Partial caries removal may have advantages but limited evidence on restoration survival

Comparison of remineralization ability of tricalcium silicate and of glass ionomer cement on residual dentin: an in vitro study

OBJECTIVE

This study aimed to compare the remineralization effects of a calcium silicate-based cement (Biodentine) and of a glass ionomer cement (GIC: Fuji IX) on artificially demineralized dentin.

METHODS

Four standard cavities were prepared in dentin discs prepared from 34 extracted sound human third molars. In each disc, one cavity was covered with an acid-resistant varnish before demineralization (Group 1). The specimens were soaked in a chemical demineralization solution for 96 h to induce artificial carious lesions. Thereafter, one cavity each was filled with Biodentine (Group 2) and GIC (Group 3), respectively, and one carious lesion was left unrestored as a negative control (Group 4). Next, specimens were immersed in simulated body fluid (SBF) for 21 days. After cross-sectioning the specimens, the Ca/P ratio was calculated in each specimen by using scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDX). Finally, data were analyzed using repeated-measures ANOVA with post-hoc Bonferroni correction.

RESULTS

Both cement types induced dentin remineralization as compared to Group 4. The Ca/P ratio was significantly higher in Group 2 than in Group 3 (p < 0.05).

CONCLUSION

The dentin lesion remineralization capability of Biodentine is higher than that of GIC, suggesting the usefulness of the former as a bioactive dentin replacement material.

CLINICAL RELEVANCE

Biodentine has a higher remineralization ability than that of GIC for carious dentin, and its interfacial properties make it a promising bioactive dentin restorative material.

Current Strategies to Control Recurrent and Residual Caries with Resin Composite Restorations: Operator- and Material-Related Factors

This review addresses the rationale of recurrent and/or residual caries associated with resin composite restorations alongside current strategies and evidence-based recommendations to arrest residual caries and restrain recurrent caries. The PubMed and MEDLINE databases were searched for composite-associated recurrent/residual caries focusing on predisposing factors related to materials and operator’s skills; patient-related factors were out of scope. Recurrent caries and fractures are the main reasons for the failure of resin composites. Recurrent and residual caries are evaluated differently with no exact distinguishment, especially for wall lesions. Recurrent caries correlates to patient factors, the operator’s skills of cavity preparation, and material selection and insertion. Material-related factors are significant. Strong evidence validates the minimally invasive management of deep caries, with concerns regarding residual infected dentin. Promising technologies promote resin composites with antibacterial and remineralizing potentials. Insertion techniques influence adaptation, marginal seal, and proximal contact tightness. A reliable diagnostic method for recurrent or residual caries is urgently required. Ongoing endeavors cannot eliminate recurrent caries or precisely validate residual caries. The operator’s responsibility to precisely diagnose original caries and remaining tooth structure, consider oral environmental conditions, accurately prepare cavities, and select and apply restorative materials are integral aspects. Recurrent caries around composites requires a triad of attention where the operator’s skills are cornerstones.

Interfacial Bond Strength and Morphology of Sound and Caries-affected Dentin Surfaces Bonded to Two Resin-modified Glass Ionomer Cements

OBJECTIVE

To evaluate the shear bond strength and interfacial morphology of sound and caries-affected dentin (CAD) bonded to two resin-modified glass ionomer cements (RMGICs) after 24 hours and two months of storage in simulated body fluid at 37°C.

METHODS AND MATERIALS

Sixty-four permanent human mandibular first molars (32 sound and 32 with occlusal caries, following the International Caries Detection and Assessment System) were selected. Each prepared substrate (sound and CAD) was conditioned (10% polyacrylic acid) and bonded to Activa BioACTIVE Restorative (Activa) and Fuji II LC (F2LC) as per the manufacturers' instructions. Shear bond strength (SBS) was performed after 24 hours and two months of storage. The interfacial surfaces were examined using a digital microscope and scanning electron microscope (SEM). Three-way ANOVA, Bonferroni post-hoc tests (α=0.05), and independent T-tests were used for multifactorial analysis.

RESULTS

Activa exhibited reduced bond strength values to sound and CAD in comparison to F2LC after two time periods (p=0.01). There is a pronounced enhancement in SBS of F2LC when bonded to CAD (p=0.01) after storage, with no statistically significant effect on sound dentin (p=0.309). Activa showed stable SBS to sound and CAD immediately and post-aging (p>0.05). However, the evidence of mineral-like deposits under an SEM attached to the aged, debonded dentin surfaces, thereby obliterating the exposed dentinal tubules, might support the tissue repair potential of Activa.

CONCLUSIONS

The SBS of Activa was lower than F2LC when bonded to sound and CAD, but the bonding stability and sealing ability is advantageous in minimally invasive therapy, suggesting use with a resin composite coverage when used in stress-bearing areas.

Fracture resistance of extensive bulk-fill composite restorations after selective caries removal

This study evaluated the effect of selective carious tissue removal on the fracture strength and failure mode of composite restorations in molars presenting only the buccal cusps. Deep cavities were prepared on the occlusal surface, and the lingual cusps were removed. Carious lesions in the middle of the pulpal wall were artificially induced with acetic acid (pH = 4.5) for 35 days. The demineralized dentin was left intact or was completely removed prior to restoration with a bulk-fill composite (n = 10). Images of the specimens were obtained by optical coherence tomography (OCT) before and after the caries induction/removal. The mechanical resistance to fracture by axial compressive loading and the failure type and extension were determined. The pulpal wall/composite interface of the fractured specimens was analyzed by OCT. The data were analyzed for significance with t-tests (α = 0.05). The deepest cavities and a more frequent occurrence of pulpal exposure were observed more often for non-selective carious tissue removal. The protocol of carious tissue removal did not affect the fracture strength (p = 0.554). An increased occurrence of catastrophic failures involving the roots was observed for non-selective carious tissue removal. Some occurrences of restoration displacement or cracks throughout the resin-dentin were observed only for the selective carious tissue approach. Selective carious tissue removal is a feasible approach to extensively damaged teeth since it reduced the occurrence of pulpal exposure and root fractures, without compromising the fracture strength.

Efficacy of CO lasers in preventing dental caries in partially erupted first permanent molars: a randomized 18-month clinical trial

The aim of this controlled randomized double-blinded clinical trial was to evaluate the use of a CO₂ laser with or without topical application of acidulated fluorides in the prevention of dental caries in partially erupted first permanent molars. We selected 61 healthy children at high risk of caries, all between 6 and 8 (7.1 ± 0.8) years of age and with 4 partially erupted first permanent molars. A CO₂ laser device emitting at 10.6 μm was used (0.5 W, 0.05 mJ per pulse, 10 kHz). Each first molar in an individual was randomly assigned to one treatment: (L) CO₂ laser (0.066 J/cm²); (FL) 1.23% acidulated fluoride gel and CO₂ laser (0.066 J/cm²); (V) 5% fluoride varnish, or (S) sealant (control). Patients were followed-up at 3, 6, 12, and 18 months after treatment, through direct visual examination and by an operator blinded to the treatments (kappa ≥ 0.70). The International Caries Detection and Assessment System (ICDAS-II) index was used to assess the soundness of tooth structure or the presence of white spot lesions, cavitated enamel, and/or dentin lesions. The Yildiz Visual Index was used to evaluate sealant retention. Results were evaluated using Kaplan-Meier survival analysis, and the hazard ratio of the treatments was estimated using shared frailty models with a gamma distribution, which considered the patient as a cluster. There were no significant differences among treatments compared to sealants. After 18 months, the use of a CO₂ laser with or without acidulated fluorides was shown to be effective in preventing caries on the occlusal surface of partially erupted permanent first molars in children at high risk for caries.

Evaluation of Dentin-Pulp Complex Response after Conservative Clinical Procedures in Primary Teeth

Introduction

Although selective caries tissue removal decreases the number and diversity of bacteria, stops the caries process, and reduces the risk of pulp exposure, the studies on the minimally removal of caries tissue are limited and further clinical research is necessary in this field.

Aim

This study aimed to evaluate through clinical and radiographic assessments the in vivo response of the dentin-pulp complex of human deciduous teeth after either partial or total caries removal (TCR).

Materials and methods

A total of 49 deciduous molars of children aged between 5 and 9 years were carefully selected. The teeth were divided into two groups: Group I: Partial removal of caries; group II: Total removal of caries. Clinical and radiographic evaluations were performed during the period of 4 to 6 months after the procedure. The intraexam-iner reproducibility was determined by Kappa test. Fisher’s exact test was used to determine the statistical difference between groups.

Results

All teeth showed clinical success during the 4- to 6-month evaluation period. The radiographic evaluation showed 94.2 and 89.6% of success rate in groups I and II respectively. Radiographic results did not show statistically significant differences between the studied groups (p > 0.05).

Conclusion

The partial caries removal (PCR) showed satisfactory clinical and radiographic outcomes, suggesting that this minimally invasive approach might replace the TCR when correctly indicated.

How to cite this article: Mello B, Stafuzza TC, Vitor L, Rios D, Silva T, Machado M, Oliveira TM. Evaluation of Dentin-Pulp Complex Response after Conservative Clinical Procedures in Primary Teeth. Int J Clin Pediatr Dent 2018;11(3):188-192.

Retrospective analysis of factors associated with the success of stepwise excavation procedure in deep carious lesions

BACKGROUND

Recent scientific evidence regarding the stepwise excavation procedure (SWP) has not addressed the consideration of patient factors when selecting SWP as treatment for deep carious lesions (DCLs). This study assessed patient factors predicting a successful SWP defined as a tooth restored with SWP and did not result in root canal treatment or a dental extraction.

METHODS

SWPs completed in 626 patients without symptomatic irreversible pulpitis at the University of Iowa College of Dentistry from January 2004 through December 2012 were evaluated. Patient demographic and tooth-specific characteristics were assessed in their relationship with the main outcome.

RESULTS

SWPs had a 75% success rate when evaluated within 36 months of the initial treatment. Findings showed that patients who had successful SWP treatment of DCLs were somewhat younger than patients whose SWP treatment was not successful (mean age, 37.4 years and 40.5 years, respectively; odds ratio, 0.981; 95% confidence interval, 0.967 to 0.994; P = .0058). Patients who returned to their second appointment within 5 to 9 months were more likely to have a successful SWP treatment than those returning sooner than 5 months (odds ratio, 0.338; 95% confidence interval, 0.210 to 0.545; p < .0001).

CONCLUSION

Treatment of deep carious lesions with SWP is effective for pulp preservation and patient age may influence the outcome.

PRACTICAL IMPLICATIONS

Although a somewhat younger mean patient age was associated with successful treatment of DCLs, SWP can be successful regardless of patient age and clinicians should consider SWP in treating DCLs.

Alternative approach for carious tissue removal in primary teeth

BACKGROUND

Minimally-invasive techniques for the management of carious dental tissue has been well documented. This study aimed to report on the clinical and radiographic response after partial caries removal on left mandibular primary second molar.

CASE REPORT

A 6-year-old boy sought treatment because of pain in the left mandibular primary second molar. The tooth had a deep caries lesion on the occlusal surface, with loss of enamel structure and dentine proximity with the pulp confirmed by periapical radiograph. According to the clinical and radiographic diagnosis, partial caries removal was the treatment of choice. Calcium hydroxide cement was used as pulp capping material.

FOLLOW-UP

In this case report, partial caries removal showed satisfactory clinical and radiographic outcomes after 18-month following-up period.

CONCLUSION

Partial caries removal only is applicable when properly indicated. However, further clinical studies with longer following-up periods are necessary.

Effect of chemomechanical caries removal on bonding of resin-modified glass ionomer cement adhesives to caries-affected dentine

BACKGROUND

This study evaluated the effect of: (1) chemomechanical caries removal (CMCR); (2) dentine surface treatments and (3) dentine substrates on adhesion of resin-modified glass ionomer cement (RMGIC) adhesives.

METHODS

One hundred and twenty permanent molars exhibiting moderate cavitation on the occlusal surface into dentine were used. Seventy-five carious molars were used for bond strength testing; the remaining 45 for micromorphological evaluation of the bonded interface. Caries was excavated with NaOCl-based CMCR (Carisolv), enzyme-based CMCR (Papacarie), or conventional rotary caries removal methods. Dentine surface treatment was performed using 37% phosphoric acid, 25-30% PAA or 20% PAA + 3% AlCl3 .

RESULTS

Three-way ANOVA revealed that all three factors 'caries removal methods', 'dentine surface treatments' and 'dentine substrates' did not significantly affect bond strength (p > 0.05). Scanning electron microscopy micrographs showed that the acid-base resistant layer was thicker in caries-affected dentine compared to sound dentine.

CONCLUSIONS

NaOCl- and enzyme-based CMCR methods have no adverse effect on adhesion of RMGIC adhesives to sound and caries-affected dentine. Dentine surface treatment with 37% phosphoric acid for 5 s has no negative effect on bonding of RMGIC adhesives to dentine compared with using polyacrylic acid for 10 s. RMGIC adhesives bonded well to both sound and caries-affected dentine.