European Study on Three Different Approaches to Managing Class 2 Cavities in Primary Teeth

The purpose of this randomized clinical trial is to compare the clinical effectiveness of three treatments involving different caries management strategies (conventional restorations, Hall technique, and Non-Restorative Caries Treatment) to the management of class II carious primary molars in children (3-8 year-old).

At present, many materials and techniques are used to treat carious primary teeth. All of these have their proponents who claim they provide the best performance in terms of longevity, aesthetics, bio-compatibility, etc (Qvist, 2010; Yengopal et al., 2009). However, despite the great variety of techniques and materials, there is no definite evidence for the most effective approach when dental caries in primary molars is concerned, as yet. On the other hand, there is conclusive evidence that shows that glass-ionomer cement is an inappropriate material for class II restorations in primary teeth, due to its significant shorter longevity compared with other restorative materials like compomer and amalgam. Recently, there is re-surging interest in more biological (less-invasive) techniques: such as the Non-Restorative Caries Treatment (Peretz & Gluck, 2006; Gruythuysen et al., 2010) or stainless steel crowns with the advent of the Hall technique in Scotland (Innes et al., 2007). However, there is lack of comparative evidence from high quality clinical trials leading to uncertainty in the effectiveness of these techniques. In addition, these techniques are rarely compared with standard fillings.

Class II carious primary molar, Non-Restorative Caries Treatment, Hall Technique, Conventional restorations, Children

This technique uses preformed Stainless Steel Crowns (SSCs) to restore carious primary molars. Local anaesthesia, caries removal or tooth preparation are not required.

This is a less operative approach, here carious lesions are opened removing the overhanging enamel and making the cavity accessible for biofilm removal. No carious dentine will be removed from the pulpal wall and no local anaesthesia will be placed. Fluoride varnish (Duraphat ®) will be applied to the cavity. Parents/children will be trained to clean the cavity by brushing using a buccolingual technique.

This technique corresponds to the conventional way of treating cavitated carious lesions involving complete caries removal, use of local anaesthesia (when needed), and a compomer (Dyract ®) restoration. Cotton wool roll isolation and continuous aspiration will be used.

Technique: Removal of dental plaque and rest of aliments from the cavity Selection of the SSC If the contact points are very tight, orthodontic separator elastics could be placed through the mesial and distal contacts and the SSC has to be fitted at a subsequent appointment Dry the crown and fill with glass-ionomer luting cement Place the crown over the tooth Removal of cement excesses from the crown margins The child should be asked to keep biting on the crown until the cement has set

Technique: A high-speed bur should be used to remove the undermined enamel and make the cavity accessible for plaque removal. Do not remove the contact area Clean, dry the cavity and apply Duraphat® varnish fluoride (50/mg/ml) Show the cavity to patient/parents and give them tooth-brushing instructions Tell to parents that good plaque control is the key for this treatment The recall interval for these patients is every 3 months.

Technique: Local anesthesia should be used when needed Perform complete caries removal and cavity preparation Use a matrix band and a wedge to tightly hold the band against the tooth Place the material (Compomer) Check contacts and occlusion, and polish the restoration

Failure rate of the three treatment arms judged clinically after 2 years such as clear caries progression, secondary caries, loss of restoration, reversible pulpitis treated without requiring pulpotomy

Number of children experiencing irreversible pulpitis, dental abscess, or extraction judged clinically after 2 years

Child's oral health status as assessed by the gingival status and bacterial plaque index judged clinically after 1 and 2 years

Behaviour of children during treatment was assessed using the Frankl Behavior Rating Scale. It is a four-point scale (definitely negative, negative, positive, definitely positive. This scale ranges from definitely negative behaviour, when the child refuses the treatment (worse outcome) to definitely positive behaviour (best outcome), when the participant is completely cooperative. In this scale a score is not reported, thus categories are not converted into numerical data.

Child's perception of pain intensity during treatment was assessed using the Visual Analogue Scale of Faces. It is a five-point scale (1 to 5), which includes five faces of children representing from very light to very intense pain (very low, low, moderate, intense, very intense), with higher scores representing worst outcomes (pain) and low scores best outcomes (no pain). Participants were asked to select the face that represents how he/she felt during the procedure.

Inclusion Criteria: - Children aged 3-8 years who attend the Preventive and Paediatric Department of Greifswald University, Germany. (Lithuania: children who attend the paediatric dentistry department, Dental Faculty, Lithuanian University of Health Sciences) At least one primary molar tooth with caries into dentine involving two dental surfaces (diagnosed according to the International Caries Detection and Assessment System [ICDAS], codes 3 to 5) Willing to be examined Exclusion Criteria: Clinical or radiographic signs of pulpal or peri-radicular pathology Patients with a systemic disease requiring special considerations during their dental treatment. Parents/children who refuse to participate in the study

Ernst-Moritz-Arndt-Universität Greifswald. Dental Faculty, Preventive and Paediatric Dentistry Department

University of Dundee, Dentistry & Nursing , College of Medicine, Unit of Dental and Oral Health School of Dentistry

Santamaria RM, Innes NP, Machiulskiene V, Evans DJ, Splieth CH. Caries management strategies for primary molars: 1-yr randomized control trial results. J Dent Res. 2014 Nov;93(11):1062-9. doi: 10.1177/0022034514550717. Epub 2014 Sep 12.

Santamaria RM, Innes NP, Machiulskiene V, Evans DJ, Alkilzy M, Splieth CH. Acceptability of different caries management methods for primary molars in a RCT. Int J Paediatr Dent. 2015 Jan;25(1):9-17. doi: 10.1111/ipd.12097. Epub 2014 Mar 7.

Santamaria RM, Innes NPT, Machiulskiene V, Schmoeckel J, Alkilzy M, Splieth CH. Alternative Caries Management Options for Primary Molars: 2.5-Year Outcomes of a Randomised Clinical Trial. Caries Res. 2017;51(6):605-614. doi: 10.1159/000477855. Epub 2017 Dec 20.