Background: The success of complete denture therapy relies on multiple factors, notably the materials used and the fabrication techniques employed. With emerging digital technologies, newer methods such as CAD/CAM milling and 3D printing offer potential improvements over conventional processing. This study aimed to evaluate and compare the material properties and clinical performance of complete dentures fabricated using three different techniques. Methods: A total of 45 maxillary and mandibular dentures were fabricated and categorized into three groups: Group A (conventional heat-cured PMMA), Group B (CAD/CAM milled), and Group C (3D printed). Surface hardness, flexural strength, and dimensional accuracy were tested in vitro. Additionally, 15 edentulous patients (5 per group) were rehabilitated, and clinical fit and patient satisfaction were assessed. Results: Group B (CAD/CAM) demonstrated the highest surface hardness (22.8 HV), flexural strength (95.6 MPa), and dimensional accuracy (58.3 µm RMS error), followed by Group C and Group A. Patient satisfaction scores were also highest for CAD/CAM dentures (mean score 4.8/5), with statistically significant differences among groups (p<0.05). Conclusion: CAD/CAM milled dentures outperformed conventional and 3D printed dentures in both material properties and clinical outcomes. Digital techniques offer promising alternatives for complete denture fabrication.

Complete dentures play a pivotal role in the rehabilitation of edentulous patients, not only restoring mastication and phonetics but also contributing significantly to esthetics and psychological well-being. The success of complete dentures depends heavily on the techniques employed during their fabrication and the material properties of the components used [1]. In recent years, advancements in dental materials science and prosthodontic techniques have transformed the approach to denture fabrication, offering enhanced comfort, durability, and fit.

Traditionally, complete dentures have been fabricated using heat-cured polymethyl methacrylate (PMMA) due to its favorable esthetics, ease of processing, and acceptable physical properties [2]. However, PMMA possesses certain limitations, such as low impact resistance, high residual monomer content, and susceptibility to fracture, particularly in the posterior region [3]. To address these concerns, various modifications and reinforcements have been introduced, including fiber reinforcement, cross-linking agents, and incorporation of nanoparticles [4].

Alongside material innovations, fabrication techniques have also evolved. The conventional method of denture fabrication is labor-intensive, involving multiple clinical and laboratory steps that require precision at each stage [5]. Errors during impression making, bite registration, or acrylic polymerization can compromise the fit and comfort of the prosthesis. In contrast, contemporary techniques such as computer-aided design and computer-aided manufacturing (CAD/CAM) offer enhanced precision, better fit, and reduced chair time [6]. CAD/CAM dentures are milled from pre-polymerized acrylic blocks, resulting in fewer porosities and more consistent polymerization, thus improving mechanical strength [7].

Another critical aspect influencing denture performance is the adaptation of the denture base to the mucosal tissues. Studies have shown that a better-fitting denture base improves retention, stability, and patient satisfaction [8]. Digital workflows allow for improved accuracy in soft tissue capture and reproduction, which translates to better adaptation of the base and improved function [9]. Furthermore, additive manufacturing (3D printing) has also emerged as a promising technique in denture fabrication, offering rapid prototyping and customization, although its mechanical properties are still under evaluation [10].

Despite these advancements, a significant number of dental practitioners continue to rely on conventional techniques due to familiarity, cost-effectiveness, and lack of access to digital infrastructure in certain regions. Therefore, there remains a need to critically evaluate the performance and properties of dentures fabricated by both conventional and digital methods in real-world clinical settings. This study aims to assess and compare various fabrication techniques—including conventional heat-cured, CAD/CAM milled, and 3D-printed dentures—with respect to material strength, surface hardness, dimensional accuracy, and patient-reported outcomes.

1. Surface Hardness

The mean Vickers hardness values showed that Group B (CAD/CAM milled) had the highest surface hardness (22.8 ± 0.6 HV), followed by Group C (3D printed) (19.5 ± 0.5 HV), and Group A (conventional) had the lowest (17.2 ± 0.7 HV). The difference was statistically significant (p < 0.001). Table 1

2. Flexural Strength

Flexural strength was significantly higher in Group B (CAD/CAM) at 95.6 ± 4.3 MPa. Group A (conventional) showed moderate values (76.4 ± 3.8 MPa), while Group C (3D printed) had the lowest strength (61.3 ± 3.5 MPa), with intergroup differences being statistically significant (p < 0.001). Table 2

3. Dimensional Accuracy

The root mean square (RMS) error analysis revealed that Group B had the best adaptation (mean deviation 58.3 ± 6.1 µm), followed by Group C (81.2 ± 7.4 µm), and Group A showed the least accuracy (101.5 ± 8.2 µm), with statistically significant differences (p < 0.001). Table 3

4. Patient Satisfaction and Clinical Fit

Patients rehabilitated with CAD/CAM dentures reported the highest satisfaction scores (mean 4.8/5), followed by 3D printed (4.2/5), and conventional dentures (3.9/5). Denture retention and stability were also superior in CAD/CAM dentures as per Kapur’s index (p < 0.05). Table 4

Table 1: Comparison of Surface Hardness (Vickers Hardness Number - VHN)

                                                *Statistically significant at p < 0.05

Table 2: Flexural Strength of Denture Base Materials

                                               *Statistically significant at p < 0.05

Table 3: Dimensional Accuracy of Denture Base (RMS Deviation in µm)

                                               *Statistically significant at p < 0.05

Table 4: Patient Satisfaction and Clinical Fit Scores

                                    *Statistically significant at p < 0.05

The present study aimed to evaluate and compare the mechanical and clinical performance of complete dentures fabricated using three different techniques: conventional heat-cured PMMA, CAD/CAM milling, and 3D printing. The results revealed statistically significant differences among the groups in terms of surface hardness, flexural strength, dimensional accuracy, and patient satisfaction.

Surface hardness is a key indicator of resistance to wear and scratch, especially in the oral environment where abrasive forces are common. CAD/CAM milled dentures demonstrated superior hardness values compared to both 3D printed and conventional dentures. This can be attributed to the high-density polymerization achieved in industrially pre-polymerized PMMA blocks used for milling [1,2]. In contrast, conventional dentures are prone to internal porosities and residual monomer content, which reduce surface hardness [3,4]. Although 3D printed dentures showed improved hardness over conventional ones, their resin-based materials are still evolving in terms of long-term durability [5].

Flexural strength is vital to prevent midline fractures, a common issue in maxillary dentures. The highest flexural strength observed in CAD/CAM dentures aligns with previous reports suggesting that the milling process reduces internal stresses and voids [6]. The conventional group showed moderate values, consistent with earlier findings on heat-cured PMMA’s moderate resilience [7,8]. The 3D printed dentures exhibited the lowest flexural strength, likely due to layer-by-layer deposition and incomplete polymerization between layers, which create weak interfaces [9].

In terms of dimensional accuracy, CAD/CAM dentures again outperformed the others, consistent with prior literature emphasizing the precision of subtractive manufacturing [10,11]. The lower RMS error in CAD/CAM-fabricated bases enhances tissue adaptation, resulting in improved retention and stability. The conventional group exhibited the highest deviation, likely due to processing errors such as polymerization shrinkage and inaccuracies during flasking and deflasking [12]. While 3D printing allows rapid customization, limitations in printer resolution and post-processing shrinkage can impact its adaptation accuracy [13].

Patient satisfaction, which encompasses comfort, esthetics, and functionality, was significantly higher in the CAD/CAM group. This is reflective of the improved fit, surface smoothness, and reduced post-insertion adjustments often reported in digital workflows [14]. Clinical parameters such as retention and stability were also superior, which directly influence masticatory efficiency and overall patient confidence. Although 3D printed dentures were better accepted than conventional ones, their perceived fragility and limited shade options may have influenced user experience [15].

The findings of this study corroborate the growing body of evidence favoring digital denture workflows for their enhanced mechanical properties, clinical fit, and patient-centric outcomes. However, certain limitations must be acknowledged. The study sample was limited, and follow-up was short-term. Long-term clinical trials are necessary to validate the performance of 3D printed dentures in daily wear scenarios. Additionally, cost-effectiveness and accessibility of digital fabrication tools remain key considerations in low-resource settings.

This study demonstrated that the fabrication technique significantly influences the mechanical properties, dimensional accuracy, and clinical performance of complete dentures. CAD/CAM milled dentures exhibited the highest surface hardness, flexural strength, and adaptation accuracy, resulting in superior patient satisfaction and clinical fit. Conventional heat-cured dentures, while widely used, showed the lowest values in several parameters due to inherent processing limitations. 3D printed dentures offered promising results, particularly in surface hardness and adaptation, but require further improvement in mechanical strength. As digital dentistry continues to evolve, CAD/CAM and additive manufacturing technologies are expected to play a transformative role in prosthodontics. Clinicians should consider adopting these technologies where feasible to enhance patient outcomes and prosthetic longevity.

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