Comparison between the scavenging efficiency of the Silhouette and Porter Brown breathing systems used in Inhalation Sedation for children.

Title: Comparison between the scavenging efficiency of the Silhouette and Porter Brown breathing systems used in Inhalation Sedation for children. Background: Dental anxiety is a widespread problem in children. Children with dental anxiety frequently require referral to specialist paediatric dentists for treatment. Inhalation-sedation (IHS) using nitrous oxide/oxygen (N2O/O2) mixture is a pharmacological behaviour management technique that is widely used to manage dental anxiety in children. There have been some reports of occupational chronic exposure to N2O being linked to serious health problems. Therefore, an effective scavenging system is necessary to reduce nitrous oxide levels in the surrounding environment, in order to reduce N2O exposure of dental team professionals. There are a number of different inhalation sedation breathing systems such as the Porter Brown and the Silhouette systems. A previous assessment of the ability of different scavenging systems demonstrated that not all systems are equally effective. Few studies have compared the Porter Brown to other Systems with paediatric patients, but there were no previous studies in the literature showing the effectiveness of the Silhouette system or comparing it to other breathing systems. Aims: This study aimed to investigate the scavenging efficiency and acceptability of the Silhouette breathing system compared to the Porter Brown breathing system, used in inhalation sedation for children. It also aimed to investigate if there was any difference in providing the sedation between the two systems. Method: Children aged 7-15 years of age who were seen at Leeds Dental Institute for dental treatment under inhalation sedation were invited to this study. This study was designed as a randomised non-blinded controlled clinical trial. Children were introduced to both Porter Brown and Silhouette nose pieces in the assessment visit. Recruited children were allocated randomly to one of the two breathing system groups for their dental treatment. The scavenging efficiency of the breathing systems were assessed by measuring the N2O levels in the ambient air using diffusion tubes. The participants’ acceptability was assessed through a feedback questionnaire at the end of their treatment session. Results: A total of 54 children were recruited, 27 participants in each group. An independent-sample t-test showed a statistically significant difference between the two breathing systems based on the N2O exposure levels in the dentist zone (p=0.045). There was a statistically significant difference in head movement in the Silhouette group compared with the Porter Brown. The participants in the Silhouette group found it easier to move their heads to the side. However, mask removal was reported to be more comfortable for the participants in the Porter Brown group. The results showed no statistically significant association between participant age and the comfort of wearing the mask. There were also no statistically significant differences between participant cooperation levels in either group. A statistically significant difference was observed in the anxiety levels before and after the treatment session in female participants. However, this difference was not statistically significant in male participants. Conclusion: Both systems had active scavenging, with N2O exposure levels being less than 100ppm over an 8-hour time period. Both breathing systems were accepted almost similarly.