Comparative Evaluation of Chemo-mechanical and Rotary-mechanical Methods in Removal of Caries with Respect to Time Consumption and Pain Perception in Pediatrc Dental Patients

INTRODUCTION

The chemomechanical caries removal (CMCR) has been introduced as an alternative to the invasive method of caries removal which aims at the elimination of carious dentin with help of chemical agents. By this method only infected tissues are being removed, it helps in preserving healthy dental structures, avoiding pulp irritation and the patient does not have to go under any discomfort. Instead of using the conventional drilling method, using a chemical agent assisted by an atraumatic mechanical force to remove soft carious tooth structure has been an affable option. This work intends to perform a comprehensive study of old and most recently available methods for CMCR.

According to WHO, caries is defined as a “localized post eruptive, pathological process of external origin involving softening of hard tissue and proceed to the formation of a cavity”.¹

During the invasive treatment of caries using high-speed instrument, the operator is forced to destroy the sound tooth structure. Heat, vibration, and bone-conducted noise; all contribute to patient discomfort and it has an adverse effect on pulp (thermal and pressure).² So, even though it can quickly and efficiently remove caries, it can result in pain or discomfort which is a common phenomenon often inducing fear and anxiety in pediatric patients.

Caries excavation has conventionally been performed according to the mechanical principles using drills and sharp-edged hand instruments. These methods, although often effective, have some major disadvantages that can result in heat, pressure, dentin desiccation, vibration, and pain.³ First, due to the apparent lack of objective clinical markers, the amount of dentin to be removed is often difficult to establish. Second, it often induces pain and discomfort; therefore, local anesthesia is needed.⁴ To prevent these drawbacks, alternative dentin caries-removal methods have been proposed, including chemomechanical techniques,^5,6 air abrasion with aluminum oxide or glass particles,⁷ sono-abrasion,⁸ ultrasonic instrumentation,⁹ and lasers.¹⁰ The advantages of CMCR agents increased patient’s compliance, avoided usage of local anesthesia,¹¹ left the healthy dentin intact,¹² and facilitated ultimate tissue preservation.

PROCEDURE FOR APPLICATION

RESULTS

The patients were randomly assigned to two different groups using the conventional rotary method and Carisolv. The distribution of patients in two groups is shown in Table 1 and the result is based on the following categories:

DISCUSSION

Carisolv gel (MediTeam, Sweden) was launched in 1998. Its effectiveness is based on the proteolytic action of sodium hypochlorite, which dissolves the infected dentin, and on the action of amino acids, which enhance the effect of sodium hypochlorite on denatured collagen and minimize damage to healthy tissue.¹³

So far the most promising method gaining a position as an alternative to the conventional method is chemomechanical elimination of the carious dentin, well suited in primary teeth in pediatric patients, especially those who are dental phobic and are mentally compromised. In the present study, the purpose of the chemomechanical caries excavation is to provide less invasive caries treatment by applying a solution to the outer infected, destroyed and, non-remineralizable carious dentin to soften this layer, thereby making it easier to remove using hand instruments.¹⁴

The gel comprises a clear fluid of high viscosity which contains three different amino acids (glutamic acid, leucine, and lysine), sodium chloride, water, and sodium hydroxide, and a transparent fluid consisting of 0.95 of sodium hypochlorite. When the gel and fluid are mixed, amino acids bind chlorine and form chloramines at a pH of 11.52. The formation of chloramines reduces the reactivity of chlorine without altering its chemical function. The result of this process is a breakdown of degraded collagen found in a demineralized portion of a caries lesion. The degraded collagen has an open structure and is, therefore, more susceptible to further breakdown by chloramines. The porous nature of demineralized dentin allows penetration of Carisolv. The unaffected collagen is more resistant to degradation but the framework of degraded collagen is broken down and can be easily scraped away.

The Carisolv is a gel-based system and in this study, it was used with specially designed hand instruments to abrade the carious dentin surface. At room temperature, the gel supplied in a twin syringe was mixed before use and then applied onto the exposed carious dentine using hand instruments and left for 60 seconds before excavation. While using Carisolv, the clouding of the applied gel is given as the caries indicator by the manufacturer. When the gel no longer turns cloudy, the cavity is indicated to be caries free.¹⁵ The purpose of the excavation with Carisolv is to remove the soft irreversibly damaged, highly infected dentinal tissue, while conserving the reversely affected dentin. Caries-affected dentin is useful because of its low permeability compared to healthy dentin, which protects the pulp from any remaining bacteria. According to Pashley, in response to the carious process, the odontoblast precipitates calcium phosphate to form plugs in the dentinal tubules, creating the odontoblastic reaction zone. When this effect is combined with isolation of bacteria from the external sources of nutrients, caries progress has been shown to be arrested over periods up to 10 years.¹⁶

In the present study, it was noticed that the actual dimensions of the cavity were larger than was apparent clinically on the occlusal surface. Hence, to record all the details of the cavity, including undercuts, an addition of silicone impression material was used. Johnson and Craig showed addition silicone to demonstrate the best recovery from undercuts and extremely high accuracy with superior tear resistance plus less polymerization shrinkage, increased dimensional stability, and neutral odor and taste; besides, it permits multiple accurate casts. Polyvinyl siloxane material shows 96.86% overall accuracy.¹⁷

With the help of CMCR selectively carious dentine is removed but avoids the painful and unnecessary removal of sound dentine. It facilitates delivery of atraumatic, bactericidal, and bacteriostatic activity and helps to remove the least amount of tooth structure, not leaving behind any infected and untreatable dentin.¹⁸

CONCLUSION

Within the limitations of this study comparing the clinical efficiency of CMCR using Carisolv and conventional airotor, the following conclusions could be drawn:

• Minimally-invasive, selective, and precise.
• Minimizes the need for anesthesia and enhances patient comfort.
• Makes it possible to avoid drilling close to the pulp and making treatment painless.

During the last 15 years, it has been used almost exclusively in pediatric dentistry; as the use of Carisolv in clinical practice might be limited because of the material cost.

CLINICAL SIGNIFICANCE

Due to the shortcomings of the conventional drill method (noise and pressure) which leads to fear and anxiety among patients, alternative techniques like air abrasion, ultrasonic instrumentation, lasers, and chemomechanical approach to caries removal were developed. Reason being costly, air abrasion, sono-abrasion, ultrasonic instrumentation, and lasers are therefore less frequently used.

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