A study of the classification and treatment of noncarious cervical lesions by general practitioners

A qualitative analysis of dentists' understanding and management of non-carious cervical lesions (NCCL)

INTRODUCTION

Non-carious cervical lesions (NCCLs) are considered to have a multi-factorial aetiology and their management is affected by a range of variables perhaps most importantly clinical judgement. The aim of this study was to elicit information from practicing dentists, using interviews, to explore their understanding of NCCL aetiology, the decision-making criteria of when to restore, and the restorative techniques used to restore NCCLs. This may help identify gaps or anomalies in our understanding to inform future research and clinical practice for the management of NCCLs.

METHODS

An interview guide was developed from a literature search which formed 2 domains framed around understanding and management of NCCLs based on: understanding of diagnosis and aetiology, and factors affecting decision making for management. Practicing dentists with more than 10 years of experience were purposively recruited to conduct in-depth, semi-structured interviews. Fifteen interviews were audio recorded and transcribed verbatim. A thematic content analysis was conducted and the results analysed.

RESULTS

From the thematic analysis, 2 domains were identified. In the domain of "diagnosis and aetiology", while participants have similar understanding and methods of diagnosing NCCL, most stated NCCLs in a patient were caused by a "main aetiology" such as "abrasion", "abfraction" while few described the inter-relationship of these aetiological factors. In the domain of "factors affecting decision making". "Patient reported symptoms" and "lesion dimension" were the main factors that affected participants' decision to provide restorative or non-restorative management. However, a "restorative threshold" was not able to be identified.

CONCLUSION

There was notable variety in participants' understanding of the aetiology, management, and treatment of NCCLs, particularly the restorative threshold of when to treat.

CLINICAL SIGNIFICANCE

The variability demonstrates the need to have a clearer understanding of the key elements that affect the management of NCCLs and better information to support the decision of when to treat.

Comparison of the shear bond strength in Giomer and resin-modified glass ionomer in class V lesions

Introduction

There are several cosmetic, restorative materials to restore non-carious Cervical Lesions (NCCLs). The aim of this study was to specify and compare the shear bond strength of Giomer and resin-modified glass ionomer in Class V lesions so that whether Giomer showed a better shear bond strength, it could be used instead of RMGI to restore NCCLs because of its better esthetic.

Method

ology: 20 maxillary and 20 mandibular intact premolars were collected. Each group of 20 samples was divided into two 10-tooth subgroups of A and B. A class V preparation was made on the buccal surface of the samples with 2*2*3 mm dimensions using a diamond bur. Also, the crossing path of the universal machine chisel was prepped with 2 mm depth up to incisal edge. For group A, after applying BeautiBond and curing it, Beautifil II Giomer was placed in nylon cylinders and the cylinders were placed in the middle cervical region and cured for 20 s. For group B, 1 spoon powder of Fuji II RMGI was mixed with two drops of its liquid and transported to nylon cylinders and placed in the middle cervical region, then cured for 20 s. The nylon cylinders were removed from all 40 samples. Then, all teeth were thermocycled and then tested using a universal machine with the force of 20 MPa and the speed of 1 mm/min until they fractured to assess their shear bond strength. The obtained data was analyzed using SPSS v.26. The significance level was considered 0.05.

Results

There was no significant difference between Giomer (4.97 ± 2.36) and the resin-modified glass ionomer (3.41 ± 2.71) groups as regards their shear strength (p = 0.059). Likewise, there was no significant difference in shear bond strength between Giomer and RMGI groups as regards jaw type (P = 0.326).

Conclusion

The paper suggests that Giomer and resin-modified glass ionomer groups did not differ significantly in terms of their shear bond strength and that both can be utilized to treat Class V lesions. Furthermore, there was no significant difference between the shear bond strength in terms of jaw type.

Comparative Evaluation of Microleakage of Flowable Composite Resin Using Etch and Rinse, Self-Etch Adhesive Systems, and Self-Adhesive Flowable Composite Resin in Class V Cavities: Confocal Laser Microscopic Study

The essential factor in determining the preservation of restoration is the marginal seal. Restoring cervical lesions with a resin composite has always been a challenge. Composite resins with various viscosities and different bonding systems are being researched to reduce the microleakage. Confocal laser scanning microscopy (CLSM) is the latest non-destructive technique for visualizing the microleakage. Objectives: To evaluate and compare the microleakage of Universal Flo composite resin (G-aenial) using etch and rinse adhesive system ER-2 steps (Adper Single Bond 2), self-etch adhesive system SE-1 step (G-Bond), and self-adhesive flowable composite resin (Constic) in Class V cavities using a confocal laser scanning microscope. Materials and Method: Class V cavities were prepared on 27 caries-free human extracted premolar teeth on the buccal and lingual surfaces with standardized dimensions of 2 mm height, width 4 mm, and a depth of 2 mm. After the cavity preparation, all teeth were randomly divided into three groups, namely Group-I: G-aenial Universal Flo with Single Bond 2 (n = 9 teeth); Group-II: G- aenial Universal Flo with G-Bond (n = 9 teeth), and Group-III: Constic (n = 9 teeth). The prepared and restored specimens were then subjected to thermocycling for 500 cycles in a water bath at 5 °C and 55 °C with a dwelling time of 30 s. The specimens were placed in 0.6% aqueous rhodamine dye for 48 h. Sectioning was carried out bucco-lingually and specimens were evaluated for microleakage under a confocal laser scanning microscope. Results: There was a significant difference (p = 0.009) in microleakage when comparing total etch and rinse, specifically between Adper Single Bond 2 ER-2 steps (fifth generation) and self-adhesive flowable composite resin, which is Constic. There was more microleakage in the self-etch bonding agent, particularly G-Bond, SE-1 step (seventh generation), when compared to ER-2 steps (fifth generation bonding agent); however, the results were not statistically significant (p = 0.468). The self-adhesive flowable composite resin showed more microleakage than SE-1 step and ER-2 steps. Conclusions: None of the adhesive systems tested were free from microleakage. However, less microleakage was observed in the total etch and rinse, especially Adper Single Bond 2 (ER-2 steps), than the self-etch adhesive system SE-1 step and self-adhesive flowable composite resin. Clinical significance: Constant research and technological advancements are taking place in dentin adhesives to improve the marginal seal. This has led to the evolution of total acid-etching dentin bonding agents termed as etch and rinse (ER)-2 steps (fifth generation dentin bonding agents) and self-etching (SE) 2 steps, and SE-1 step dentin bonding agents termed as the sixth and seventh generation bonding agents, respectively.

Progression of non-carious cervical lesions: 3D morphological analysis

OBJECTIVES

This longitudinal study aimed to investigate morphologically and quantitatively the progression of non-carious cervical lesions (NCCLs) using a confocal laser scanning microscope (CLSM) and replica models.

MATERIALS AND METHODS

The samples examined comprised sets of replicas annually obtained from 83 lesions in 16 participants over 3 to 5 years. All lesions were visually categorized as wedge-shaped, saucer-shaped, or mixed-shaped lesions. CLSM images of the replicas were analyzed in terms of axial depth, occlusogingival width (height) in the buccolingual cross-section, and estimated volume using a custom code of the image analysis software to estimate the progression of the NCCLs over time. The morphological characteristics of the NCCLs were also objectively divided into three groups according to the depth to height ratio (D/H ratio). Fisher's exact test and the Cochran-Armitage trend test were used for statistical analysis.

RESULTS

Saucer-shaped lesions progressed mainly in height, whereas wedge-shaped lesions increased both in height and depth. Annual progression in depth and volume significantly increased as the D/H ratio increased. More than half of the NCCLs with a small D/H ratio progressed 50 μm or more in height, whereas none of them progressed more than 50 μm in depth. Annual progression in depth significantly increased as the lesion depth at baseline increased.

CONCLUSIONS

Progression patterns significantly differed between NCCLs of different shapes. Most NCCLs progressed slowly in depth regardless of their shape. Moreover, NCCLs may progress through active and inactive stages.

Effect of fluoride mouthrinse and fluoride concentration on bonding of a one-step self-etch adhesive to bovine root dentin

This study investigated the effect of fluoride mouthrinses on bonding of a one-step self-etch adhesive to bovine root dentin. Application of a NaF solution (0, 450, 900, or 9,000 ppm) to bovine root dentin surfaces was performed for 30 s (immediate) or before bonding of an all-in-one adhesive. Microtensile bond strength (µTBS) testing and scanning electron microscopic (SEM) observation of the acid-base resistance zone (ABRZ) were performed. µTBS values and calculated ABRZ areas were analyzed by using two-way ANOVA and the t-test with Bonferroni correction. The significance level was set at P = 0.05 (n = 30). Fracture mode was analyzed with the Mann-Whitney U test with Bonferroni correction. The significance level set at P = 0.00178 (n = 30). µTBS did not significantly differ between the control, 450 ppm F, and 900 ppm F specimens (P > 0.05) but was significantly lower in 9,000 ppm F specimens (P < 0.05). SEM showed a significant increase in acid resistance at the adhesive-dentin interface, including the ABRZ, after fluoride application.

A Simple Method for Treating Subgingival Class V Lesions

Noncarious cervical lesions (NCCLs) are steadily increasing. Unfortunately, NCCL restorations represent one of the less durable types of restorations due to problems, including isolation and crevicular moisture control, especially in cases where the cervical margin is covered by soft tissue. This article presents a technique that allows us, through the use of a common metallic matrix, to isolate and make accessible class V cavities with intrasulcular cervical margins. The advantages and disadvantages of the technique are presented.

Three-year clinical evaluation of high-viscosity glass ionomer restorations in non-carious cervical lesions: a randomised controlled split-mouth clinical trial

OBJECTIVE

To compare the 3-year clinical performance of high-viscosity glass ionomer restorations with that of composite restorations in non-carious cervical lesions (NCCLs).

MATERIALS AND METHODS

One hundred thirty-four NCCLs were randomised into two groups according to a split-mouth design. In the experimental group (Hv-GIC), lesions were restored with a high-viscosity glass ionomer (EQUIA Fil, GC), whereas a composite resin (G-aenial, GC) was applied in the control group (E&Ra/comp). All restorative materials were used according to the manufacturers' instructions. Clinical evaluations were performed after 1 week, 6 months, 1 year, 2 years, and 3 years using FDI (World Dental Federation) criteria. Data were analysed using Friedman's ANOVA and Mann-Whitney U tests (α = 0.05).

RESULTS

While retention rates of the Hv-GIC group were 98.5%, 96%, 91%, and 87% in respective evaluation periods, no retention loss was observed in the E&Ra/comp group at any time. There was a statistically significant difference between study groups regarding the retention criterion in both the second and third years (p = 0.008 and p = 0.003, respectively). Furthermore, there was a statistically significant difference between the groups in terms of surface lustre at the third-year recall, in favour of the E&Ra/comp group (p = 0.022).

CONCLUSIONS

The 3-year clinical performance of E&Ra/comp restorations in NCCLs was better than that of Hv-GIC restorations. The most common problems in Hv-GIC restorations were a loss of retention and reduction in surface lustre.

CLINICAL RELEVANCE

Although the 3-year clinical performance of Hv-GIC restorations in non-retentive lesions was acceptable, it was worse than in composites. The operator should consider the benefit/loss ratio of Hv-GIC when he/she decides to use this material in non-retentive cavities, especially those that are shallow.

Effect of fluoride mouthrinse on adhesion to bovine root dentin

The purpose of this study was to evaluate the effect of fluoride mouthrinses on dentin bonding performance of a two-step selfetch adhesive; Clearfil SE Bond. Bovine root dentin surface was treated with either 450, 900, or 9,000 ppm F solutions for 30 s (immediate), and continually treated for one month (one month) before the bonding procedures. Microtensile bond strength (µTBS) test and scanning electron microscopic (SEM) observation of the acid-base resistance zone (ABRZ) were performed. Chemical state of fluorine on dentin surface was analyzed by X-ray absorption fine structure (XAFS). The 450 and 900 ppm F fluoride mouthrinses did not influence the µTBS to dentin, while the 9,000 ppm F fluoride solution adversely affected the µTBSs. The fluoride application to dentin significantly enhanced acid resistance at the adhesive/dentin interface including the ABRZ. The XAFS analysis indicated different concentrations of fluoride might create different chemical compounds on the dentin surface, influencing the µTBS results.

A pilot study to assess the morphology and progression of non-carious cervical lesions

OBJECTIVE

This longitudinal pilot study aimed to morphologically and quantitatively investigate the progress of non-carious cervical lesions (NCCLs) by using swept-source optical coherence tomography (SS-OCT).

METHODS

The samples examined comprised sets of NCCL epoxy resin replicas obtained from 10 lesions in 6 patients who attended annual dental visits over 4 or 5 years. SS-OCT images of the replicas were analyzed in terms of the maximum depth (D_max) and corresponding vertical width (VW) - using an image analyzer to estimate progression of the NCCLs over time.

RESULTS

It was found that differences between wedge- and saucer-shaped lesions were morphologically distinguished well by the OCT images. There were significant differences in dimensions among D_max, VW and horizontal width (HW). HW was the largest and D_max was the smallest. Although no significant differences in absolute values of annual progression rates were found among D_max, VW and HW, the percentage increase in D_max was significantly greater compared to VW and HW. The ratios of D_max to corresponding VW ranged from 0.49 to 1.01 for the wedge-shaped lesions and from 0.13 to 0.44 for saucer-shaped lesions, respectively.

CONCLUSIONS

The dimensional analysis demonstrated notable progression with large variations. The wedge-shaped lesions appeared to show greater D_max values compared to the saucer-shaped lesions.

CLINICAL SIGNIFICANCE

With respect to the depth, the wedge-shaped lesions may progress at a greater rate compared to the saucer-shaped lesions.

Abfraction: A review

Abfraction (AF) is the pathological loss of tooth substance caused by biomechanical loading forces that result in flexure and failure of enamel and dentin at a location away from the loading. The theory of AF is based primarily on engineering analyses that demonstrate theoretical stress concentration at the cervical areas of the teeth. However, the theory is not yet proven and there are explanations against it. AF lesions present primarily at the cervical region of the dentition and are typically wedge-shaped, with sharp internal and external line angles. Diagnosis of AF plays a very important role in the management of patients. The aim of the present narrative review is to comprehensively discuss the historical, etiopathogenetic, clinical, and diagnostic and treatment aspects of AF.

Restoration of noncarious cervical lesions: when, why, and how

At this time, restoration of noncarious cervical lesions (NCCLs) is a common occurrence in clinics nowadays. Some reasons for this are the growth of the elderly population, a smaller rate of tooth loss, and possibly the increase of some etiologic factors. These factors include inadequate brushing techniques in gingival recession cases, corrosive food and drink consumption, and occlusal stress concentrating factors (occlusal interferences, premature contacts, habits of bruxism, and clenching). Unfortunately, Class V restorations also represent one of the less durable types of restorations and have a high index of loss of retention, marginal excess, and secondary caries. Some causes for these problems include difficulties in isolation, insertion, contouring, and finishing and polishing procedures. This work aims to help dentists in choosing the best treatment strategy, which necessarily involves steps of problem identification, diagnosis, etiological factor removal or treatment, and, if necessary, restoration. Finally, appropriate restorative techniques are suggested for each situation.

Characteristics of non-carious cervical lesions--an ex vivo study using micro computed tomography

The aetiology of non-carious cervical lesions (NCCLs) is not well understood and still controversial. The aim of this ex-vivo study was to examine the morphological characteristics of NCCLs for clinical evidence of enamel loss above the cemento-enamel junction (CEJ) as suggested by the abfraction theory. Fifty extracted human teeth with various types of NCCLs were collected and scanned by micro computed tomography. The reconstructed three-dimensional models were evaluated from multiple aspects, including longitudinal cross-section series. The location of internal line angle and proximal exits of the lesions were evaluated in relation to the level of CEJ. The coronal margins of the lesions were inspected for evidence of enamel loss above the CEJ using the bucco-lingual longitudinal sectional images. Coronal margins of the lesions were located along and/or under the CEJ for all of the 50 samples. In most of the lesions, regardless of lesion type, the proximal exits and internal line angles were located below the CEJ. This study did not detect clinical evidence of enamel loss above the occlusal margin of NCCLs as would have been expected according to the general abfraction mechanism.

Predictors of Non-carious Loss of Cervical Tooth Tissues

In this sample of subjects, age, premolars and the presence of corrosive factors were found to be significantly associated with NLCTT. The long-term success of treating such a lesion is dependent on properly identifying and eliminating the etiologic factors.

Noncarious cervical lesions and abfractions: a re-evaluation

BACKGROUND

The concept of abfraction is controversial. The authors present the fundamental basis of abfraction and review studies that describe the condition.

TYPES OF STUDIES REVIEWED

The authors used data on masticatory forces, enamel and dentin properties, as well as stress studies related to abfraction, for background information. They also analyzed the genesis of the abfraction theory, experimental evidence, case presentations, clinical investigations and restorative studies.

RESULTS

The theory of abfraction is based primarily on engineering analyses that demonstrate theoretical stress concentration at the cervical areas of teeth. While some recent stress studies support earlier findings, others have provided significant deviating information. Few controlled studies exist that demonstrate the relationship between occlusal loading and abfraction lesions. The role of occlusal loading in noncarious cervical lesions (as shown by clinical data) appears to be part of a multifactorial event that may not necessarily follow the proposed classic abfraction mechanism, and other mechanisms or factors may explain cervical restoration failure just as well.

CLINICAL IMPLICATIONS

There is little direct evidence supporting the theory of abfraction as the primary factor in the formation of noncarious cervical lesions. Controlled clinical trials are necessary to elucidate more fully the etiology of those lesions.