Australian Dental Journal

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1 Australian Dental Journal The official journal of the Australian Dental Association Australian Dental Journal 2014; 59: doi: /adj Current update of chemomechanical caries removal methods H Hamama,* C Yiu,* M Burrow* *Faculty of Dentistry, Prince Philip Dental Hospital, University of Hong Kong, Hong Kong SAR, China. Department of Conservative Dentistry, Faculty of Dentistry, Mansoura University, Egypt. Melbourne Dental School, The University of Melbourne, Victoria, Australia. ABSTRACT Chemomechanical caries removal is an excellent method for minimally invasive caries excavation, and the removal agents are either sodium hypochlorite (NaOCl)- or enzyme-based. The NaOCl-based agents include GK-101, GK-101E (Caridex) and Carisolv, and the enzyme-based agents include Papacarie and the experimental material, Biosolv. This review outlines the changes in chemomechanical caries removal methods and focuses on recently published laboratory and clinical studies. The historical development, mechanism of action, excavation time and biological effects on pulp and dental hard tissues are described. Based on existing evidence, the currently available chemomechanical caries removal methods are viable alternatives to conventional rotary instrument methods. Chemomechanical methods could be extremely useful in very anxious, disabled and paediatric patients. It does seem some of these agents would still benefit from quicker excavation times in order to achieve more universal acceptance. However, as a means of conserving the caries-affected dentine, chemomechanical caries removal is possibly much more successful than conventional rotary instrumentation. Keywords: Biosolv, Caridex, Carisolv, chemomechanical caries removal, minimal intervention dentistry, Papacarie. Abbreviations and acronyms: EDTA = ethylene diamine tetra-acetic acid; FDA = US Food and Drug Administration; NaOC1 = sodium hypochlorite; VAV = Visual Analogue and Verbal scale; WBFP = Wong Baker Faces Pain scale. (Accepted for publication 7 January 2014.) INTRODUCTION The philosophy of minimally invasive caries removal is one of the most important applications of the minimal intervention dentistry concept established during the last decade. 1 The use of laser ablation, 2 air abrasion, 3 sono-abrasion 4 or chemomechanical agents 5 for the removal of infected dental tissue has greatly aided minimal invasive caries removal techniques. The common feature of these techniques is the selective removal of caries-infected tissue, whilst leaving intact the caries-affected tissue. The caries-affected dentine is characterized by demineralization of the intertubular dentine, deposition of crystals in tubules, minimal destruction of the collagen matrix and no bacterial penetration. 6 Conversely, the caries-infected dentine shows distortion of the dentinal tubules microstructure, irreversible denaturing of the collagen fibres and marked bacterial invasion. 6 It is the latter damaged tissue that should be removed during caries excavation. The principle of chemomechanical caries removal is the use of a solution to chemically alter carious tooth tissue to further soften it, thus facilitating its easier removal. The softened dentine is then mechanically removed using a hand instrument. Early attempts were introduced in the 1970s using various agents such as ethylene diamine tetra-acetic acid (EDTA), 7 collagenase 8,9 and sodium dodecyl sulfate. 8 Most of these systems proved too time consuming to be of any use clinically. More recently, other agents have become available; the best known is Carisolv (Mediteam, G oteborg, Sweden). In the last decade, several chemomechanical caries removal agents have been removed from the market or been improved. One new agent has also been introduced and a further one is currently under development. It has been more than 10 years since the chemomechanical caries removal method 5,10,11 was reported and several changes have occurred to improve its usefulness. Thus, it is timely to review current knowledge and outline where research gaps still remain. Due to the introduction of new agents, chemomechanical caries removal agents can now be classified into either sodium hypochlorite (NaOCl)- or enzyme-based agents (Table 1) Australian Dental Association

2 Chemomechanical caries removal methods Sodium hypochlorite (NaOCl)-based chemomechanical caries removal agents NaOCl-based chemomechanical caries removal agents depend on NaOCl derivatives, which chlorinate and disrupt hydrogen bonds of partially degraded collagen in carious dentine, thus facilitating its removal. 5 From 1972, a 5% NaOCl solution was used as a chemomechanical caries removal agent; however, it was unstable 10 and lacked selectivity and removed both cariesinfected and caries-affected, as well as sound dentine. 12 To overcome this problem, amino acids were added to the subsequent versions. GK-101 The next development was a chemomechanical caries removal solution introduced by Goldman and Kronman in 1976 and marketed as GK In the same year, GK-101 was approved by the United States Food and Drug Administration (FDA). 13 GK-101 consisted of 0.05% N-monochloroglycine (NMG) and NaOCl, and was prepared by mixing two solutions. Solution A consisted of 25 ml each of 2M NaCl, 2M NaOH and 2M glycine, and solution B consisted of 10 ml of 4 6% NaOCl. 13 GK-101 required a special delivery system consisting of a reservoir (for warming the freshly prepared solution to 41 C) and a pump (similar in shape to a straight handpiece) attached to a 20-gauge needle delivery tip. The delivery tip was applied to the carious lesion with minimal pressure via a paintbrush-like motion, 13 since it was reported that excessive pressure led to an increase in the patient s pain response and blocked solution flow through the needle tip. 13 GK-101 disrupted the organic structure of dentine by conversion of hydroxyproline (an essential factor for the stability of collagen) to pyrrole-2-carboxyglycine. 5 Few studies evaluated the GK-101 solution; however, Goldman and Kronman 13 reported that the mean caries excavation time for GK-101 was 8.5 minutes and using burs remained an essential subsequent step in order to achieve ideal finishing of the excavated sites. Laboratory findings showed GK-101 had no adverse effects on red or white blood cells or the platelet count. 13 Kurosaki et al. 14 reported that GK-101 had no adverse effect on the pulpal tissue of dogs; however, they concluded GK-101 was not efficient in removing the entire carious lesion. These findings led to improvements in the formula of GK-101 to GK-101E. GK-101E (Caridex) GK-101E is the ethyl derivative [N-monochloro-DL- 2 amino butyrate (NMAB)] of GK-101 (NMG). It was claimed this formula increased the specificity of the solution towards denatured protein of cariesinfected dentine. 15 The mechanism of action of NMAB on denatured collagen fibrils was similar to that of NMG, which involved the chlorination of the partially degraded collagen in the carious lesion and the conversion of hydroxylproline to pyrrole-2- carboxylic acid. 11 In addition to the chlorination reaction, cleavage of the denatured collagen fibrils might have occurred as a result of the oxidation of glycine residues. 11,16 Furthermore, Schutzbank et al. 15 reported that the improved formula seemed to be effective in shortening the caries excavation time. They attributed this time difference to the lag period (time between the application of the solution and true active caries removal). 15 The NMG solution exhibited a lag period of 30 to 90 seconds. Conversely, NMAB solution showed no lag period. 15 Most other studies were in disagreement with the claims of Schutzbank et al., 15 and it was reported that Caridex chemomechanical caries removal was time consuming in comparison with conventional caries removal methods GK-101E was marketed as Caridex TM (National Patent Dental Products, Inc., New Brunswick, NJ, USA) and received FDA approval in The Caridex system was critically evaluated, demonstrating its caries removal efficiency, 15 biocompatibility 13 and pulpal safety Many studies reported that using Caridex did not enhance the caries removal process compared to irrigation of the carious lesions with copious volumes of isotonic saline solution. 23,24 Furthermore, one of the most important drawbacks of the Caridex system was its complex delivery equipment (Fig. 1). 5,10 Yip et al. 24 reported that the addition of urea to Caridex enhanced the efficiency of caries excavation in deciduous teeth. The clinical usage and acceptance of both GK-101 and GK-101E solutions was very limited because neither showed a significant improvement in caries excavation compared with the conventional caries removal methods. Carisolv At the time of writing, Carisolv is the only commercially available NaOCl-based chemomechanical caries removal agent. In 1998, Carisolv (Medi Team Dentalutveckling AB, G oteborg, Sweden) was introduced as the latest variation of the NaOCl-based chemomechanical agents. 25 Although Carisolv has a similar chemical structure to Caridex, it has the advantage that it requires neither heating nor, because of its gel form, a special delivery system. 25 The original Carisolv was red in colour, consisted of two syringes; one containing carboxy-methylcellulose-based gels and amino acids (glutamic, leucine and lysine); the other containing 0.25% NaOCl (Fig. 2a) Australian Dental Association 447

3 H Hamama et al. Table 1. A summary of the chemical formula, mode of action and manufacturer recommendations of the different chemomechanical caries removal agents CMCR agent Chemical formula Mode of action Year of introduction Manufacturer Commercial availability Special instrumentation GK-101 Solution A: 0.05% N-monochloroglycine Solution B: 4-6% NaOCl. GK-101E (Caridex) Solution A: N-monochloro-DL-2 amino butyrate (NMAB) Solution B: 4-6% NaOCl. Carisolv Original gel (before 2004): (Fig. 2a) Syringe A: carboxymethylcellulose-based gels, colouring agent and amino acids (glutamic, leucine and lysine) in one Syringe B: 0.25% NaOCl in the other Modified gel (after 2004) Multimix syringe (Fig. 2b) the red colouring agent was removed, the amino acid concentration was reduced by half and the NaOCl concentration was increased to 0.475% New Carisolv System TM (2013) (Fig. 2c) Incorporation of minimally invasive burs and special Carisolv caries detector dye to the modified Carisolv gel to shorten the caries excavation time Chlorination of the denatured collagen by conversion of hydroxyproline (essential factor of the stability of collagen) to pyrrole-2- carboxyglycine Same as GK-101 (chlorination mechanism) + cleavage of the denatured collagen fibrils as a result of the oxidation of glycine residues Similar to Caridex, except, the replacement of monoaminobutyric acid by three different charged amino acids. These acids were shown to react with different moieties of carious lesion Need special delivery equipment 1984 National Patent Dental Products, Inc., New Brunswick, NJ, USA 1998, then modified at 2004 by Fure and Lingström, 24 and in 2013 the New Carisolv System was introduced Medi Team Dentalutveckling AB, now Rubicon Life Science AB, G oteborg, Sweden Commercialized under the name of Caridex, however, currently disappeared from market Need special delivery equipment (Fig.1) Available Non-cutting tip Carisolv hand instruments (Fig. 3) New Carisolv System TM : Ceraand Polymer Burs (Komet, UK) (Fig. 2c) NaOCl-based CMCR (continued) Australian Dental Association

4 Chemomechanical caries removal methods Table 1. continued CMCR agent Chemical formula Mode of action Year of introduction Papacarie Papain enzyme, chloramine, toluidine blue, salts, preservatives, a thickener, stabilizers and deionized water (Fig. 5) 2003 (Formula & Acao, Brazil). Manufacturer Commercial availability Special instrumentation Available Manufacturer recommends using back of blunt spoon excavator Enzyme-based CMCR Biosolv (SFC-V and SFC-VIII) Pepsin enzyme in a phosphoric acid/sodium biophosphate buffer The precise mechanism of action of the enzymebased chemomechanical caries removal agents remains unclear. Bussaduri et al. 53 reported that the enzymatic caries removal method was based on the fact that infected carious tissues lost the antiprotease a-1-antitrypsin. Recent study 56 reported no evidence a-1-antitrypsin could be identified in dentine. Reported the action of Papacarie was result of degradation of proteoglycans of dentinal matrix, suggesting that the action of papain might be non-specific. 56 Phosphoric acid dissolves the inorganic components of caries-infected dentine; while permitting the pepsin enzyme to selectively disrupt the denatured collagen fibres 2006, then developed in M-ESPE AG, Seefeld, Germany Not available (experimental gel) Initially manufacturer recommends using special plastic instruments (STAR V1.3). Recently, recommended to use in conjunction with metallic instruments 2014 Australian Dental Association 449

5 H Hamama et al. (a) (b) Fig. 1 (a) Caridex delivery equipment. (b) Caridex delivery tip (needle). (Published with permission by the Academy of General Dentistry. Copyright 1986 by the Academy of General Dentistry. All rights reserved.) (a) (b) (c) Fig. 2 Carisolv gel (Medi Team Dentalutveckling AB, Sweden). (a) Original Carisolv gel. (b) Modified gel (multimix syringe). (c) New Carisolv System TM. Finger pointer shows Cera-bur (Komet), the arrow head pointed to the polymer bur (Komet), and the hand pointer shows the Carisolv caries detector dye. Mechanism of action Ericson et al. 25 reported that the chemical structure and the mechanism of action of Carisolv was similar to Caridex, except that the monoaminobutyric acid was replaced by three different amino acids (listed above). The amino acids were shown to react with different moieties of carious lesions. 25 Furthermore, the addition of carboxy-methylcellulose created a higher viscosity of the Carisolv gel, which enhanced its handling properties compared to the Caridex solution. 26 In 2004, Carisolv was modified by removing the red colouring agent, decreasing the amino acid concentration by half and almost doubling the NaOCl concentration from 0.25% to 0.475% (Fig. 2b). 27 Fig. 3 Double-ended Carisolv hand instrument tips. Carisolv instruments The manufacturer of Carisolv introduced a set of non-cutting tip instruments in order to increase caries removal efficiency and provide maximum conservation of the residual caries-affected dental Australian Dental Association

6 Chemomechanical caries removal methods tissue (Fig. 3). 25,26 The non-cutting tip has a 90 edge that allows a simple scraping movement for caries excavation which cannot be achieved with conventional spoon excavators that cut the dentine in one direction using a scooping motion. 26 There was an attempt by Meller et al. 28 to use soft microbrushes mounted on a low-speed handpiece for speeding up the caries excavation process. However, they found this method was not effective and took a longer time compared to the manufacturer s recommended instruments. Recently, the Carisolv manufacturer has introduced a preset Carisolv treatment programme into an electronic endodontic motor PowerDrive (Medi Team Dentalutveckling AB). This uses a specially designed handpiece with non-cutting tip burs operated in a similar manner to a conventional slow-speed handpiece. The manufacturer claims that this method has a much greater control of tissue removal at very low sound and vibration levels. 26 However, until now no study has been published that supports the manufacturer s claims regarding efficacy of the caries excavation with such rotary tips. Recently, a cooperative arrangement took place between the bur manufacturer, Komet (Komet, Dental-Gbr Brasseler GmbH & Co, Lemgo, Germany) and the Carisolv manufacturer to establish the New Carisolv system TM (Fig. 2c). The new system contains two types of slow-speed bur, a ceramic (Cera-bur) and polymer (Polymer-bur), designed for removing the softened Carisolv-treated carious dentine. The aim is to significantly reduce the caries excavation time, while ensuring that overexcavation is avoided. It is too early to know whether such claims can be substantiated; however, it may enhance the effectiveness of caries removal. Biological effects of Carisolv on the pulp and dental hard tissue Many studies have evaluated the effect of the direct application of Carisolv gel on exposed pulpal tissue, mostly using a rat model All have reported that Carisolv gel has no adverse effects on the dental pulp and interestingly, some mentioned that Carisolv has a similar action as Ca(OH) 2 pulp capping materials. 30,33 Moreover, it was reported that Carisolv has bactericidal and haemostatic effects on exposed pulp tissue, which is attributed to the alkaline ph of Carisolv of ,33 Furthermore, histological findings showed Carisolv caused minimal superficial necrosis at pulp exposure sites, an effect which could promote the repair function of the injured pulp. 30,31 Only Bulut et al. 33 used human pulp tissue; the teeth used were maxillary and mandibular premolars planned to be extracted for orthodontic purposes. The rationale of using human dental pulp tissue was because the repair capacity of rat pulp tissue, due to its continuous growth, is higher than that of human pulp tissue. 33,34 However, the results of Bulut et al. 33 were in total agreement with the previous animal studies. Many studies have reported that Carisolv gel has no adverse effect on the mineral content of dentine Sakoolnamarka et al. 38 and Hamama et al. 39 reported that the Ca:P ratio of residual dentine following Carisolv removal of carious dentine did not significantly differ from the Ca:P ratio of sound dentine. This may imply that Carisolv is an effective method of removing caries-infected dentine. 25,36,40,41 Scanning electron microscope observations of the dentine surface following Carisolv treatment showed that the excavated surface has an irregular surface topography and was also partially covered with a smear layer. 39,41 45 The majority of studies have reported that the hardness of residual dentine following Carisolv treatment was lower than the hardness of residual dentine following conventional caries removal methods. 39,41,46 Furthermore, it was found that the hardness of the residual dentine gradually decreased towards the caries excavation edge. 38,39 Based on these findings, Magalhaes et al. 46 concluded that Carisolv chemomechanical caries removal method seemed to be less effective in caries removal than conventional rotary methods. However, Sakoolnamarka et al., 38 correlating hardness values to the Ca:P ratio, concluded that Carisolv seemed to be an effective method in preserving cariesaffected dentine, but usually showed lower hardness values. 39,47,48 Thus, the Carisolv method is considered more conservative of tooth tissue. Caries excavation time Two studies demonstrated the original Carisolv gel exhibited prolonged caries excavation times; min (control: rotary min) 25 and min (control: rotary min). 49 In 2004, the new Carisolv gel was introduced after several attempts to improve the efficiency of the gel and reduce the excavation time. 27 Fure and Lingstr om 27 compared the caries excavation time of the original and new Carisolv gels and reported there was no significant difference in moderately-sized carious lesions; (new gel min vs original gel: min; p > 0.05). Conversely, in deep lesions, the new gel exhibited a shorter mean excavation time compared with the original gel; (new gel: min vs original gel min; p < 0.05). However, Fure and Lingstr om did not provide a logical explanation for these findings. 27 Subsequent studies, including the Fure and Lingstr om study, 27 reported that Carisolv chemomechanical caries removal is considered as a time-consuming method compared with conventional rotary methods. A recent study 39 showed that the relatively longer excavation time using Carisolv may be attributed to the number 2014 Australian Dental Association 451

7 H Hamama et al. of times the gel has to be applied; usually in the order of six, to remove the carious lesion. The end-point is when the gel no longer becomes turbid (Fig. 4). Other uses of Carisolv Carisolv gel can be used for other purposes not related to caries excavation, e.g. treatment of oral ulcers, 50 periodontal therapy, 51,52 cleaning of organic debris prior to application of pit and fissure sealants, 53 plaque removal 54 and root canal irrigation. 55 Enzyme-based chemomechanical caries removal agents At the time of writing, there are two products representing enzyme-based chemomechanical caries removal agents. However, at present, only one is commercially available, which is Papacarie TM (papain-based gel, Formula & Acao, Sao Paulo, Brazil) while the other agent, Biosolv TM (SFC-V gel, 3M-ESPE AG, Seefeld, Germany), remains an experimental material. 46,56 Papacarie Papacarie is a Portuguese word meaning caries eater. Papacarie gel was introduced in 2003 by Bussadori et al., 56 and consists of papain enzyme, chloramine, toluidine blue, salts, preservatives, a thickener, stabilizers and deionized water (Fig. 5). 53 Although Papacarie contains a small amount of chloramine, the main action depends on the presence of the papain enzyme. The chloramine was added to enhance removal of denatured tissues. 56,57 Papain is a proteolytic enzyme with bactericidal and anti-inflammatory actions. 6 It is extracted from the latex of leaves and fruits of the green adult Carica papaya tree, which is cultivated in tropical regions such as Brazil, India, South Africa and Hawaii. 58 The manufacturer recommends using the back of a blunt spoon excavator during caries excavation; however, good results have been reported when using the No. 4 Carisolv hand instrument 39 (Fig. 3). Further studies are needed to compare the efficiency of both instruments in conjunction with the Papacarie caries removal method. Mechanism of action The precise mechanism of action of the enzymebased caries removal agents remains unclear, thus further investigations are needed. Bussadori et al. 56 reported that the enzymatic method was based on the fact that infected carious tissues have lost the antiprotease, a-1-anti-trypsin. However, a recent study by Bertassoni and Marshall 59 reported that, until now, there is no evidence that a-1-anti-trypsin could be identified in dentine. Also, it was reported that the papain enzyme could partially degrade intact non-mineralized type I collagen fibrils from rat tail tendon. 59 Furthermore, papain has been shown to reduce the mechanical properties of intact mineralized dentine as a result of degradation of proteoglycans of the matrix, suggesting that the action of papain might be non-specific. 59 Biological effects of Papacarie on the pulp and dental hard tissue At present, there is only one study that has evaluated the effect of Papacarie gel, which was on cultured (a) (b) (c) (d) (e) (f) Fig. 4 Chemomechanical caries removal procedures using Carisolv gel (Medi Team Dentalutveckling AB, Sweden). (a) Dentinal caries lesion. (b) The carious lesion was treated with Carisolv gel and left for 30 seconds prior to excavating the dentine. (c) Excavation of the caries using Carisolv non-cutting instruments (Medi Team Dentalutveckling AB, Sweden) until the gel becomes cloudy and then rinsed-off with distilled water for 20 seconds. (d) The same process was repeated until successive application of the gel failed to become cloudy. (e), (f) Post-excavation view of the lesion site Australian Dental Association

8 Chemomechanical caries removal methods Fig. 5 Papacarie gel (Formula & Acao, Brazil). fibroblasts and subcutaneous tissue. 60 Although this study has not been conducted on dental pulp tissue, it used the Carisolv gel as a positive control. 60 The authors reported that Papacarie was biocompatible and exhibited similar in vitro cytotoxicity and animal implantation assays as Carisolv gel. 60 Although the results of this study showed no adverse effects, further animal studies are needed to evaluate the effect of Papacarie on dental pulp tissue. Furthermore, only two studies have evaluated the effect of Papacarie gel on the mineral content of deciduous 37 and permanent 39 residual dentine using atomic absorption spectrophotometry and energy dispersive X-rays respectively. The results of both studies revealed that Papacarie gel has no adverse effect on the mineral content of the residual dentine. 37,39 Caries excavation time Few clinical trials and laboratory studies 39,64,65 have evaluated Papacarie caries excavation time and most studies compared the results with rotary and Carisolv caries excavation methods. All of these studies reported that there was no significant difference in caries excavation time between Papacarie and rotary caries excavation methods. Moreover, Papacarie exhibited significantly shorter excavation times than Carisolv. 39,63,65 Biosolv Biosolv (SFC-V and SFC-VIII, 3M-ESPE AG, Seefeld, Germany) is a new experimental enzymatic chemomechanical caries removal agent. The information about Biosolv remains very limited and is based mainly on the manufacturer s claims. In 2006, Clementino- Luedemann et al. 66 evaluated SFC-V solution and comparing the results with Carisolv, reported that the SFC-V solution was not as effective as Carisolv. Since 2010, Banerjee et al. 45 and Neves et al. 67,68 evaluated the efficiency of caries excavation of two improved versions of SFC-V and SFC-VIII gels. However, no details about the difference were provided. 67,68 Biosolv instruments Clementino-Luedemann et al. 66 mentioned that the Biosolv developer recommends the use of special plastic instruments (Star V1.3) with their system. The hardness of these instruments is purportedly between the hardness of sound and infected dentine. 66 Moreover, they reported that Star V1.3 instruments were not efficient in caries excavation with Carisolv gel, but they did not clearly state its effectiveness with Biosolv gel. In recent studies of Biosolv, caries excavation was performed with a metal spoon excavator. 45,67,68 Neves et al. 67 reported that the best caries excavation results were obtained using metallic instruments in conjunction with the Biosolv system. Mechanism of action The Biosolv gel is not commercially available however, based on the manufacturer information, it consists of pepsin enzyme in a phosphoric acid/sodium biophosphate buffer. 66,67 It is claimed that the phosphoric acid can dissolve the inorganic components of caries-infected dentine, while permitting the pepsin to selectively disrupt the dentured collagen fibres. Meanwhile, this softened mass can then be easily removed by the specially designed plastics instruments without affecting sound tissue. Effectiveness of Biosolv in caries excavation The limited published data about the effectiveness of Biosolv gel are confusing and tend to be contradictory. Banerjee et al. 45 reported that Biosolv gel caries removal tends to leave more caries-infected dentine compared to Carisolv and hand excavation methods. They attributed this action to the rapid buffering action of dentine on the Biosolv gel, which interferes with the selective function of pepsin on denturated collagen fibres. Conversely, Neves et al. 68 reported that Biosolv is the most aggressive chemomechanical caries removal gel due to its acidity, which can affect both sound and caries-infected dentine. They also reported that the manufacturer attributed this nonselective function to an artefact in the preparation of the thickening agent of the experimental SFC-V gel. This artefact increases the flowability of the gel, and consequently increases the penetration into the sound dentine. 67,68 It is still too early for this experimental product to be applied clinically. Further studies are needed for a better understanding of its mode of action and effectiveness in caries excavation. Clinical aspects of chemomechanical caries removal In general, the majority of clinical studies conducted on Caridex (GK-101E), Carisolv and Papacarie showed a positive attitude of patients toward this type of treatment. Patient satisfaction rates for the Caridex system were 78 93%, 17,19,69,70 and it was reported that Caridex significantly reduced the need for local anaesthesia compared with conventional caries removal methods. 10,17,18,21 The patient satisfaction rates of Carisolv use ranged between 70% to 90%, 25,71 73 and also 2014 Australian Dental Association 453

9 H Hamama et al. showed marked reduction for the need for local anaesthesia. 74 However, some studies have reported negative feedback with regard to the unpleasant taste and odour of Carisolv. 27,49,75 Several studies have evaluated the pain response and patient satisfaction rate after Papacarie treatment. 62,63,76,77 Kochhar et al. 59 reported, using a Visual Analogue and Verbal (VAV) scale, that the least pain was associated with the Papacarie caries excavation method, followed by Carisolv, while the highest pain response was observed in both hand and rotary caries excavation methods. Moreover, Singh et al. 63 reported that Papacarie exhibited a high patient comfort level compared to a rotary caries excavation method using the Wong Baker Faces Pain (WBFP) scale. They attributed this to the selective action of Papacarie on caries-infected dentine without affecting the sound dental tissue. Much more clinical work is needed to determine whether these methods influence restoration survival rates. CONCLUSIONS Based on existing evidence, it can be concluded that the currently available chemomechanical caries removal methods can be considered as a viable alternative to conventional rotary caries removal methods. These methods could be extremely useful in very anxious, disabled and paediatric patients. The concern of the long excavation time of Carisolv gel should be considered during the selection of this caries removal method. REFERENCES 1. Murdoch-Kinch CA, McLean ME. Minimally invasive dentistry. J Am Dent Assoc 2003;134: Kornblit R, Trapani D, Bossu M, Muller-Bolla M, Rocca JP, Polimeni A. The use of Erbium:YAG laser for caries removal in paediatric patients following minimally invasive dentistry concepts. Eur J Paediatr Dent 2008;9: Rainey JT. Air abrasion: an emerging standard of care in conservative operative dentistry. Dent Clin North Am 2002;46: Koubi S, Tassery H. 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11 H Hamama et al. 72. Nadanovsky P, Cohen Carneiro F, Souza de Mello F. Removal of caries using only hand instruments: a comparison of mechanical and chemo-mechanical methods. Caries Res 2001;35: Dammaschke T, Stratmann U, Mokrys K, Kaup M, Reiner Ott KH. Reaction of sound and demineralised dentine to Carisolv in vivo and in vitro. J Dent 2002;30: Peric T, Markovic D, Petrovic B. Clinical evaluation of a chemomechanical method for caries removal in children and adolescents. Acta Odontol Scand 2009;67: Maragakis GM, Hahn P, Hellwig E. Clinical evaluation of chemomechanical caries removal in primary molars and its acceptance by patients. Caries Res 2001;35: Bussadori SK, Guedes CC, Bachiega JC, Santis TO, Motta LJ. Clinical and radiographic study of chemical-mechanical removal of caries using Papacarie: 24-month follow up. J Clin Pediatr Dent 2011;35: Bussadori SK, Guedes CC, Hermida Bruno ML, Ram D. Chemo-mechanical removal of caries in an adolescent patient using a papain gel: case report. J Clin Pediatr Dent 2008;32: Address for correspondence: Professor Michael Burrow Melbourne Dental School Faculty of Medicine, Dentistry and Health Sciences The University of Melbourne Melbourne VIC mfburrow@unimelb.edu.au Australian Dental Association