Photobiomodulation (PBM) has shown promising effects in managing postoperative pain following conventional periapical surgery, although current evidence remains limited. This study aims to assess the effect of PBM on postoperative pain 24 hours after periapical surgery.

A randomised, controlled, double-blind trial will include 34 patients undergoing periapical surgery in the maxillary region, randomly assigned to an experimental group (n=17) or control group (n=17). The experimental group will receive PBM (GaAlAs diode laser, 808 nm, 100 mW, 4 J/cm², applied at five vestibular points) and placebo ibuprofen immediately and 24 hours postoperatively. The control group will receive simulated PBM and active ibuprofen. The primary outcome is postoperative pain assessed by the visual analogue scale at 24 hours. Secondary outcomes include pain at the seventh day, paracetamol intake, oedema, ecchymosis, soft tissue status and temperature at 24 hours and 7 days. Radiographic evaluation of healing will be performed at 1 and 3 months. Statistical analysis will be conducted based on data distribution, using repeated measures ANOVA (Analysis of Variance) or non-parametric equivalents for longitudinal outcomes, and appropriate tests for categorical variables. Significance will be set at p

The study was approved by the Human Research Ethics Committee of Universidad Católica del Uruguay (process no. 220914). Results will be disseminated to participants, healthcare professionals, the public and scientific communities.

NCT05935306.

Colorectal cancer (CRC) is the third most common cancer and the second leading cause of cancer mortality worldwide. Despite the organised CRC screening programme, the uptake rate of the population-based CRC screening was still low. Thus, we will conduct a randomised controlled trial in a community setting to evaluate the effectiveness of a theory-based chatbot in promoting CRC screening uptake.

A total of 500 eligible participants will be randomly assigned to a WhatsApp Messenger-initiated chatbot outreach group or a standard text reminder group at a ratio of 1:1. The intervention group will deliver Chinese culturally tailored education texts and videos developed based on the Health Belief Model and the Trans-Theoretical Model. The control group will deliver a standard text reminder of information about the Hong Kong organised CRC screening programme. In addition to the baseline assessment and postintervention assessment, all subjects will be followed up for 3 months and 6 months, respectively. The primary outcome will be the CRC screening uptake rate at the 3 month and 6 month follow-up. The secondary outcomes will be the intention to undergo CRC screening uptake, time interval to participate in and complete screening after recruitment, and reasons for not participating in screening at the 3 month and 6 month follow-up. Quantitative data will be analysed using Student’s t-test, Pearson’s ² test or Fisher’s exact test. Qualitative data will be analysed by thematic analysis.

Ethical approval of this trial was granted by the Joint Chinese University of Hong Kong-New Territories East Cluster Clinical Research Ethics Committee (2022.614). Written informed consent will be obtained from study participants before enrolment. The findings will be disseminated through peer-reviewed journals.

The study was registered on clinicaltrials.gov (NCT06192862).