Scientific Rationale
Tooth extraction is one of the most frequently performed dental procedures. Despite its routine nature, poor comprehension of post-operative instructions may lead to complications such as alveolar osteitis, infection, or delayed wound healing. Evidence from health communication research shows that patients retain only a small proportion of verbal-only instructions, particularly in settings of heightened anxiety. Multimedia learning theory (Mayer, 2021) suggests that simultaneous delivery of verbal, visual, and kinesthetic information enhances encoding and recall.
Building on this theory, the Post-Dental Extraction Care Kit (PDEC-kit) was developed. It integrates audiovisual, pictorial, and demonstration-based teaching into a structured package that supplements standard verbal guidance. The central hypothesis is that the PDEC-kit improves knowledge retention, compliance, and anxiety outcomes compared to verbal instructions alone.
Study Design Overview
This is a prospective, single-centre, two-arm, parallel-group randomized controlled trial. Participants are assigned to intervention or control groups in a 1:1 ratio. Allocation concealment was ensured using block randomisation with opaque, sequentially numbered envelopes. Operators performing extractions were blinded to allocation.
The sample size was determined by a priori power analysis using G\*Power 3.1, based on a medium effect size (f = 0.25), α = 0.05, power = 0.80, and repeated measures across two groups. The minimum required sample was 86; recruitment was increased to 208 to account for attrition.
Intervention Details
Control arm: Standardised verbal post-extraction instructions delivered by a single calibrated investigator to minimise variability.
Intervention arm: Same standardised verbal instructions plus the PDEC-kit, which consists of:
Educational video (2 minutes): Demonstrates correct gauze placement, oral hygiene, and activity restrictions.
Illustrated flashcards: Show simplified dos and don'ts using pictorial reinforcement.
Live model demonstration: Gauze placement demonstrated on a dental model for kinesthetic learning.
Bilingual brochure (English and Bahasa Melayu): Provides at-home reference; a QR code enables access to a digital version.
All components were pilot-tested for clarity and developed by a multidisciplinary panel of oral surgeons, dental educators, and communication specialists.
Assessment Schedule
Data collection was performed at three points:
T0: Baseline (pre-extraction) - demographic data, knowledge baseline, and anxiety baseline.
T1: Immediately after instruction - post-intervention knowledge and anxiety assessments.
T2: One-week follow-up via telephone - reassessment of knowledge retention, anxiety, compliance, and complications.
Measurement Instruments
Knowledge retention: Four-item structured quiz (binary scoring).
Dental anxiety: Index of Dental Anxiety and Fear (IDAF-4C+, validated Malay version).
Compliance: Structured checklist covering analgesic use, diet, hygiene, activity, and smoking behaviour.
Pain: 10-point Likert scale.
Complications: Self-reported bleeding, infection, or alveolar osteitis, confirmed by clinic review where indicated.
Analytic Framework
Data were analysed using SPSS v29. Statistical procedures included:
Descriptive statistics for demographic and baseline variables.
Independent-samples t-test for between-group comparisons.
Paired-samples t-test for within-group pre-post changes.
Repeated measures ANOVA (Greenhouse-Geisser correction applied when sphericity violated).
Chi-square test for categorical variables (compliance, complication rates).
Spearman's correlation for anxiety-pain association. Significance threshold: p \< 0.05.
