Introduction:

The accuracy of guided implant placement relies heavily on the trueness and dimensional stability of 3D-printed surgical guides. 

Post-printing factors can induce polymer relaxation or continued curing, thereby altering surgical guide accuracy: ambient light, water/humidity, and time. Variability in surgical guide stability may result in discrepancies between planned and actual implant positions. 

AIM: To understand how different storage conditions affect dimensional changes of surgical guide material in order to optimize clinical reliability

Methods:

60 standardized surgical guide prototypes were printed using a HeyGears A2D 4K printer (DLP) and post-processed. 

Samples were stored under 4 conditions (n = 15): 

1. Dry/UV-Blocked (DU)

2. Dry/Ambient (DA)

3. Wet/Ambient (WA)

4. Wet/UV-Blocked (WU)

 

Results:

Divided into RMS estimates calculating 3D deviation and angle deviation calculation between the guides.

Statistics: Two-way repeated-measures ANOVA with Tukey HSD post-hoc tests (α = .05) assessed effects of group and time.

RMS Estimate Difference: Significant effects for group (F = 22.61; P < .001), time (F = 15.10; P < .001), and interaction (F = 18.55; P < .001). The Dry/UV-Blocked group maintained the most stable RMS values throughout the 14 days.

Angle Deviation: Significant main effects of group (F = 13.95; P < .001) and time (F = 5.54; P = .0003), and a significant interaction (F = 2.68; P = .002). The Dry/UV-Blocked group consistently had the lowest deviation across all time points.

Trend: Stability decreased under wet and/or ambient light conditions, with Wet/UV-Blocked showing the greatest deviation over time.

 

Conclusion:

Dimensional stability of 3D-printed surgical guides is significantly influenced by storage condition and elapsed time after post-processing.

1. Dry, UV-blocked storage demonstrated the lowest RMS estimates and angle deviations, maintaining superior accuracy over 14 days. 

2. Wet and light-exposed conditions promoted progressive dimensional distortion. 

3. Clinically, dry, UV-blocked storage is recommended for maintaining surgical guide accuracy before implant placement.