Abstract
Statement of problem
The development of polymethyl methacrylate (PMMA) computer-aided design and computer-aided
manufacturing (CAD-CAM) resin blocks with reported improved mechanical properties
has simplified complete denture production. However, whether the objective of improved
mechanical properties has been achieved compared with conventional heat-polymerized
PMMA is not yet clear.
Purpose
The purpose of this systematic review and meta-analysis was to evaluate the mechanical
properties of denture base resins manufactured by conventional heat-polymerization
and by CAD-CAM in terms of flexural strength, flexural modulus, and surface roughness.
Material and methods
Electronic databases (PubMed/MEDLINE, Scopus, Web of Science) were independently searched
by 2 researchers for relevant studies published up to November 2020. The population,
intervention, comparison, and outcome (PICO) question was, “Does the conventionally
manufactured, heat-polymerized PMMA resin, as a denture base, demonstrate the same
mechanical properties as the CAD-CAM resin block?” In addition, a meta-analysis was
based on the inverse variance method. Flexural strength, flexural modulus, and surface
roughness were analyzed through the continuous outcome evaluated by mean difference
and standard deviation, with 95% confidence intervals. To evaluated heterogeneity,
the I2 value (≤25%=low, ≥50%=moderate and ≥75%=high) and the P value were considered. P<.10 indicated statistical difference for heterogeneity. The effects of meta-analysis
were based on the results of heterogeneity as per the studies.
Results
Thirteen in vitro studies were included in the analysis. A total of 507 specimens
were evaluated, 222 conventional and 285 CAD-CAM. In terms of flexural strength, the
data showed no significant difference when conventional heat-polymerized PMMA was
compared with CAD-CAM PMMA resins (P=.06; mean difference=18.28; 95% confidence interval:-0.42 to 36.97). In terms of
flexural modulus, there was a significant difference for the CAD-CAM PMMA group (P=.01; mean difference=589.22; 95% confidence interval: 117.95 to 1060.48). In terms
of surface roughness, a significant difference was observed between the groups (P=.02; mean difference=-0.53; 95% confidence interval: -0.97 to -0.09) with the conventional
heat-polymerized PMMA resin having higher surface roughness values.
Conclusions
The mechanical properties of CAD-CAM PMMA resins were generally improved when compared
with heat-polymerized polymethyl methacrylate resin.
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References
- Prosthodontic treatment for edentulous patients.13th ed. Mosby/Elsevier, St. Louis2012: 133-140
- Phillips’ science of dental materials.12th ed. Saunders/Elsevier, Philadelphia2012: 94-483
- Complications with PMMA compared with other materials used in cranioplasty: a systematic review and meta-analysis.Braz Oral Res. 2018; 32: e31
- Mechanical properties of polyamide versus different PMMA denture base materials.J Prosthodont. 2012; 21: 173-176
- Current techniques in CAD-CAM denture fabrication.Gen Dent. 2016; 64: 23-28
- The effect of plasma on transverse strength, surface roughness and Candida adhesion of two types of acrylic denture base materials (Heat cure and light cure).J Bagh Coll Dentistry. 2012; 24: 10-17
- Adherence of Candida to complete denture surfaces in vitro: A comparison of conventional and CAD-CAM complete dentures.J Adv Prosthodont. 2017; 9: 402-408
- Evaluation of currently available CAD-CAM denture systems.Int J Prosthodont. 2017; 30: 116-122
- CAD-CAM fabricated complete dentures: Concepts and clinical methods of obtaining required morphological data.J Prosthet Dent. 2012; 107: 34-46
- Fabricating complete dentures with CAD-CAM technology.J Prosthet Dent. 2014; 111: 351-355
- Do CAD/CAM dentures really release less monomer than conventional dentures?.Clin Oral Investig. 2017; 21: 1697-1705
- Comparison of treatment outcomes in digital and conventional complete removable dental prosthesis fabrications in a predoctoral setting.J Prosthet Dent. 2015; 114: 818-825
- CAD-CAM produces dentures with improved fit.Clin Oral Investig. 2018; 22: 2829-2835
- A comparative study of the accuracy of five CAD-CAM systems.Med Pharm Rep. 2019; 92: 185-191
- Accuracy of digital complete dentures: A systematic review of in vitro studies.J Prosthet Dent. 2020; S0022-3913 (0): 30047
- A comparison of two digital techniques for the fabrication of complete removable dental prostheses: A pilot clinical study.J Prosthet Dent. 2016; 116: 756-763
- Standard No. 139 (ISO 20795-1), Denture base polymers.American Dental Association, 2013
- Flexural and fatigue strengths of denture base resin.J Prosthet Dent. 2008; 100: 47-51
- Flexural strength of acrylic resin denture bases processed by two different methods.J Dent Res Dent Clin Dent Prospects. 2014; 8: 148-152
- A Comparison of the flexural and impact strengths and flexural modulus of CAD-CAM and conventional heat-polymerized polymethyl methacrylate (PMMA).J Prosthodont. 2020; 29: 341-349
- Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement.Int J Surg. 2010; 8: 336-341
- Smoking and dental implants: a systematic review and meta-analysis.J Dent. 2015; 43: 487-498
- Prevalences of peri-implantitis and periimplant mucositis: systematic review and meta-analysis.J Dent. 2017; 62: 1-12
- A clinical comparison of 1-piece versus 2-piece implants: A systematic review and meta-analysis.J Prosthet Dent. 2020; 124: 439-445
- The residual monomer content and mechanical properties of CAD∖CAM resins used in the fabrication of complete dentures as compared to heat polymerized resins.Electron Physician. 2017; 9: 4766-4772
- Evaluation of flexural strength and surface properties of prepolymerized CAD-CAM PMMA-based polymers used for digital 3D complete dentures.Int J Comput Dent. 2018; 21: 31-40
- In vitro analysis of the fracture resistance of CAD-CAM denture base resins.Materials (Basel). 2018; 11: 401
- CAD/CAM milled complete removable dental prostheses: An in vitro evaluation of biocompatibility, mechanical properties, and surface roughness.Dent Mater J. 2018; 29: 526-533
- Effect of layering gingiva-shade composite resin on the strength of denture base polymers.J Prosthet Dent. 2019; 122: 153.e1-153.e8
- Mechanical properties of CAD/CAM denture base resins.Int J Prosthodont. 2019; 32: 104-106
- A comparison of the surface properties of CAD-CAM and conventional polymethylmethacrylate (PMMA).J Prosthodont. 2019; 28: 452-457
- Flexural strength of denture base acrylic resins processed by conventional and CAD-CAM methods.J Prosthet Dent. 2020; 123: 641-646
- Mechanical properties of a polymethyl methacrylate block for CAD/CAM dentures.J Oral Sci. 2020; 62: 420-422
- Assessment of CAD-CAM polymers for digitally fabricated complete dentures.J Prosthet Dent. 2021; 125: 175-181
- Comparison of mechanical properties of 3D-printed, CAD/CAM, and conventional denture base materials.J Prosthodont. 2020; 29: 524-528
- Physical properties of four acrylic denture base resins.J Contemp Dent Pract. 2005; 6: 93-100
- Effect of phosphate group addition on the properties of denture base resins.J Prosthet Dent. 2008; 100: 302-308
- Influence of anterior palatal coverage on perception and retention in complete dentures.J Prosthet Dent. 2011; 105: 272-279
- Managing complications resulting from limited prosthetic space with a monolithic, multichromatic CAD-CAM implant-retained overdenture: A dental technique.J Prosthet Dent. 2017; 118: 712-716
Article info
Publication history
Published online: May 21, 2021
Identification
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© 2021 by the Editorial Council for the Journal of Prosthetic Dentistry.
