TITLE : Impact of Intracanal Cryotherapy on Postoperative Pain and Antimicrobial Efficacy in Primary Teeth : A randomized clinical trial

INTRODUCTION

Effective management of postoperative pain and infection is critical in pediatric endodontics, especially for primary teeth undergoing pulpectomy. Conventional irrigation protocols using sodium hypochlorite or chlorhexidine have demonstrated antimicrobial efficacy but often fall short in minimizing postoperative discomfort. Intracanal cryotherapy, the application of cold saline as a final rinse, has emerged as a promising adjunctive technique with demonstrated benefits in adult endodontics, including reduced inflammation, lower pain scores, and improved healing. However, its application and effectiveness in primary teeth remain underexplored.

This randomized clinical trial aims to evaluate the impact of intracanal cryotherapy on postoperative pain and its antimicrobial efficacy in primary molars requiring pulpectomy. Given the unique anatomical and physiological characteristics of primary teeth, such as thinner dentinal walls and complex canal morphology, assessing the efficacy of cryotherapy in this context is essential. Reducing postoperative pain and microbial load can significantly enhance treatment outcomes and cooperation in pediatric patients, thereby contributing to better oral health and quality of life. The results of this study have the potential to inform clinical guidelines and encourage adoption of more child-friendly, minimally invasive endodontic protocols. Through this investigation, we seek to fill a critical gap in pediatric endodontic research and improve evidence-based care for children.

Aims & objective with reason for choosing the proposed Research 

AIM : To evaluate and compare the effect of intracanal cryotherapy on postoperative pain and antimicrobial efficacy during pulpectomy procedure in primary teeth.

OBJECTIVES

•       To assess postoperative pain reduction using intracanal cryotherapy in primary teeth.

•       To evaluate the antimicrobial efficacy of intracanal cryotherapy in primary teeth.

•       To compare outcomes between 20°C - 25°C (ambient room temperature) and   2°C - 4°C (cryotherapy) saline irrigation.

•        

Methodology with sample size

INCLUSION CRITERIA

•        Healthy children of  3 to 7 years whose parents are willing to give informed consent.

•        Children with symptoms of irreversible pulpitis.

•         Single rooted primary tooth with at least 2/3rd of the root length present.

EXCLUSION CRITERIA

•       Children with any systemic disease.

•        Children who have taken antibiotics in the last three month.

•        Teeth nearing  exfoliation.

This randomized controlled clinical trial aims to evaluate the effect of normal saline irrigation at different temperatures on microbial reduction and postoperative pain in pediatric endodontic procedures. A total of 30 pediatric patients requiring pulpectomy in primary molars will be recruited for the study after obtaining informed consent from their parents or guardians. Patients will be randomly allocated into two groups (n = 15 each) using Randomization Allocation Software 2.0.

Group I (Control Group) will receive final irrigation with normal saline at room temperature (25°C to 30°C), while Group II (Experimental Group) will receive cold normal saline (2°C to 4°C) for cryotherapy. Strict aseptic conditions and rubber dam isolation will be maintained throughout the procedure. Standardized access opening and biomechanical preparation will be performed in all cases using a consistent technique and instrumentation.

Microbial samples will be collected at two intervals:

• S1 – immediately after biomechanical preparation (BMP), and
• S2 – after final irrigation with saline at the designated temperature for each group.

Samples will be collected using sterile paper points inserted into the root canal for 60 seconds, and then transferred into sterile vials containing Brain Heart Infusion (BHI) broth. The samples will be incubated at 37°C for 24 hours, and the Colony Forming Units (CFU) will be counted to assess microbial load.

Postoperative pain will be recorded using the Wong-Baker Faces Pain Rating Scale, a validated tool for pediatric pain assessment. Pain levels will be recorded at 6, 24, 48, and 72 hours postoperatively, as reported by the child or guardian.

All data will be subjected to statistical analysis using appropriate tests such as paired t-test, unpaired t-test, or ANOVA, depending on the distribution and variance. A p-value < 0.05 will be considered statistically significant. This study aims to determine whether cryotherapy using cold saline can enhance microbial reduction and reduce postoperative discomfort, thereby improving clinical outcomes in pediatric endodontics.

Expected outcomes& clinical relevance 

EXPECTED OUTCOME-

There will be significant difference in reducing postoperative pain and enhancing  antimicrobial efficacy of intracanal cryotherapy in primary teeth.

CLINICAL SIGNIFICANCE-

•       Postoperative pain and persistent microbial presence are major concerns in pediatric endodontics.

•       Cryotherapy approach emphasizes rapid cooling, gradual thawing and repeated freezing to enhance tissue damage*.

•        Effective strategies that can minimize discomfort and enhance disinfection without increasing treatment time or complexity are essential in managing pediatric patients.

•       Identifying the optimal temperature for cryotherapy may help standardize its clinical use, ensuring maximum patient comfort and improved antimicrobial effectiveness.