Scanning electron microscopy study to analyze the morphological characteristics of root surfaces after application of Carisolv gel in association with scaling and root planing: In vitro study

Abstract

Context:

There has been considerable interest in the use of chemical-assisted root detoxification. Chemical agents have been proposed to facilitate calculus removal.

Aims:

A study was carried out to analyze the morphological characteristics of the root surfaces after application of Carisolv gel in association with scaling and root planing under scanning electron microscopy (SEM).

Settings and Design:

The Department of Periodontics of the K. M. Shah Dental College and Hospital, Vadodara, (Gujarat, India).

Materials and Methods:

Sixty periodontally compromised extracted human teeth were randomly assigned to four groups: (1) scaling and root planning (SRP) alone; (2) passive topical application of Carisolv + SRP; (3) active topical application of Carisolv + SRP; (4) multiple applications of Carisolv + SRP. Carisolv gel was applied to the root surfaces for 30 seconds, followed by scaling and root planing, consisting of 30 strokes, with Gracey curettes in an apical-coronal direction, parallel to the long axis of the tooth. The only exception was group 4, where the roots were instrumented until a smooth, hard, and glass-like surface was achieved. All specimens were further analyzed by SEM.

Statistical Analysis:

The Analysis of Variance (ANOVA) method was used.

Results:

Active application of Carisolv gel produced more extensive morphological changes than passive application and SRP alone. When multiple applications of Carisolv with SRP were performed, there was a significant decrease in the smear layer compared to a single application of the gel, either passively or actively.

Conclusions:

The Carisolv gel failed to remove the smear layer completely, especially with a single application, independently of the method of application. This study documented that the Carisolv gel produced changes in the root morphology of periodontally compromised teeth, only when it was applied actively and multiple times.

INTRODUCTION

In periodontal disease, the root surface is exposed to the oral environment and bacterial plaque. Exposure to crevicular fluid, as well as to enzymes and metabolites produced by subgingival plaque bacteria, induces physical and chemical alterations in the root cementum. Periodontitis-affected root surfaces are hypermineralized[1,2] and contaminated with bacterial plaque[3] and other cytotoxic substances.[4]

Scaling and root planing procedures have relied on the mechanical removal of plaque, calculus, root-bound toxins, and contaminated cementum. Although the effectiveness of scaling and root planing has been well-documented, the efficacy of this treatment has been questioned. Additionally, the smear layer that remains after instrumentation can impair periodontal healing.[5,6]

There has been considerable interest in the use of chemical-assisted root detoxification. Chemical agents have been proposed to facilitate calculus removal,[7,8] removal of the smear layer and root-associated endotoxins,[5,9,10] and decalcifying of planed root surfaces, exposure of the dentin or cementum collagen matrix, thus providing a biologically acceptable surface for the regeneration of a new connective tissue attachment.[11,12]

Different etching solutions, such as, citric acid, tetracycline, and Ethylenediaminetetraacetic acid (EDTA), were used as adjunctive therapies for scaling and root planing in order to overcome the limitations of these procedures. Carisolv gel (Mediteam, Savadelen, Sweden), a chemomechanical caries removal system, was developed to aid carious dentin excavation. This system consisted of sodium hypochlorite and three amino acids (lysine, leucine, and glutamic acid), which were able to remove carious tissue, without affecting the healthy dentin structure.[12–14]

The use of chemical agents in association with mechanical treatment represents the possibility of a less traumatic procedure, preventing the excessive loss of root substance. In the field of periodontics, the possibility of chemically dissolving calculus and contaminated root cementum in order to facilitate their mechanical removal is one of the most promising applications of Carisolv gel.

Previous studies on periodontally compromised human root surfaces using carisolv have found that chemomechanical therapy caused significant changes in the root surface morphology of periodontally involved teeth compared to SRP alone, but only when Carisolv was applied using the burnishing technique.

Therefore, the purpose of this study was to investigate the morphological characteristics of periodontally compromised human root surfaces, after application of Carisolv gel, in association with scaling and root planing under scanning electron microscopy (SEM).

MATERIALS AND METHODS

Sixty periodontally compromised extracted human teeth with subgingival calculus were used from the Department of Periodontics of the K. M. Shah Dental College and Hospital, Vadodara (Gujarat, India), and were stored in saline until use. The research protocol was approved by the local Ethics Research Committee. Diseased tooth surfaces with adhered calculus were chosen as the treatment areas and delineated with a round bur, and the teeth were randomly assigned to four groups (n=15), as follows, Group 1: Scaling and root planing (SRP) alone. The root surfaces were instrumented with Gracey curettes (Hu-Friedy, Chicago, IL, USA), using 30 strokes in an apical-coronal direction, parallel to the axis of the tooth; Group 2: Passive topical application of Carisolv gel + SRP; Carisolv gel was applied to the delineated area in each root for 30 seconds. The root surfaces were instrumented with Gracey curettes in the same way as described as in group 1; Group 3: Active topical application of Carisolv gel + SRP; Carisolv gel was burnished onto the delineated areas for 30 seconds, using a disposable microbrush tip. Root surfaces were instrumented with Gracey curettes, in the same manner as described in groups 1 and 2; Group 4: Multiple applications of Carisolv gel + SRP. Carisolv gel was applied several times interposing with the SRP procedures, which were performed with Gracey curettes in order to provide a smooth, hard, glass-like surface. The teeth were instrumented with hand instruments simulating a clinical situation. The treated surfaces were rinsed in 20 ml saline and the crowns were removed at the cementoenamel junction. The teeth were then horizontally and vertically sectioned with a diamond circular saw, using the treated area as a reference. Each tooth section was rinsed in saline and placed in 2.5% glutaraldehyde, in 0.1 M phosphate buffer (pH 7.4), for a minimum of 24 hours. The specimens were washed and dehydrated in a series of graded alcohol solutions (50, 70, 80, 95, and 100%) for 10 minutes each. After two additional 10-minute washes in absolute alcohol, the specimens were dried overnight in a desiccators jar, mounted on SEM stubs, and sputter-coated with gold. The specimens were examined using a scanning electron microscope (JSM-5610LV; JEOL, Gujarat, India). Photographs of the central portion of each specimen were taken at X1000 magnification. The SEM examination was performed by a single blinded examiner. The following parameters were evaluated: surface morphology (regular, irregular or flaky surface), presence or absence of smear layer, and presence or absence of dentinal tubules. The data were analyzed by multivariate analysis of variance (MANOVA), to determine the statistically significant differences among the four treatment groups. The Newman-Keuls test was used to determine the differences between the individual groups at a 5% significance level.

RESULTS

The results of SEM analysis are presented in Table 1.

Table 1.

Frequency of root surface characteristics, smear layer, and dentinal tubules in each group

Group 1: There were no statistically significant differences in the regular surfaces (P>0.05) between group 1 and the other groups. All specimens were covered with a smear layer.

Group 2: Topical application of Carisolv plus SRP had more irregular surfaces compared to group 4 (P<0.05). In comparison to the other groups, there were no statistically significant differences in the regular (P>0.05) or flaky surfaces (P>0.05). All specimens were covered with a smear layer.

Group 3: Active application of Carisolv plus SRP had a regular surface, with no statistically significant differences compared to the other groups (P>0.05). In comparison to the SRP specimens, the active application of Carisolv gel resulted in fewer irregular surfaces (P<0.05).

Group 4: Multiple applications of Carisolv interposed with SRP procedures had more regular surfaces, with no significant difference compared to the other groups (P>0.05). No differences were observed between the treatments with respect to flaky surfaces (P>0.05). There was a statistically significant reduction in the amount of smear layer when this group was compared to groups 2 and 3 (P<0.05).

DISCUSSION

The root surface exposed to the oral environment undergoes numerous changes, which make root planing a pre-requisite for new-attachment in periodontal therapy. Root planing is a definitive treatment procedure designed to remove cementum or dentine that is rough, impregnated with calculus or contaminated with toxins or microorganisms, and to create clinically smooth and biologically clean root surfaces.

This study compared the morphological changes of periodontally compromised root surfaces submitted to either treatment with Carisolv gel combined with mechanical instrumentation or scaling and root planing alone.

When Carisolv gel was passively applied to root surfaces before scaling or root planing, there were no significant changes in the root surface morphology compared to mechanical treatment alone. Both treatments resulted in a higher frequency of rough surfaces. The irregular appearance of root surfaces treated with SRP or SRP + Carisolv was partially due to the presence of a smear layer [Figures 1 and 2]. In Group 2, the flaky surfaces were more frequently observed in chemomechanically treated specimens. These morphological characteristics were similar to those observed by Bannerjee et al.[15] This could be due to the chemical effect of Carisolv gel on the root surface of periodontally compromised teeth. The main constituent of Carisolv was sodium hypochlorite, which was mixed with three amino acids. The resulting gel would be able to remove the organic components of root cementum or calculus, in the same manner as it did in those of carious lesions. Additionally, this gel would be able to reduce the smear layer formation, because it was usually used simultaneously with mechanical instruments, thus acting as a lubricating gel.

Figure 1.

Group 1 – SEM micrograph of diseased root surface after scaling and root planing. The surface is irregular and covered by smear layer remnants

Figure 2.

Group 2 – SEM micrograph of diseased root surface after passive application of Carisolv gel plus scaling and root planing. The surface is regular and covered by smear layer remnants

Active application of Carisolv gel produced more extensive morphological changes than passive application and SRP alone This mode of application resulted in fewer irregular surfaces, probably due to the mechanical abrading action of the microbrush soaked in Carisolv gel, which also allowed this agent to be in closer contact with the root surface [Figure 3]. These results are in agreement with those of the previous studies,[16,17] which observed lack of smear layer after multiple applications of Carisolv gel, for removal of the carious dentine. When multiple applications of Carisolv with SRP were performed, there was a significant decrease in the smear layer compared to the passive and active applications [Figure 4]. Some specimens of Group 4 showed the appearance of having a healthy cementum. Carisolv gel was also able to remove the contaminated cementum layer and expose the healthy structure. These results are in agreement with those of previous studies[15] , which observed a lack of smear layer after multiple applications of Carisolv gel for removal of the carious dentine.

Figure 3.

Group 3 –; SEM micrograph of diseased root surface after active application of Carisolv gel plus scaling and root planing. The surface is irregular and covered with smear layer remnants

Figure 4.

Group 4 –; SEM micrograph of diseased root surface after multiple applications of Carisolv gel interposed with scaling and root planing. The surface is irregular and free of smear layer

CONCLUSION

SRP alone and passive application of Carisolv gel failed to remove the smear layer completely. Active application and multiple applications of Carisolv gel were able to achieve significant changes in the root surface morphology and a reduction in the smear layer of periodontally compromised teeth. In the field of Periodontics, the possibility of chemically dissolving calculus and contaminated cementum, to improve their removal by mechanical removal, is one of the most promising applications of Carisolv gel.