The effect of caries excavation methods on the bond strength of etch-and-rinse and self-etch adhesives to caries affected dentine

Effect of Method of Removing Caries-Affected Dentin on the Bond Strength of Composite Resin to Root Canal Dentin

The adhesion of composite resin to caries-affected dentin differs from the adhesion of resin to sound dentin. We evaluated the bond strengths of dual-cure resin composites applied to caries-affected root canal dentin under various clinical conditions and using several caries removal indicators. In the dye stain 1 group, caries were removed to a pale pink stain level using a caries detector. In the dye stain 2 group, caries were removed to a stain-free level using a caries detector. In the probing group, caries were removed to the level of hardness based on probing with a sharp explorer. Additionally, a sound dentin group was used as a control. We compared the resin composite microtensile bond strengths and failure mode distribution among the groups. The bond strengths (MPa) of the probing (64.6 ± 11.9) and the sound dentin (68.7 ± 11.1) groups were significantly higher than those of the dye stain 1 (46.9 ± 7.9) and 2 (47.5 ± 8.4) groups (p < 0.05). The removal of caries-affected dentin using a dentin-hardness-based technique showed higher tensile strength than that using a dye stain technique involving removal to any color level. Thus, the caries removal technique used on root canal dentin affects the bond strength of the resin composite.

A Bibliometric Analysis (2010-2020) of the Dental Scientific Literature on Chemo-Mechanical Methods of Caries Removal Using Carisolv and BRIX3000

Reports in the literature have proposed and analyzed several minimally invasive techniques for caries removal in recent decades. In light of recent events surrounding the ongoing epidemiological context, concerns have been raised regarding the generation of aerosols during dental procedures. The aim of our research was to provide an overview of the scientific literature on the topic of chemo-mechanical caries removal (CMCR) methods, focusing on two products (Carisolv, BRIX3000), commercially available in Europe. A bibliometric analysis was used to investigate the scientific articles included in Web of Science (WoS) Core Collection database, published from January 2010 to December 2020. We analyzed the co-occurrence of all keywords (Author Keywords and the KeyWords Plus section), co-authorship and co-citation, using the free software VOSviewer. Our bibliometric analysis revealed a worldwide interest in the subject of chemo-mechanical methods of caries removal, which has transcended the area of pediatric dentistry. The analyzed studies have been conducted mainly in high-income countries that have developed sanitary policies regarding prevention and early treatment of carious lesions as a health priority.

Effect of bioceramic root canal sealers on the bond strength of fiber posts cemented with resin cements

This study aimed to evaluate the influence of calcium silicate-based sealers on the bond strength of fiber posts using conventional and self-adhesive resin cement. Sixty single-rooted teeth were selected. The canals were prepared with a reciprocating instrument 40.06. The roots were randomly distributed in six groups (n = 10) according to the strategies for root canal filling and fiber posts cementation: AH Plus/RelyX ARC; AH Plus/RelyX U200; Bio C Sealer/RelyX ARC; Bio C Sealer/RealyX U200; Sealer Plus BC/RelyX ARC; and Sealer Plus BC/RelyX U200. The roots were transversally sectioned, and one slice per post-third was obtained. The push-out test was performed at a crosshead speed of 1mm/min. The failure patterns were described after assessment with a stereomicroscope with a 10× magnification. Bond strength was calculated and analyzed using the ANOVA and Tukey test. AH Plus did not influence the bond strength of fiber posts cemented with conventional (RelyX ARC) or with self-adhesive resin cement (RelyX U200). The lowest bond strength values were obtained when calcium silicate-based sealers were associated with conventional resin cement (Bio C Sealer/RelyX ARC and Sealer Plus BC/RelyX ARC). Except for Sealer Plus BC/RelyX ARC, all groups presented lower bond strength at the apical portion compared to the cervical portion of the post. Adhesive failures between cement and post and cement and dentin were predominant (55.3%). Calcium silicate-based sealers decreased the bond strength of fiber posts cemented with conventional resin cement.

Ultrasound device as a minimally invasive approach for caries dentin removal

Abstract The aim of this study was to evaluate the efficacy of an ultrasound device and the dentin surface morphology after removal of the caries dentin lesions by removal rate and scanning electron microscopy (SEM). The Knoop hardness test on the bovine dentin blocks (n = 20, 4x4x2mm) was performed to standardize the samples and only those with 38 ± 2 KHN were included. The dentin blocks were submitted to induction of artificial caries lesions, using the bacterial model. Strains of Streptococcus mutans and Lactobacillus acidophilus were used for 7 days. The caries dentin lesion was removed for 1 min, according to two methods: G1 - carbide bur under low-speed rotation (control group) and G2 - ultrasound device under refrigeration. For the removal rate, the samples were weighed 3 times: T0 (before induction), T1 (after induction) and T2 (after removal). Morphology evaluation of the residual dentin surface was performed by SEM. Data normality was verified by Shapiro-Wilk test (p ≥ 0.240). T-test for independent samples was applied to evaluate the removal rate. A significance level of 5% was adopted. G2 provided lower removal rate than G1 (G1: 3.68 mg and G2 = 2.26 mg). SEM images showed different morphological characteristics between the groups. G2 showed absent of smear layer, while G1 showed a visible smear layer over the surface. We concluded that ultrasound device provides minimally invasive removal with residual dentin exhibiting open dentin tubules and no smear layer formation and no bacteria, which infer the removal of the infected tissue.

Deproteinization of caries-affected dentin with chemo-mechanical caries removal agents and its effect on dentin bonding with self-etch adhesives

OBJECTIVES

To evaluate the micro-tensile bond strength (μTBS) of self-etch adhesives (SEA) to normal and caries-affected dentin after smear layer deproteinization with papain enzyme-based and NaOCl-based chemo-mechanical caries removal agents (CRAs) and to compare their efficacy to a 6 % NaOCl solution.

METHODS

Forty extracted human molars with occlusal carious lesions were randomly divided into four pretreatment groups: no treatment (control), Papacarie for 60 s, Carisolv for 60 s, and 6 % NaOCl for 15 s. After pretreatment, Universal Bond Quick ER (UBQ, one-step, 1-SEA) or Clearfil SE Bond 2 (CSE, two-step, 2-SEA) was applied to the pre-treated surface, and built-up with resin composite (Clearfil AP-X). The μTBS test was performed after 24 h water storage of the specimens at 37 °C, and the modes of failure were determined under SEM. Deproteinizing effects of the tested agents on smear layer-covered dentin was quantified by changes in the amide:phosphate ratio using attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR) analysis.

RESULTS

On caries-affected dentin the μTBS improved significantly after pretreatment with Papacarie, Carisolv, and 6 % NaOCl with both SEAs (p < 0.05). Papacarie pretreatment significantly improved the μTBS of UBQ on normal dentin compared to NaOCl pretreatment (p < 0.05). ATR-FTIR revealed that all agents significantly decreased the amide:phosphate ratio on the smear layer-covered normal and caries-affected dentin (p < 0.05).

CONCLUSIONS

Smear layer deproteinizing with papain enzyme-based and NaOCl-based gel CRAs was effective in improving the micro-tensile bond strength of self-etch adhesives to caries-affected dentin.

CLINICAL SIGNIFICANCE

Smear layer deproteinization with Papacarie (a papain enzyme-based gel) or Carisolv (a NaOCl-based gel) can improve the μTBS to normal and caries-affected dentin bonded with 2-step self-etch adhesives.

Effect of a Papain-based Chemomechanical Agent on Structure of Dentin and Bond Strength: An in vitro Study

Aim

To evaluate the microtensile bond strength of teeth restored with packable composite after removing caries with three chemomechanical caries removal agents (Carisolv, Papacarie and Carie-care) and also to analyze its effect on chemical composition of dentin using energy-dispersive X-ray (EDX) analysis.

Design

A total of 40 carious molars with 1 to 1.5 mm of remaining dentin were selected and divided into four groups of 20 each. Group I (control)—bur, group II—Carisolv, group III—Papacarie, group IV—Carie-care. A total of 15 samples from each group were restored with composite; 1 mm thick sections were made and were debonded under tensile load. Remaining five samples from each group were subjected to EDX for elemental analysis of dentin surface.

Results

No statistically significant difference in the bond strength values and Ca/P ratio was observed between control group and three chemomechanical agents tested in the study.

Conclusion

None of the chemomechanical agents tested in the study adversely affected the bond strength of composite resin to caries-affected dentin. Therefore, newer papain-based chemomechanical agent Carie-care can be considered as an equally effective economical alternative to commonly used agents Carisolv and Papacarie.

How to cite this article: Nair S, Nadig RR, Pai VS, Gowda Y. Effect of a Papain-based Chemomechanical Agent on Structure of Dentin and Bond Strength: An in vitro Study. Int J Clin Pediatr Dent 2018;11(3):161-166.

Comparative Evaluation of Various Temperature Changes on Stress Distribution in Class II Mesial-occlusal-distal Preparation restored with Different Restorative Materials: A Finite Element Analysis

Introduction

The principal goal of dentistry is to maintain and improve the quality of life of the dental patients. As many of these objectives require the replacement or alterations of the existing tooth structure, the main challenge for centuries has been the development and selection of biocompatible materials that can withstand the unique conditions of the oral environment.

Finite element analysis (FEA) is a modern technique of numerical stress analysis that has become a solution to the task of predicting failure due to unknown stresses by showing problem areas in a material and allowing designers to see all of theoretical stresses within.

Aims and objectives

To evaluate and compare the effect of various temperature changes on the stress distribution, in class II mesial-occlusal-distal (MOD) cavity when restored with different restorative materials, using the finite element method (FEM).

Materials and methods

Using FEA, various thermal stresses generated in class II MOD lesion using different restorative materials were studied.

Results

The computer-generated models of intact tooth and teeth restored with the different restorative materials were designed, and thermal stress at different temperatures was observed when subjected to the thermal loads of 5°C, 20°C, 36°C, and 55°C. From the results of the study, it can be concluded that glass ionomer cement (GIC) performed best, followed by intact tooth, composite resin, silver amalgam, and zinc oxide eugenol cement.

Conclusion

Restoration of class II MOD lesions with materials of lower modulus of elasticity and lower coefficient of thermal expansion will enable better stress distribution.

How to cite this article: Srivastava B, Devi NN, Gupta N, Singh R. Comparative Evaluation of Various Temperature Changes on Stress Distribution in Class II Mesial-occlusal-distal Preparation restored with Different Restorative Materials: A Finite Element Analysis. Int J Clin Pediatr Dent 2018;11(3):167-170.

Pediatric Dental Appointments No-show: Rates and Reasons

Aim

To determine the frequency and reasons of missed and canceled pediatric dental appointments and identifying the factors associated with it among the patients visiting the pediatric dental clinic of the dental college in Navi Mumbai, Maharashtra, India. To assess the parents' perception regarding the treatment of their children and to explore the merit of different management strategies regarding the missed appointments.

Materials and methods

Self-administered questionnaires were handed over to the parents in the waiting area, whose children were undergoing treatment in the pediatric dental clinic. Questionnaire included questions pertaining to the sociodemo-graphic characteristics, methods of remembering appointments, and satisfaction with the overall past clinic experience.

Results

Of the 294 surveyed sample, 52.0% stated that they have missed an appointment. Highest percentage of the patients had missed due to parents' forgetfulness and patient's exams; 52.0% relied on their memory to remember their appointments, and 44.5% used their diaries and mobiles as a means of reminders. For canceling an appointment, most of them stated that patient was unwell and parents' commitments toward other work led to an increase in rates of no-shows. Socioeconomic status and the methods of remembering the appointment date were found to be significantly correlated with missing an appointment among the surveyed sample (p < 0.05); 48.3% said that they would want a call from the dentist a day prior to their appointment as a reminder.

Conclusion

Around one half of the patients attending the pediatric dental clinic missed their appointments. Patients most likely to fail to keep an appointment was the one who was young, remembered appointment via memory, came from a high socioeconomic class, most of them were males, and had previously broken appointments, while patients preferred receiving a call from the dentist as a reminder aide.

Clinical significance

Missing appointment creates a series of problems. Firstly, it deprives another patient the opportunity of getting treated. Secondly, it contributes to the development of long waiting list for dental services. Thirdly, it affects the patient's treatment time and may cause increase in the dental emergencies leading to a disruption in the doctor-patient relationship and behavioral management problems.How to cite this article: Bhatia R, Vora EC, Panda A. Pediatric Dental Appointments No-show: Rates and Reasons. Int J Clin Pediatr Dent 2018;11(3):171-176.