Quantitative and Color‐Coded Assessment of Crown Preparation Using a 3D‐Printed Channel and Hole Guide: A Pilot Comparison With Conventional Guides

Yuwon Jeong; Rashdan Muteb J Alharbi; Sangmin Ham; Jae Hoon Lee; Jaehan Park; Hyeonjong Lee

doi:10.1002/jdd.70043

. 2025 Sep 8;90(6):776–784. doi: 10.1002/jdd.70043

Quantitative and Color‐Coded Assessment of Crown Preparation Using a 3D‐Printed Channel and Hole Guide: A Pilot Comparison With Conventional Guides

Yuwon Jeong ¹, Rashdan Muteb J Alharbi ², Sangmin Ham ², Jae Hoon Lee ², Jaehan Park ³, Hyeonjong Lee ^1,^✉

PMCID: PMC13280421 PMID: 40922101

ABSTRACT

Purpose

Crown preparation is a fundamental procedure in restorative dentistry. This study aimed to evaluate quantitative and color‐coded assessment of tooth reduction using various 3D‐printed tooth reduction guides in comparison to conventional guiding methods during crown preparation.

Methods

Twelve prosthodontic residents from a single prosthodontic graduate program (first year: n = 6; second year: n = 6) participated in this IRB‐approved study (Yonsei University Dental Hospital IRB 2‐2024‐0026). Recruitment was voluntary and the participation rate was 100%. Participants provided informed consent and performed tooth preparations using four guide types: freehand, putty guide, channel guide, and hole guide. Standardized reduction parameters were provided. Maxillary and mandibular models were generated using Medit Model Builder software, and selected teeth (upper left central incisor, lower left first molar, lower right second premolar) were converted into dies. Guides were designed with a uniform 2 mm thickness for stability. The putty guide was fabricated using polyvinylsiloxane, while channel and hole guides were 3D printed. Preparations were performed with a diamond bur, and completed teeth were scanned with an intraoral scanner. Accuracy was assessed by superimposing scans onto original tooth data using 3D inspection software, with under‐prepared areas analyzed in detail. Preparation times were recorded.

Results

The channel guide consistently demonstrated the highest accuracy, with the lowest mean distances in underprepared areas for all teeth. The freehand group showed the greatest variability and the highest mean distances in underprepared regions. Working time analysis showed significant differences among groups; the putty group required the longest time, while the freehand group was the most time‐efficient. The channel group demonstrated moderate working times with low variability.

Conclusions

The novel channel‐type guide showed potential for improving preparation accuracy. However, underprepared areas in critical regions could compromise restoration durability. While the guides had minimal impact on procedure time, further studies are needed to confirm these findings in a wider clinical context.

Keywords: dental education, digital dentistry, digital feedback, operative dentistry, time efficiency, tooth preparation

1. Introduction

Tooth reduction for full‐coverage crown is one of the most commonly performed procedures in routine dental practice. Achieving an adequate tooth preparation design is critical, as it directly influences the mechanical performance, longevity, and overall success of the final restoration [1, 2, 3, 4, 5, 6, 7, 8]. Given the importance of these principles, it is essential that dental students receive thorough and systematic training in tooth preparation techniques during their education.

Traditionally, the training of dental students in tooth preparation has relied on self‐assessment, which is subsequently confirmed and evaluated by a supervising professor [9, 10, 11]. For untrained dental students, assessing and achieving proper tooth preparation design can be particularly challenging. It is well‐documented that many students struggle to meet the required standards for adequate preparation, often resulting in over‐ or under‐preparation of tooth structure [12, 13, 14, 15].

To aid in the training process, tooth preparation guiding techniques have been employed to assist students in achieving more accurate and consistent results. Traditionally, these guides have been fabricated using silicone materials or thermoplastic sheets [16, 17, 18]. The fabrication process involves taking an impression of the teeth prior to preparation, allowing the clearance for the restoration to be visually evaluated and quantified. However, visual assessment methods are inherently subjective and lack precision.

The integration of digital worfklows into dental education has introduced a more efficient and precise approach to training preclinical dental students [19, 20, 21, 22]. Additive manufacturing, commonly referred to as three‐dimensional (3D) printing, has been employed to create more realistic practice models, enhancing the teaching and training experience for dental students [21, 23, 24, 25, 26, 27].

Recently, additively manufactured tooth preparation guides have been developed as innovative tools to facilitate precise and controlled tooth preparation. These guides have demonstrated their utility in achieving optimal outcomes with minimal and conservative tooth reduction [28, 29].

However, the use of hole guide presents several limitations such as the restricted visual access, which can result in a “blind” preparation process that relies entirely on the guide for accuracy. In addition, the water spray from the handpiece, when directed through the same hole used for preparation, can further obscure visibility due to the accumulation of water and debris. CAD/CAM technology enables the creation of precise and customizable guides allowing for greater design flexibility and improved accuracy.

In this study, a channel design was incorporated into the preparation guides to overcome the visual obstructions inherent in hole‐guided techniques, thereby enhancing visualization during tooth preparation. In addition, it allows for the efficient release of water from the handpiece, minimizing interference caused by water accumulation and pressure within the guide.

The primary objective of this study was to assess the accuracy achieved by dental students using various 3D‐printed tooth‐preparation guides and to compare it with that obtained using a conventional guide and freehand preparation. The secondary objective was to evaluate the working time of each preparation guide. The null hypothesis posted that there would be no significant differences in the accuracy of tooth preparation achieved using 3D‐printed guides compared to conventional preparation methods.

2. Materials and Methods

2.1. Study Approval and Participants

Twelve prosthodontic residents from a single prosthodontic graduate program (first year: n = 6; second year: n = 6) participated in this IRB‐approved study by Yonsei University Dental Hospital, Institutional Review Board (IRB, 2‐2024‐0026). Recruitment was voluntary and the participation rate was 100%. Prior to participation, all residents provided written informed consent after receiving comprehensive information regarding the study's objectives and procedure. The tooth preparation guides were divided into control group (Freehand), putty guide, channel guide, and hole guide. Participants were provided with a standardized guidelines detailing the parameters for tooth reduction.

2.2. Study Design

The overall study workflow is described in Figure 1. Maxillary and mandibular models were generated using the Medit Model Builder software (Medit Link, Medit, South Korea). Upper‐left central incisor, lower‐left first molar, and lower‐right second premolar, were selected and converted into dies for further analysis. The models were exported as stereolithography (STL) files and imported into a 3D modeling software (Meshmixer, Autodesk, USA), where they were adapted to fit within a simulated phantom head. Using the same software, channel‐ and hole‐type preparation guides were designed with a uniform thickness of 2mm and extended to cover half of adjacent tooth, thereby improving stability and positional accuracy during use. Both the internal channel width and hole diameter were set to 1 mm (Figure 2).

Study workflow and guide types. From left to right: (1) Participant cohort—12 prosthodontic residents (PGY‐1, n = 6; PGY‐2, n = 6). (2) Tooth‐preparation phase—each resident prepared three tooth types (central incisor, premolar, molar) with four strategies: channel guide, hole guide, putty guide, and freehand. This yielded 12 preparations per participant and 144 preparations overall. (3) Comprehensive analysis—outcomes included sectional reduction accuracy on three orthogonal planes, quantification of under‐prepared area (< 0.5 mm) with a color‐coded surface‐deviation map, and total preparation time. Lower images illustrate the four preparation strategies: channel guide (with 1 mm depth channels), hole guide, putty guide, and freehand group.

Digital preparation workflow. (A) 3D design of channel and hole guides for precise preparation. (B) Tooth preparation method using 3D printed guides.

The putty guide was fabricated by taking an impression using polyvinylsiloxane material (Express STD, 3M, USA). The impression was subsequently sectioned longitudinally along the bucco‐lingual (B‐L) plane to expose half of the tooth. This modification allowed for direct visual assessment of the tooth during the preparation process. The initial preparation for the channel and hole preparation guides was performed using a 3.1 mm working length standard diamond bur (EX‐41, Mani, Japan). The bur was inserted through the 2 mm‐thick guide, leaving 1 mm of the bur exposed to achieve a 1 mm reduction of the incisal/occlusal and buccal/lingual surfaces. After completing the depth indentation, a chamfer bur, occlusal reduction bur, interproximal bur (TR11, TR13, EX‐20, Mani, Japan) were used to prepare the remaining tooth structure. All participants were instructed to remove additional tooth structure to achiever a total reduction of 1.5 mm at the functional cusps of premolars and molars, and 2 mm at the incisal edge of central incisors. A chamfer finishing line was specified for all surfaces.

2.3. Standardization of Procedures

Before data collection, all participants completed an investigator‐supervised calibration covering the preparation protocol and evaluation criteria. Thereafter, all preparations were performed under standardized conditions: identical written and verbal instructions, the same dental unit and handpiece settings, the same bur set and irrigation, and a fixed time allowance; no formative feedback was provided.

2.4. 3D Evaluation

Upon completion of the tooth preparation, each tooth was scanned using an intraoral scanner (i700, Medit, South Korea). The scanned data of each prepared tooth were superimposed onto the original tooth data to assess the accuracy of the preparation. The accuracy of the tooth preparation, as influenced by the preparation guides, was evaluated using a 3D inspection software (GOM Inspect, ZEISS, Germany).

The analysis comprised three distinct evaluations: (1) amount of tooth reduction, (2) identification of under‐prepared regions, referred to as area of interest (AOI), and (3) measurement of preparation time for each guide.

The amount of tooth reduction was assessed by positioning specific reference points on the surface of the unprepared tooth (reference tooth). The distance between the reference tooth and the prepared tooth was measured for each surface. For central incisor, two surfaces were analyzed: B‐L, and inciso‐cervical (I‐C). For premolar and molar, three surfaces were analyzed: B‐L, mesio‐distal (M‐D), and occluso‐cervical (O‐C) (Figure 3). All reference points were placed 2 mm coronal to the gingival margin to maintain consistency. Because the finishing line was uniformly prepared as a chamfer—independent of the type of preparation guide—this fixed distance ensured that every measurement originated from an equivalent anatomical landmark.

Measurement of distances between corresponding points on unprepared tooth and prepared tooth to evaluate amount of tooth reduction of central incisor, premolar, and molar.

The AOI was defined as the underprepared region, encompassing the tooth surface with a reduction of less than 0.5 mm. Within this AOI, the distance between the reference tooth and the prepared tooth was calculated (Figure 4). In addition, the preparation time for each group was measured using a stopwatch and recorded in seconds, starting from the beginning of the preparation until the point where the participant subjectively perceived that approximately 90% of the tooth preparation was completed, leaving only the final finishing step. This approach ensured a comparison that was more specific to the guide.

Evaluation of the area of interest (AOI), defined as the combined red and yellow regions indicating under‐prepared surfaces where tooth reduction was < 0.5 mm. Red denotes surfaces reduced by < 0.2 mm, and yellow denotes surfaces reduced by 0.2–0.5 mm. The figure presents a representative result from a single participant.

2.5. Statistical Analysis

All statistical analyses were performed using IBM SPSS Statistics 27 (IBM Corp., Armonk, NY, USA). The normality of data distribution was assessed using the Shapiro–Wilk test. If the data followed a normal distribution, a one‐way analysis of variance (ANOVA) was conducted to compare the means among the four preparation strategies (Channel Guide, Hole Guide, Putty, and Free Hand). For multiple comparisons, Tukey's Honestly Significant Difference (HSD) post‐hoc test was applied to identify significant differences between groups. A p value of less than 0.05 was considered statistically significant for all analyses.

3. Results

Overall results of the amount of reduction of prepared teeth across the preparation methods are shown in Table 1. For the central incisor, the results showed that the channel guide consistently achieved the highest amount of tooth reduction across most surfaces, particularly on the buccal and incisal areas. The hole guide and putty methods showed intermediate reductions with comparable results, while the freehand method generally resulted in the least reduction, especially on lingual surfaces. Variability was more pronounced on the incisal and lingual surfaces across all methods.

TABLE 1.

Mean and standard deviation of the amount of reduction in three sections of the maxillary central incisor, mandibular premolar, and mandibular molar for different preparation strategies.

		Channel guide	Hole guide	Putty	Freehand
Incisor	B‐L: Labial	1.55 ± 0.37^a	1.31 ± 0.41^b	1.20 ± 0.26^b	1.22 ± 0.28^b
	B‐L: Incisal	2.37 ± 0.75^a	1.91 ± 0.77^b	2.05 ± 0.50^ab	1.84 ± 0.56^b
	B‐L: Lingual fossa	0.94 ± 0.38^a	0.84 ± 0.36^ab	0.79 ± 0.31^ab	0.65 ± 0.29^b
	B‐L: Lingual cingulum	1.39 ± 0.37^a	1.39 ± 0.37^a	1.30 ± 0.37^a	1.25 ± 0.25^a
	B‐L: Lingual	0.81 ± 0.55^a	0.85 ± 0.61^a	0.83 ± 0.57^a	0.73 ± 0.52^a
	B‐L: Overall	1.46 ± 0.72	1.29 ± 0.64	1.17 ± 0.56	1.26 ± 0.59
	I‐C: Labial	1.28 ± 0.25^a	1.18 ± 0.28^ab	1.17 ± 0.22^b	1.16 ± 0.24^b
	I‐C: Mesial	0.33 ± 0.30^a	0.34 ± 0.30^a	0.37 ± 0.31^a	0.35 ± 0.32^a
	I‐C: Lingual	0.24 ± 0.28^ab	0.31 ± 0.33^a	0.30 ± 0.32^ab	0.17 ± 0.17^b
	I‐C: Distal	0.40 ± 0.28^a	0.46 ± 0.30^a	0.46 ± 0.30^a	0.48 ± 0.28^a
	I‐C: Overall	0.59 ± 0.52	0.59 ± 0.47	0.55 ± 0.47	0.59 ± 0.46

	Premolar				Molar
	Channel guide	Hole guide	Putty	Freehand	Channel guide	Hole guide	Putty	Freehand
B‐L: Buccal	1.05 ± 0.73^a	1.01 ± 0.72^a	0.99 ± 0.67^a	1.03 ± 0.78^a	1.34 ± 0.29^ab	1.47 ± 0.27^a	1.23 ± 0.24^b	1.38 ± 0.36^a
B‐L: Buccal cusp	1.53 ± 0.95^a	1.43 ± 0.91^a	1.47 ± 0.96^a	1.51 ± 0.96^a	1.60 ± 0.33^a	1.89 ± 0.46^b	1.54 ± 0.38^a	1.64 ± 0.47^ab
B‐L: Fossa	0.82 ± 0.52^a	0.72 ± 0.39^a	0.79 ± 0.46^a	0.78 ± 0.51^a	0.84 ± 0.50^a	1.05 ± 0.55^a	0.86 ± 0.45^a	0.86 ± 0.50^a
B‐L: Lingual cusp	1.19 ± 0.70^a	1.04 ± 0.62^a	1.01 ± 0.65^a	1.04 ± 0.73^a	1.85 ± 0.42^ab	2.06 ± 0.50^a	1.69 ± 0.32^b	1.73 ± 0.40^b
B‐L: Lingual	0.98 ± 0.50^a	0.98 ± 0.51^a	0.92 ± 0.49^a	0.94 ± 0.61^a	1.31 ± 0.41^ab	1.50 ± 0.46^a	1.15 ± 0.31^b	1.27 ± 0.26^b
B‐L: Overall	1.10 ± 0.72	1.03 ± 0.68	1.05 ± 0.76	1.02 ± 0.69	1.21 ± 0.64	1.24 ± 0.66	1.21 ± 0.64	1.20 ± 0.64
M‐D: Mesial	1.21 ± 0.40^a	1.10 ± 0.40^a	1.14 ± 0.46^a	1.22 ± 0.37^a	1.36 ± 0.33^a	1.40 ± 0.31^a	1.43 ± 0.25^a	1.44 ± 0.31^a
M‐D: Mesial MR	1.62 ± 0.44^a	1.41 ± 0.46^a	1.58 ± 0.52^a	1.64 ± 0.40^a	1.90 ± 0.46^a	2.01 ± 0.40^a	1.89 ± 0.39^a	1.85 ± 0.41^a
M‐D: Fossa	1.02 ± 0.41^a	0.84 ± 0.41^a	0.98 ± 0.48^a	0.99 ± 0.45^a	0.79 ± 0.50^a	0.93 ± 0.56^a	0.85 ± 0.46^a	0.79 ± 0.48^a
M‐D: Distal MR	1.85 ± 0.38^a	1.60 ± 0.39^b	1.78 ± 0.45^ab	1.91 ± 0.37^a	1.65 ± 0.46^a	1.76 ± 0.49^a	1.63 ± 0.41^a	1.77 ± 0.43^a
M‐D: Distal	1.18 ± 0.44^a	1.08 ± 0.43^a	1.12 ± 0.45^a	1.19 ± 0.44^a	1.37 ± 0.34^a	1.36 ± 0.39^a	1.38 ± 0.35^a	1.50 ± 0.37^a
M‐D: Overall	1.32 ± 0.51	1.16 ± 0.49	1.33 ± 0.52	1.27 ± 0.55	1.31 ± 0.60	1.40 ± 0.61	1.36 ± 0.59	1.34 ± 0.55
O‐C: Buccal	1.09 ± 0.24^ac	0.94 ± 0.31^b	0.99 ± 0.30^ab	1.12 ± 0.34^c	1.18 ± 0.22^ab	1.26 ± 0.25^a	1.13 ± 0.24^b	1.27 ± 0.29^a
O‐C: Mesial	0.73 ± 0.27^a	0.62 ± 0.28^a	0.65 ± 0.29^a	0.73 ± 0.22^a	1.06 ± 0.28^a	1.10 ± 0.23^a	1.13 ± 0.20^a	1.15 ± 0.21^a
O‐C: Lingual	1.01 ± 0.23^a	1.01 ± 0.21^a	0.97 ± 0.25^a	1.01 ± 0.38^a	1.28 ± 0.33^ab	1.39 ± 0.27^a	1.17 ± 0.25^b	1.31 ± 0.22^a
O‐C: Distal	0.73 ± 0.26^a	0.68 ± 0.29^a	0.69 ± 0.32^a	0.78 ± 0.30^a	1.04 ± 0.19^a	1.03 ± 0.24^a	1.03 ± 0.29^a	1.16 ± 0.26^a
O‐C: Overall	0.92 ± 0.29	0.84 ± 0.32	0.94 ± 0.36	0.85 ± 0.33	1.16 ± 0.28	1.23 ± 0.29	1.24 ± 0.26	1.12 ± 0.25

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Note: Superscript letters indicate statistical comparisons within each row. Identical letters denote no statistically significant differences among the preparation strategies (p > 0.05). unit: mm/B‐L: Bucco‐Lingual, M‐D: Mesio‐Distal, I‐C: Inciso‐Cervical, O‐C: Occluso‐Cervical, MR: marginal ridge.

For the premolar, the channel guide generally achieved the highest reduction in most areas, such as the buccal cusp, mesial marginal ridge (MR), and distal MR. the hole guide showed slightly lower reductions, particularly on the occlusal and distal MR surfaces. The putty method demonstrated intermediate reductions, with values close to the hole guide, such as on the lingual cusp and occlusal surfaces. The freehand method showed comparable reductions to the channel guide in some areas, such as the buccal cusp and distal MR, but was less consistent, particularly on the occlusal and lingual surfaces.

For the molar. the hole guide generally achieved the highest reduction in most areas, such as the buccal cusp, lingual cusp, and mesial MR, indicating its superior reduction capability. The channel guide showed slightly lower reductions but remained consistent, with notable values on the lingual cusp and mesial MR. The putty method demonstrated intermediate reductions, such as on the buccal cusp and lingual cusp, but generally resulted in lower values compared to the guided techniques. The freehand method showed comparable reductions to the channel guide in some areas, such as the buccal cusp and distal MR, but was less consistent, particularly on the occlusal surface.

Variability was higher for cusp and MR areas across all methods for the premolar and molar, indicating greater inconsistency in these regions. Overall, guided techniques (channel and hole guides) showed more consistent results compared to the putty and freehand methods.

The overall results of the AOI are shown in Table 2. The channel guide consistently demonstrated the smallest values. the hole guide showed slightly larger results, particularly for central incisors and premolars, but remained more consistent than the putty and freehand methods. The putty method resulted in larger values across all teeth. The freehand method exhibited the largest values for central incisors and molars, with high variability. Overall, the channel guide demonstrated the most consistent performance, while the freehand method showed the least.

TABLE 2.

Mean and standard deviation of the underprepared area (> 0.5 mm) and preparation time for each tooth.

		Channel guide	Hole guide	Putty	Freehand
Underprepared area (mm)	Central incisor	2.12 ± 5.24^a	3.49 ± 5.74^a	4.07 ± 6.52^a	4.96 ± 5.48^a
	Premolar	0.50 ± 1.44^a	1.52 ± 2.92^a	1.36 ± 2.61^a	1.00 ± 2.12^a
	Molar	6.74 ± 6.85^a	5.77 ± 5.59^a	6.34 ± 6.70^a	6.95 ± 5.27^a
	Overall	3.12 ± 3.24	3.59 ± 2.13	3.92 ± 2.49	4.30 ± 3.03
Preparation time (s)	Central incisor	459 ± 243	463 ± 231	559 ± 487	429 ± 188
	Premolar	432 ± 210	472 ± 181	462 ± 242	479 ± 262
	Molar	448 ± 258	406 ± 22	490 ± 237	419 ± 202

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Note: Superscript letters indicate statistical comparisons within each row of the underprepared area analysis. Identical letters indicate no statistically significant differences among the preparation strategies (p > 0.05). There were no statistically significant differences among groups in the preparation time analysis.

For the results of working time across the preparation methods, the channel guide and hole guide exhibited similar working times (Table 2). The putty method required the longest working times, particularly for central incisors and molars. The freehand method showed the fastest working time for central incisors but was less consistent for premolars and molars. Overall, the channel and hole guides provided consistent working times, while the putty method required the most time, and the freehand method showed variability depending on the tooth.

4. Discussion

In this study, 12 participants performed tooth preparations on central incisors, premolars, and molars using four different preparation strategies. Each participant prepared 12 teeth, resulting in a total of 144 prepared teeth, which were comprehensively analyzed across the groups. With advancements in digital dentistry, various CAD‐designed, 3D‐printed preparation guides have been introduced [24, 30, 31]. In this study, a novel channel‐type preparation guide was proposed. Compared to the hole‐type guide, the channel guide has a simpler design and does not obstruct access to water spray, ensuring adequate cooling during tooth reduction and minimizing the risk of overheating.

The preparation guides were designed to achieve a baseline reduction of 1 mm, with an additional 1 mm reduction instructed for the incisal edge and 0.5 mm reduction for functional cusp. The effectiveness of each guide type was evaluated in Table 1, particularly in the B‐L section analysis. Due to the guide's structural design, indentation was primarily formed in the buccal (labial), occlusal (incisal), and lingual regions. However, no statistically significant differences were observed among the four groups in the B‐L section measurements. Since the participants were prosthodontic residents with teeth preparation experience, it would be possible that a greater difference would be observed if the study were conducted with less experienced dental students.

Regarding the M‐D, I‐C, or O‐C sections, the preparation guide does not appear to have a significant effect, as it was designed specifically for the buccal, occlusal, and lingual surfaces. However, it provides an overall and detailed assessment of the preparation amount across various areas. In the I‐C section of incisor teeth, the lingual area tended to show insufficient preparation, particularly in the freehand group.

Similarly, tooth preparation time showed no statistically significant differences among the groups, though individual variations were substantial, resulting in high standard deviation values. These findings suggest that preparation guides do not significantly impact clinical preparation time, either by reducing or prolonging the procedure in this study.

There are studies which provide color coded and sectional analysis reports [32, 33]. However, a unique aspect of this study is the use of a color‐coded surface‐deviation map to isolate and quantify under‐prepared areas smaller than 0.5 mm—an analytic approach not previously reported in crown‐preparation research.

The map pinpointed consistent deficits in the lingual fossa of maxillary central incisors and in the occlusal fossae of premolars and molars (Table 2, Figure 4). By displaying the exact location and surface area of insufficient reduction, the tool offers powerful educational benefits: students receive high‐resolution feedback, can visualize how their preparation translates into 3D form, and can compare their results quantitatively against preset tolerance bands. Instructors, in turn, can tailor remediation to specific high‐risk zones and track longitudinal improvement. Because the threshold can be adjusted, the system is adaptable to different restorative materials and learning objectives, enhancing both formative assessment and self‐directed skill acquisition in pre‐clinical and clinical settings. Faculty can also use these data to create objective rubrics or OSCE checklists that focus on high risk areas—such as the lingual fossa of incisors and the occlusal fossae of posterior teeth—thereby replacing subjective critique with targeted coaching.

Among the four groups, the freehand group tended to show less favorable results, whereas the channel guide demonstrated the best overall trend in the central incisor and premolar. In the case of the central incisor, underprepared areas were predominantly observed in the lingual fossa, while for premolars and molars, they were mainly found in the occlusal fossa. This finding suggests that, in routine clinical practice, these areas may not always receive sufficient reduction. Therefore, special attention should be given to ensure sufficient tooth reduction in these regions to achieve optimal clinical outcomes.

This study offers several methodological strengths. First, 14 standardized reference points across three planes provided a high‐resolution, 3D profile of reduction accuracy. Second, a color coded surface deviation map objectively quantified under‐prepared areas smaller than 0.5 mm in mm²—an analytic detail not reported previously. Third, to our knowledge, this is the first controlled comparison of a channel type 3D printed guide with hole, putty, and free‐hand techniques, establishing baseline data for future innovations.

Considering the overall results, the null hypothesis was partially rejected: although a few measurement points showed statistically significant differences (Table 1), most points did not, and the observed differences are unlikely to be clinically meaningful. The 3D‐printed guide also showed no significant advantage over the other groups in total under‐prepared area (Table 2). Nevertheless, we anticipate that its benefits will become more pronounced as 3D‐printer resolution improves. In addition, incorporating appropriate internal relief to enhance seating accuracy should further increase the guide's clinical utility and educational value for dental students.

This study has certain limitations. First, the sample size was relatively small, consisting of only 12 participants, which may limit the generalizability of the findings. In addition, all participants were prosthodontic residents from a single graduate program (six first‐year and six second‐year residents). As such, the findings may not be directly generalizable to predoctoral dental education settings or to practitioners with substantially different experience levels. Future studies including dental students or clinicians from diverse training backgrounds would help to determine the broader applicability of these results. Second, some error may have arisen from the fit of the 3D‐printed preparation guide. Because the guide is fabricated from a rigid material, incomplete adaptation to the tooth surface is possible and could contribute to under‐prepared areas. Although participants were instructed to verify and adjust the guide before use, this source of error cannot be entirely ruled out. The variability in outcomes may also be influenced by differences in the participants’ clinical skills, which cannot be entirely eliminated despite standardization efforts. Third, the study primarily focused on accuracy and preparation time, but other clinical factors such as operator fatigue, ease of use, and patient comfort were not evaluated. Future studies should include a larger, more diverse participant pool and explore additional clinical parameters to further validate the efficacy of CAD‐designed, 3D‐printed preparation guides. Before recommending adoption in indirect restorative dental education, applicability should be validated in prospective cohorts of predoctoral students. When software emerges that can automatically create guides with surface‐specific depth cuts, routine clinical adoption of 3D‐printed preparation guides will likely follow.

5. Conclusion

In this pilot study, none of the four preparation methods—free‐hand, putty guide, hole‐type guide, or channel‐type guide—showed a statistically significant advantage in reduction accuracy, under‐prepared area, or preparation time. The channel‐type guide displayed a non‐significant trend toward smaller under‐prepared areas on central incisors and premolars. Larger, powered studies are needed to determine whether such differences are clinically relevant.

Author Contributions

Yuwon Jeong: manuscript, in charge of the study. Rashidan Muteb: performing the study, analysis. Sangmin Ham: measurement, manuscript. Jae Hoon Lee: analysis, advice. Jaehan Park: performing study and advising. Hyeonjong Lee: statistics, manuscript, and comments as the corresponding author.

Conflicts of Interest

The authors declare no conflicts of interest.

Acknowledgments

This study was supported by the Yonsei University College of Dentistry Fund (6‐2022‐0007).

Jeong Y., Alharbi R. M. J., Ham S., Lee J. H., Park J., and Lee H., “Quantitative and Color‐Coded Assessment of Crown Preparation Using a 3D‐Printed Channel and Hole Guide: A Pilot Comparison With Conventional Guides.” Journal of Dental Education 90, no. 6 (2026): 776–784. 10.1002/jdd.70043

Funding: This study was supported by the Yonsei University College of Dentistry Fund (6‐2022‐0007).

References

1. Podhorsky A., Rehmann P., and Wöstmann B., “Tooth Preparation for Full‐Coverage Restorations—A Literature Review,” Clinical Oral Investigations 19, no. 5 (2015): 959–968. [DOI] [PubMed] [Google Scholar]
2. Falahchai M., Babaee Hemmati Y., Neshandar Asli H., and Rezaei E., “Effect of Tooth Preparation Design on Fracture Resistance of Zirconia‐Reinforced Lithium Silicate Overlays,” Journal of Prosthodontics 29, no. 7 (2020): 617–622. [DOI] [PubMed] [Google Scholar]
3. Nasir M. Q. and Kadhim A. J., “Marginal Adaptation of Different Monolithic Zirconia Crowns With Horizontal and Vertical Finish Lines: A Comparative In Vitro Study,” Journal of Dental Research, Dental Clinics, Dental Prospects 17, no. 4 (2023): 235–241. [DOI] [PMC free article] [PubMed] [Google Scholar]
4. Ashour A. M., El‐Kateb M. M., and Azer A. S., “The Effect of Two Preparation Designs on the Fracture Resistance and Marginal Adaptation of Two Types of Ceramic Crowns Using CAD/CAM Technology (In Vitro Study),” BMC Oral Health 24 (2024): 1065. [DOI] [PMC free article] [PubMed] [Google Scholar]
5. Findakly M. B. and Jasim H. H., “Influence of Preparation Design on Fracture Resistance of Different Monolithic Zirconia Crowns: A Comparative Study,” Journal of Advanced Prosthodontics 11 (2019): 324. [DOI] [PMC free article] [PubMed] [Google Scholar]
6. Luo B., Sun X., He L., Zhao L., Liu X., and Jiang Q., “Impact of Different Axial Wall Designs on the Fracture Strength and Stress Distribution of Ceramic Restorations in Mandibular First Molar,” BMC Oral Health 22 (2022): 549. [DOI] [PMC free article] [PubMed] [Google Scholar]
7. Motta A. B., Pereira L. C., Duda F. P., and Anusavice K. J., “Influence of Substructure Design and Occlusal Reduction on the Stress Distribution in Metal Ceramic Complete Crowns: 3D Finite Element Analysis,” Journal of Prosthodontics 23 (2014): 381–389. [DOI] [PubMed] [Google Scholar]
8. Zidan O. and Ferguson G. C., “The Retention of Complete Crowns Prepared With Three Different Tapers and Luted With Four Different Cements,” Journal of Prosthetic Dentistry 89 (2003): 565–571. [DOI] [PubMed] [Google Scholar]
9. Rashid N., Talib M., Ali W., Jaafar A., and Alaudding M., “An Evaluation of Full Coverage Crown Preparation: An Institutional Analysis,” Journal of Clinical and Diagnostic Research 14 (2020): 35–39. [Google Scholar]
10. Silvestri F., Odisho N., Kumar A., and Grigoriadis A., “Examining Gaze Behavior in Undergraduate Students and Educators During the Evaluation of Tooth Preparation: An Eye‐Tracking Study,” BMC Medical Education 24, no. 1 (2024): 1030. [DOI] [PMC free article] [PubMed] [Google Scholar]
11. Okuyama Y., Kasahara S., and Kimura K., “Quantitative Evaluation of Axial Wall Taper in Prepared Artificial Teeth,” Journal of Oral Science 47, no. 3 (2005): 129–133. [DOI] [PubMed] [Google Scholar]
12. Noonan J. E. Jr and Goldfogel M. H., “Convergence of the Axial Walls of Full Veneer Crown Preparations in a Dental School Environment,” Journal of Prosthetic Dentistry 66, no. 5 (1991): 706–708. [DOI] [PubMed] [Google Scholar]
13. Yoon S. S., Cheong C., Preisser J., Jun S., Chang B. M., and Wright R. F., “Measurement of Total Occlusal Convergence of 3 Different Tooth Preparations in 4 Different Planes by Dental Students,” Journal of Prosthetic Dentistry 112, no. 2 (2014): 285–292. [DOI] [PubMed] [Google Scholar]
14. Strain K. J., Mackie J., Bonsor S. J., and Macfarlane T. V., “Crown Taper Angles Achieved by Dental Students: A Systematic Review,” Journal of Dental Education 82, no. 11 (2018): 1203–1212. [DOI] [PubMed] [Google Scholar]
15. Al‐Omari W. M. and Al‐Wahadni A. M., “Convergence Angle, Occlusal Reduction, and Finish Line Depth of Full‐Crown Preparations Made by Dental Students,” Quintessence International 35, no. 4 (2004): 287–293. [PubMed] [Google Scholar]
16. Moskowitz M. E., Loft G. H., and Reynolds J. M., “Using Irreversible Hydrocolloid to Evaluate Preparations and Fabricate Temporary Immediate Provisional Restorations,” Journal of Prosthetic Dentistry 51, no. 3 (1984): 330–333. [DOI] [PubMed] [Google Scholar]
17. Gardner L. K., Rahn A. O., Parr G. R., and Richardson D. W., “Using a Tooth‐Reduction Guide for Modifying Natural Teeth,” Journal of Prosthetic Dentistry 63, no. 6 (1990): 637–639. [DOI] [PubMed] [Google Scholar]
18. Oh W.‐S., Saglik B., and May K B., “Tooth Reduction Guide Using Silicone Registration Material Along With Vacuum‐Formed Thermoplastic Matrix,” Journal of Prosthodontics 19, no. 1 (2010): 81–83. [DOI] [PubMed] [Google Scholar]
19. Stoilov M., Trebess L., Klemmer M., Stark H., Enkling N., and Kraus D., “Comparison of Digital Self‐Assessment Systems and Faculty Feedback for Tooth Preparation in a Preclinical Simulation,” International Journal of Environmental Research and Public Health 18, no. 24 (2021): 13218. [DOI] [PMC free article] [PubMed] [Google Scholar]
20. Dobroś K., Hajto‐Bryk J., and Zarzecka J., “Application of 3D‐Printed Teeth Models in Teaching Dentistry Students: A Scoping Review,” European Journal of Dental Education 27, no. 1 (2023): 126–134. [DOI] [PubMed] [Google Scholar]
21. Del Hougne M., Behr G., Schmitter M., and Höhne C., “3D Printed Teeth With Adhesive Bridge Preparation Guide,” Scientific Reports 14, no. 1 (2024): 22017. [DOI] [PMC free article] [PubMed] [Google Scholar]
22. Chaudhari P. K., Dhillon H., Dhingra K., and Alam M. K., “3D Printing for Fostering Better Dental Education,” Evidence‐Based Dentistry 22, no. 4 (2021): 154–155. [DOI] [PubMed] [Google Scholar]
23. Höhne C., Dickhaut N., and Schmitter M., “Introduction of a New Teaching Concept for Dentin Post Preparation With 3D Printed Teeth,” European Journal of Dental Education 24, no. 3 (2020): 499–506. [DOI] [PubMed] [Google Scholar]
24. Höhne C., Rammler T., and Schmitter M., “3D Printed Teeth With Included Veneer Preparation Guide,” Journal of Prosthodontics 30, no. 1 (2021): 51–56. [DOI] [PubMed] [Google Scholar]
25. Kim Y.‐K., Kim J.‐H., Jeong Y., Yun M.‐J., and Lee H., “Comparison of Digital and Conventional Assessment Methods for a Single Tooth Preparation and Educational Satisfaction,” European Journal of Dental Education 27, no. 2 (2023): 262–270. [DOI] [PubMed] [Google Scholar]
26. Chen J., Luo Y., Li H., et al., “Evaluating the Effectiveness of a Novel Digital Evaluation Technology on Dental Preclinical Crown Preparation Training,” Journal of Dental Education 88, no. 7 (2024): 983–993. [DOI] [PubMed] [Google Scholar]
27. Mahrous A., Elgreatly A., Qian F., and Schneider G. B., “A Comparison of Pre‐Clinical Instructional Technologies: Natural Teeth, 3D Models, 3D Printing, and Augmented Reality,” Journal of Dental Education 85, no. 11 (2021): 1795–1801. [DOI] [PubMed] [Google Scholar]
28. Robles M., Jurado C. A., Azpiazu‐Flores F. X., Villalobos‐Tinoco J., Afrashtehfar K. I., and Fischer N. G., “An Innovative 3D Printed Tooth Reduction Guide for Precise Dental Ceramic Veneers,” Journal of Functional Biomaterials 14, no. 4 (2023): 216. [DOI] [PMC free article] [PubMed] [Google Scholar]
29. Sartori N., Ghishan T., O'neill E., Hosney S., and Zoidis P., “Digitally Designed and Additively Manufactured Tooth Reduction Guides for Porcelain Laminate Veneer Preparations: A Clinical Report,” Journal of Prosthetic Dentistry 131, no. 5 (2024): 768–773. [DOI] [PubMed] [Google Scholar]
30. Da Silva B. P., Stanley K., and Gardee J., “Laminate Veneers: Preplanning and Treatment Using Digital Guided Tooth Preparation,” Journal of Esthetic and Restorative Dentistry 32, no. 2 (2020): 150–160. [DOI] [PubMed] [Google Scholar]
31. Puri N., Atria P. J., Oquendo A., Blatz M. B., and Sampaio C. S., “A Fully Digital Workflow Involving 3D Printed Tooth Reduction Guides and Injection Resin‐Indexes to Restore an Impacted Canine,” Journal of Esthetic and Restorative Dentistry 36, no. 10 (2024): 1388–1395. [DOI] [PubMed] [Google Scholar]
32. Chen J., Luo Y., Li H., et al., “Evaluating the Effectiveness of a Novel Digital Evaluation Technology on Dental Preclinical Crown Preparation Training,” Journal of Dental Education 88, no. 7 (2024): 983–993. [DOI] [PubMed] [Google Scholar]
33. Gratton D. G., Kwon S. R., Blanchette D., and Aquilino S. A., “Impact of Digital Tooth Preparation Evaluation Technology on Preclinical Dental Students' Technical and Self‐Evaluation Skills,” Journal of Dental Education 80, no. 1 (2016): 91–99. [PubMed] [Google Scholar]

[jdd70043-bib-0001] 1. Podhorsky A., Rehmann P., and Wöstmann B., “Tooth Preparation for Full‐Coverage Restorations—A Literature Review,” Clinical Oral Investigations 19, no. 5 (2015): 959–968. [DOI] [PubMed] [Google Scholar]

[jdd70043-bib-0002] 2. Falahchai M., Babaee Hemmati Y., Neshandar Asli H., and Rezaei E., “Effect of Tooth Preparation Design on Fracture Resistance of Zirconia‐Reinforced Lithium Silicate Overlays,” Journal of Prosthodontics 29, no. 7 (2020): 617–622. [DOI] [PubMed] [Google Scholar]

[jdd70043-bib-0003] 3. Nasir M. Q. and Kadhim A. J., “Marginal Adaptation of Different Monolithic Zirconia Crowns With Horizontal and Vertical Finish Lines: A Comparative In Vitro Study,” Journal of Dental Research, Dental Clinics, Dental Prospects 17, no. 4 (2023): 235–241. [DOI] [PMC free article] [PubMed] [Google Scholar]

[jdd70043-bib-0004] 4. Ashour A. M., El‐Kateb M. M., and Azer A. S., “The Effect of Two Preparation Designs on the Fracture Resistance and Marginal Adaptation of Two Types of Ceramic Crowns Using CAD/CAM Technology (In Vitro Study),” BMC Oral Health 24 (2024): 1065. [DOI] [PMC free article] [PubMed] [Google Scholar]

[jdd70043-bib-0005] 5. Findakly M. B. and Jasim H. H., “Influence of Preparation Design on Fracture Resistance of Different Monolithic Zirconia Crowns: A Comparative Study,” Journal of Advanced Prosthodontics 11 (2019): 324. [DOI] [PMC free article] [PubMed] [Google Scholar]

[jdd70043-bib-0006] 6. Luo B., Sun X., He L., Zhao L., Liu X., and Jiang Q., “Impact of Different Axial Wall Designs on the Fracture Strength and Stress Distribution of Ceramic Restorations in Mandibular First Molar,” BMC Oral Health 22 (2022): 549. [DOI] [PMC free article] [PubMed] [Google Scholar]

[jdd70043-bib-0007] 7. Motta A. B., Pereira L. C., Duda F. P., and Anusavice K. J., “Influence of Substructure Design and Occlusal Reduction on the Stress Distribution in Metal Ceramic Complete Crowns: 3D Finite Element Analysis,” Journal of Prosthodontics 23 (2014): 381–389. [DOI] [PubMed] [Google Scholar]

[jdd70043-bib-0008] 8. Zidan O. and Ferguson G. C., “The Retention of Complete Crowns Prepared With Three Different Tapers and Luted With Four Different Cements,” Journal of Prosthetic Dentistry 89 (2003): 565–571. [DOI] [PubMed] [Google Scholar]

[jdd70043-bib-0009] 9. Rashid N., Talib M., Ali W., Jaafar A., and Alaudding M., “An Evaluation of Full Coverage Crown Preparation: An Institutional Analysis,” Journal of Clinical and Diagnostic Research 14 (2020): 35–39. [Google Scholar]

[jdd70043-bib-0010] 10. Silvestri F., Odisho N., Kumar A., and Grigoriadis A., “Examining Gaze Behavior in Undergraduate Students and Educators During the Evaluation of Tooth Preparation: An Eye‐Tracking Study,” BMC Medical Education 24, no. 1 (2024): 1030. [DOI] [PMC free article] [PubMed] [Google Scholar]

[jdd70043-bib-0011] 11. Okuyama Y., Kasahara S., and Kimura K., “Quantitative Evaluation of Axial Wall Taper in Prepared Artificial Teeth,” Journal of Oral Science 47, no. 3 (2005): 129–133. [DOI] [PubMed] [Google Scholar]

[jdd70043-bib-0012] 12. Noonan J. E. Jr and Goldfogel M. H., “Convergence of the Axial Walls of Full Veneer Crown Preparations in a Dental School Environment,” Journal of Prosthetic Dentistry 66, no. 5 (1991): 706–708. [DOI] [PubMed] [Google Scholar]

[jdd70043-bib-0013] 13. Yoon S. S., Cheong C., Preisser J., Jun S., Chang B. M., and Wright R. F., “Measurement of Total Occlusal Convergence of 3 Different Tooth Preparations in 4 Different Planes by Dental Students,” Journal of Prosthetic Dentistry 112, no. 2 (2014): 285–292. [DOI] [PubMed] [Google Scholar]

[jdd70043-bib-0014] 14. Strain K. J., Mackie J., Bonsor S. J., and Macfarlane T. V., “Crown Taper Angles Achieved by Dental Students: A Systematic Review,” Journal of Dental Education 82, no. 11 (2018): 1203–1212. [DOI] [PubMed] [Google Scholar]

[jdd70043-bib-0015] 15. Al‐Omari W. M. and Al‐Wahadni A. M., “Convergence Angle, Occlusal Reduction, and Finish Line Depth of Full‐Crown Preparations Made by Dental Students,” Quintessence International 35, no. 4 (2004): 287–293. [PubMed] [Google Scholar]

[jdd70043-bib-0016] 16. Moskowitz M. E., Loft G. H., and Reynolds J. M., “Using Irreversible Hydrocolloid to Evaluate Preparations and Fabricate Temporary Immediate Provisional Restorations,” Journal of Prosthetic Dentistry 51, no. 3 (1984): 330–333. [DOI] [PubMed] [Google Scholar]

[jdd70043-bib-0017] 17. Gardner L. K., Rahn A. O., Parr G. R., and Richardson D. W., “Using a Tooth‐Reduction Guide for Modifying Natural Teeth,” Journal of Prosthetic Dentistry 63, no. 6 (1990): 637–639. [DOI] [PubMed] [Google Scholar]

[jdd70043-bib-0018] 18. Oh W.‐S., Saglik B., and May K B., “Tooth Reduction Guide Using Silicone Registration Material Along With Vacuum‐Formed Thermoplastic Matrix,” Journal of Prosthodontics 19, no. 1 (2010): 81–83. [DOI] [PubMed] [Google Scholar]

[jdd70043-bib-0019] 19. Stoilov M., Trebess L., Klemmer M., Stark H., Enkling N., and Kraus D., “Comparison of Digital Self‐Assessment Systems and Faculty Feedback for Tooth Preparation in a Preclinical Simulation,” International Journal of Environmental Research and Public Health 18, no. 24 (2021): 13218. [DOI] [PMC free article] [PubMed] [Google Scholar]

[jdd70043-bib-0020] 20. Dobroś K., Hajto‐Bryk J., and Zarzecka J., “Application of 3D‐Printed Teeth Models in Teaching Dentistry Students: A Scoping Review,” European Journal of Dental Education 27, no. 1 (2023): 126–134. [DOI] [PubMed] [Google Scholar]

[jdd70043-bib-0021] 21. Del Hougne M., Behr G., Schmitter M., and Höhne C., “3D Printed Teeth With Adhesive Bridge Preparation Guide,” Scientific Reports 14, no. 1 (2024): 22017. [DOI] [PMC free article] [PubMed] [Google Scholar]

[jdd70043-bib-0022] 22. Chaudhari P. K., Dhillon H., Dhingra K., and Alam M. K., “3D Printing for Fostering Better Dental Education,” Evidence‐Based Dentistry 22, no. 4 (2021): 154–155. [DOI] [PubMed] [Google Scholar]

[jdd70043-bib-0023] 23. Höhne C., Dickhaut N., and Schmitter M., “Introduction of a New Teaching Concept for Dentin Post Preparation With 3D Printed Teeth,” European Journal of Dental Education 24, no. 3 (2020): 499–506. [DOI] [PubMed] [Google Scholar]

[jdd70043-bib-0024] 24. Höhne C., Rammler T., and Schmitter M., “3D Printed Teeth With Included Veneer Preparation Guide,” Journal of Prosthodontics 30, no. 1 (2021): 51–56. [DOI] [PubMed] [Google Scholar]

[jdd70043-bib-0025] 25. Kim Y.‐K., Kim J.‐H., Jeong Y., Yun M.‐J., and Lee H., “Comparison of Digital and Conventional Assessment Methods for a Single Tooth Preparation and Educational Satisfaction,” European Journal of Dental Education 27, no. 2 (2023): 262–270. [DOI] [PubMed] [Google Scholar]

[jdd70043-bib-0026] 26. Chen J., Luo Y., Li H., et al., “Evaluating the Effectiveness of a Novel Digital Evaluation Technology on Dental Preclinical Crown Preparation Training,” Journal of Dental Education 88, no. 7 (2024): 983–993. [DOI] [PubMed] [Google Scholar]

[jdd70043-bib-0027] 27. Mahrous A., Elgreatly A., Qian F., and Schneider G. B., “A Comparison of Pre‐Clinical Instructional Technologies: Natural Teeth, 3D Models, 3D Printing, and Augmented Reality,” Journal of Dental Education 85, no. 11 (2021): 1795–1801. [DOI] [PubMed] [Google Scholar]

[jdd70043-bib-0028] 28. Robles M., Jurado C. A., Azpiazu‐Flores F. X., Villalobos‐Tinoco J., Afrashtehfar K. I., and Fischer N. G., “An Innovative 3D Printed Tooth Reduction Guide for Precise Dental Ceramic Veneers,” Journal of Functional Biomaterials 14, no. 4 (2023): 216. [DOI] [PMC free article] [PubMed] [Google Scholar]

[jdd70043-bib-0029] 29. Sartori N., Ghishan T., O'neill E., Hosney S., and Zoidis P., “Digitally Designed and Additively Manufactured Tooth Reduction Guides for Porcelain Laminate Veneer Preparations: A Clinical Report,” Journal of Prosthetic Dentistry 131, no. 5 (2024): 768–773. [DOI] [PubMed] [Google Scholar]

[jdd70043-bib-0030] 30. Da Silva B. P., Stanley K., and Gardee J., “Laminate Veneers: Preplanning and Treatment Using Digital Guided Tooth Preparation,” Journal of Esthetic and Restorative Dentistry 32, no. 2 (2020): 150–160. [DOI] [PubMed] [Google Scholar]

[jdd70043-bib-0031] 31. Puri N., Atria P. J., Oquendo A., Blatz M. B., and Sampaio C. S., “A Fully Digital Workflow Involving 3D Printed Tooth Reduction Guides and Injection Resin‐Indexes to Restore an Impacted Canine,” Journal of Esthetic and Restorative Dentistry 36, no. 10 (2024): 1388–1395. [DOI] [PubMed] [Google Scholar]

[jdd70043-bib-0032] 32. Chen J., Luo Y., Li H., et al., “Evaluating the Effectiveness of a Novel Digital Evaluation Technology on Dental Preclinical Crown Preparation Training,” Journal of Dental Education 88, no. 7 (2024): 983–993. [DOI] [PubMed] [Google Scholar]

[jdd70043-bib-0033] 33. Gratton D. G., Kwon S. R., Blanchette D., and Aquilino S. A., “Impact of Digital Tooth Preparation Evaluation Technology on Preclinical Dental Students' Technical and Self‐Evaluation Skills,” Journal of Dental Education 80, no. 1 (2016): 91–99. [PubMed] [Google Scholar]

PERMALINK

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