An in vitro assessment of the residual dentin after using three minimally invasive caries removal techniques

To evaluate the efficiency and effectiveness of three minimally invasive (MI) techniques in removing deep dentin carious lesions. Forty extracted carious molars were treated by conventional rotary excavation (control), chemomechanical caries removal agent (Brix 3000), ultrasonic abrasion (WOODPECKER, GUILIN, China); and Er, Cr: YSGG laser ablation (BIOLASE San Clemente, CA, USA). The assessments include; the excavation time, DIAGNOdent pen, Raman spectroscopy, Vickers microhardness, and scanning electron microscope combined with energy dispersive X-ray spectroscopy (SEM-EDX). The rotary method recorded the shortest excavation time (p < 0.001), Brix 3000 gel was the slowest. DIAGNOdent pen values ranged between 14 and 18 in the remaining dentin and laser-ablated surfaces recorded the lowest reading (p < 0.001). The Ca:P ratios of the remaining dentin were close to sound dentin after all excavation methods; however, it was higher in the ultrasonic technique (p < 0.05). The bur-excavated dentin showed higher phosphate and lower matrix contents with higher tissue hardness that was comparable to sound dentin indicating the non-selectiveness of this technique in removing the potentially repairable dentin tissue. In contrast, the MI techniques exhibited lower phosphate and higher organic contents associated with lower microhardness in the deeper dentin layers. This was associated with smooth residual dentin without smearing and patent dentinal tubules. This study supports the efficiency of using MI methods in caries removal as conservative alternatives to rotary excavation, providing a promising strategy for the clinical dental practice.

Efficiency of ER:YAG laser therapy in combination with behaviour management technique in reducing anxiety among paediatric dental patients - a study protocol for a randomised clinical trial

INTRODUCTION

When providing dental care to children with a high level of dental anxiety, the range of approaches is divided into two sections: use of behaviour management techniques (BMTs) and application of alternative methods for caries removal. In an attempt to reduce dental anxiety, they can be mixed and matched in accordance with the dentists' choice. Owing to its promoted advantages, erbium-doped yttrium aluminium garnet (Er:YAG) laser turns into an ideal alternative technique for hard dental tissue therapy in anxious paediatric patients. The aim of the study is to assess the efficacy of a modified version of the BMT 'Latent inhibition' in combination with Er:YAG laser for achieving a reduction of dental anxiety in paediatric dental patients.

METHODS AND ANALYSIS

This is a protocol for a randomised controlled clinical trial. The participants will be children aged 6-9 years, requiring conservative treatment of occlusal carious lesion on a second primary molar. Patients will be randomly assigned to the experimental or control group via a computer-generated sequence. In both groups, 'Latent inhibition' will be used as an anxiety-management technique. In the experimental group, caries treatment will be performed with Er:YAG laser, whereas that in the control group it will be performed with conventional rotary instruments. Outcome measures will be dental anxiety felt before and after the treatment, reported by the patient on a modified version of the Faces Scale by LeBaron et al., and the dynamics of heart rate, registered during the treatment session, which will be measured with a mobile pulse oximeter. Data will be analysed by independent sample t-test and paired t-test (p˂0.05).

ETHICS AND DISSEMINATION

The study protocol has been approved by the Committee for Scientific Research Ethics, Medical University-Plovdiv, Bulgaria (reference number P-2839, protocol of approval number 3/30.04.2015) and registered on a publicly accessible database. This research received institutional funding from the Medical University-Plovdiv, Bulgaria. The results will be presented through peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

NCT04924452.