Evaluation of Denture Base Adaptation Fabricated Using Conventional, Subtractive, and Additive Technologies: A Volumetric Micro‐Computed Tomography Analysis

Abstract

Purpose An in vitro study to compare the adaptation of denture bases fabricated with 4 different techniques using volumetric 3‐dimentional (3D) analysis. Material and Methods Edentulous maxillary and mandibular casts were scanned, and standardized denture bases were designed using CAD design software. The same standard tessellation language (STL) data were used to produce the denture bases with 4 different fabrication methods: compression molding (CM), injection molding (IM), PMMA milling (PM), and 3D printing (3D) (n = 11/group). Milled wax denture bases were used to fabricate CM and IM groups. Denture bases placed on edentulous casts were scanned using micro‐computed tomography (micro‐CT). Volumetric gap between denture base and cast was calculated from 6 locations for maxilla (anterior ridge crest, posterior ridge crest, labial vestibule, buccal vestibule, palate, and posterior palatal seal) and 3 locations for mandible (intermolar, molar, and retromolar) in addition to overall gap measurements for edentulous arches. The data were analyzed with factorial analysis of variance (ANOVA), 1‐way ANOVA, and post‐hoc Duncan tests. Reproducibility of fabrication methods with regard to each location was assessed using Z test (α = 0.05). Results In the maxilla, the highest and lowest palatal gap measurements were recorded for CM (898.44 ± 87.73 mm3) and PM (357.16 ± 57.68 mm3) (p = 0.05). The highest gap measurements for CM and 3D were at palate and, for IM and PM were at posterior ridge crest. In mandible, the volumetric gap measurements for CM were the highest and for PM were the lowest irrespective of location (p = 0.05). PM group showed the best reproducibility and adaptation with the lowest overall mean gaps for both edentulous arches (p = 0.05). Conclusions Denture bases milled from PMMA blocks showed better adaptation than 3D printed, or wax milled and conventionally fabricated denture bases for both maxillary and mandibular arches. PMMA milling is a reproducible technique that enables the construction of accurate dentures. Clinicians should be cautious about the palatal gap when the compression molding technique is used. Micro‐CT is a valid technique for evaluating the denture base adaptation.

Comparison of adaptation accuracy between three different denture base materials for the completely edentulous upper arch. An invitro study.

“…The patterns of distortion as presented by gap distance in the three groups also come in accordance with other studies that showed that the greatest distortion occurs in the mid-palatal region due to the linear rather than volumetric shrinkage that results in the pull of the material away from the cast 9,11,22,24 . This could have a clinical significance not only on denture retention, but also on longevity of the denture considering that upper denture fracture occurs most commonly in the mid-palatal region and is mainly due to poor fit 25,26 .…”

The Trueness of Obturator Prosthesis Base Manufactured by Conventional and 3D Printing Techniques

“…In addition, the highest volumetric gap between the denture base and cast was observed in the compression molding and 3D printing groups at the palatal region. 28 Color maps from this present study also showed the Compression Molding group had positive discrepancies at the mid-palatal and maxillary defect areas. The Cara Print 3D-Printer and Carbon 3D-Printer groups had negative discrepancies at the palatal area and maxillary defect.…”

“…The results from this study agree with Oguz et al, where they compared the intaglio surface adaptation of complete dentures fabricated with compression molding, injection molding, 3D printing, and milling techniques. 28 For the maxillary denture, injection molding produced more accurate denture base adaptation than the 3D-printing technique (The Vida; EnvisionTEC and E-Denture; EnvisionTEC) did. In addition, the highest volumetric gap between the denture base and cast was observed in the compression molding and 3D printing groups at the palatal region.…”

Digital Workflow for Establishing the Posterior Palatal Seal on a Digital Complete Denture

“…Moreover, a deformation of the printed denture may occur when demounting the partially polymerized denture from the build platform 18 . Studies have shown that 3D printed dentures have similar space from the tissue surface at the PPS area as conventionally fabricated CDs 29 …”