Comparison of denture space and patient satisfaction for neutral zone versus standard-designed digital dentures restoring mandibular resorbed ridges: A crossover randomized clinical trial.

PURPOSE: To compare neutral-zone-designed and standard-designed digital complete dentures used to restore severely resorbed ridges through differential digital analysis of teeth arrangement position, shape of the polished surface, and assessment of patient satisfaction.

MATERIALS AND

METHODS

This study applied a within-subject comparison of two denture forms: computer-aided design and computer-aided manufacturing (CAD-CAM) dentures designed based on the bone-support concept (control group) and CAD-CAM dentures designed based on the neutral-zone concept (test group). Twelve completely edentulous patients exhibiting advanced ridge atrophy were recruited, and they were randomly assigned to use one of the two dentures before the other. A comparison between the two groups' virtual denture confines was conducted using "Medit compare" digital software. The average values of three-dimensional deviations between the two dentures at different regions were calculated. The "patient denture assessment" questionnaire was used to gauge participants' satisfaction with their dentures. The obtained scores were used to compare the two denture types.

RESULTS

The position of the neutral zone was significantly shifted at the level of both denture teeth and denture base outer limits (p = 0.001). The greatest deviation was calculated at the region of the palatal polished surface followed by lingual flange contours, while the buccal flanges displayed the least deviations (p ≤ 0.05). Statistically significant differences were observed between patients' satisfaction with neutral zone and standard dentures regarding function and comfort, retention, and stability of lower dentures (p ≤ 0.05).

CONCLUSION

CAD-CAM neutral-zone dentures have distinctly different anatomical confines that can be clinically correlated to their better impact on patient acceptance.