Fit Accuracy of Removable Partial Denture Frameworks Fabricated with CAD/CAM, Rapid Prototyping, and Conventional Techniques: A Systematic Review

Table 3

Methodological analysis and main outcome of the selected studies.

Authors	Groups		Sample size		Mean and STD in μm		Relevant features of study	Outcome
	Study	Control	Study	Control	Study	Control
Ye et al. [13]	CAD and SLM	LWT			Zone C: Zone M: Zone R:	Zone C: Zone M: Zone R:	Compared the difference in gap thickness between different zones of (Co-Cr) frameworks	Clinically acceptable fit with CAD and SLM techniques
Almufleh et al. [14]	Casting, CAD/CAM, and laser sintered	Laser sintered and casting; Casting only					The cobalt chromium alloy framework was compared in twelve participants. Dropout rate was 03 in this study	Patient satisfaction was high with CAD/CAM sintering laser techniques
Bajunaid et al. [15]	SLM technique	LWT			Short span 312.92; Long span 231.41	Short span 162.73; Long span 185.32	The measurements of the Co-Cr were determined at buccal, lingual, marginal, and central zones	The fit was accurate with SLM technique
Maryod et al. [16]	CAD/CAM	Conventional RPD			1. Retention: insertion visit .; 2. After 1 month .; 3. After 3 months	1. Retention: insertion visit; 2. After 1 month; 3. After 3 months	Digital force gauge was used for denture (Co-Cr) retention measurements up to 20 kg at different intervals	The retention (through retainer or clasp) of digitally fabricated dentures was higher than conventional dentures
Arnold et al. [17]	CAD/CAM and SLM	LWT			Indirect CAD/CAM horizontal arm; Vertical arm; Direct CAD/CAM horizontal arm; Vertical arm; Indirect RP horizontal arm; Vertical arm; Direct RP horizontal arm; Vertical arm	Mean LWT RPD horizontal clasp arm; Vertical clasp arm	Cobalt chromium frameworks were analyzed in laboratory with light microscope and stability testing	Improved fit with CAD/CAM technique. SLM framework had discrepancies
Soltanzadeh et al. [18]	CAD printing	LWT			Major; connector: Rest; Guiding plates; Reciprocal plates; Approaching arms	Major; connector; Rest; Guiding plates; Reciprocal plates; Approaching arms	Color mapping was used with metrology software. The gaps between denture framework and (trios 3) scanned models were analyzed at 8 points. The framework made of cobalt chromium alloy	The conventional RPD was accurate than 3D printed RPD.
Tregerman et al. [19]	Intra oral scanning SLM	Conventional impression, LWT and casting			The complete digital method was ratted better than analog and analog-digital methods ()	The complete digital method was ratted better than analog and analog-digital methods ()	The digital scan was carried out with TRIOS 3D shape.; The quality and fit of Co-Cr frameworks were rated by clinicians	The digital RPD platform process was superior to the traditional and analog-digital approaches
Chen et al. [20]	SLM	LWT			Kennedy 1: .; Kennedy 2: .; Kennedy 3: Kennedy 4:	Kennedy 1: .; Kennedy 2: .; Kennedy 3: Kennedy 4:	Cobalt chromium frameworks on 4 resin-based Kennedy’s arches were constructed	Regardless of the production method, a good fit was achieved between the frameworks, “connector, clasp” and the corresponding resin models
Honqqiang et al. [21]	PEEK and CAM/CAM	LWT					One-piece PEEK RPDs were formed by the CAD/CAM and LWT	The fit of CAD/CAM and RPD was superior

CLW: conventional lost wax technique; RPD: removable partial denture; CAD/CAM: computer-aided designing and computer-aided manufacturing; 3D: three dimensional; SLM: selective laser melting; LWT: lost wax technique; PEEK: polyetheretherketone; STD: standard deviation.