided by various factors such as luting cements. The aim of this study was to evaluate the retentive strength of SSC cemented with four different luting cements.

MATERIALS AND METHODS

In this in vitro study, A total of 55 extracted primary first molars were selected. Following crown selection and cementation (one with no cement and four groups cemented with resin, glass ionomer, zinc phosphate, and polycarboxylate), all the specimens were incubated and thermocycled in 5°C-55°C. Retentive properties of SSCs were tested with a mechanical test machine. First dislodgement of each specimen and full crown removal were recorded. One-way ANOVA test followed by least significant difference test and Kruskal-Wallis test was used for retentive strength comparison at the level of significance of P < 0.05.

RESULTS

The results of the study showed that the specimens cemented with zinc phosphate exhibited higher retentive strength as compared to glass ionomer and polycarboxylate (P < 0.001 and P = 0.023, respectively).

CONCLUSION

Zinc phosphate cement showed the most promising results; thus, it can be preferably used for cementation of the teeth with no grossly broken down crowns.