Tooth Reduction Research Articles

Zirconia Crowns as an Advanced Solution for Pediatric Dental Caries: A Comprehensive Review of Biochemical Considerations and Management Approaches

Background: Pediatric dental caries is a prevalent issue, necessitating effective restorative solutions. Zirconia crowns have emerged as a promising option due to their superior mechanical properties and aesthetics compared to traditional materials. Understanding the biochemical considerations and management approaches associated with zirconia crowns is essential for optimizing their use in pediatric dentistry. Methods: This comprehensive review analyzes recent literature on zirconia crowns, focusing on their composition, mechanical properties, translucency, preparation techniques, and bonding characteristics. A systematic search was conducted across databases such as PubMed, Scopus, and Embase, retrieving studies from 2000 to 2023 that detail advancements in zirconia materials and their clinical applications. Results: The review highlights that monolithic zirconia crowns offer exceptional strength, aesthetics, and biocompatibility, making them suitable for pediatric patients. Advances in zirconia formulations have enhanced translucency and reduced the need for extensive tooth reduction. However, challenges remain in achieving optimal bonding strength due to zirconia's low surface energy. Surface treatments and the use of adhesive cements containing phosphate monomers have shown promise in improving adhesion. Conclusion: Zirconia crowns represent a significant advancement in pediatric restorative dentistry, combining durability and aesthetic appeal. Ongoing research is needed to refine bonding techniques and improve clinical outcomes. The integration of zirconia crowns into pediatric dental practice requires a thorough understanding of their properties and the implementation of effective management strategies

Computer-Assisted Porcelain Laminate Veneer Preparation: A Scoping Review of Stereolithographic Template Design and Fabrication Workflows.

Computer-assisted preparation of porcelain laminate veneers (PLVs) using stereolithographic templates has been developed to enhance the accuracy of tooth preparation. However, the digital workflows involved in guided PLV preparation remain inconsistently defined across various practices. Therefore, this scoping review aimed to examine publications on computer-assisted PLV preparation to identify the key stage of digital workflows involved in designing and fabricating stereolithographic templates, as well as to highlight the limitations of various template designs. This scoping review aimed to identify publications on digital workflows for designing and fabricating stereolithographic templates in computer-assisted porcelain laminate veneer preparation. A systematic search on MEDLINE/PubMed, Web of Science and Scopus identified English-language articles published from 2014 to March 2024. Eligible articles focused on digitally designed and fabricated tooth reduction templates for porcelain laminate veneers, excluding conventional tooth preparation procedures for tooth reduction assessment. Seven clinical reports were included, demonstrating various 3D data acquisition techniques for virtual patient generation. All articles described virtual diagnostic wax-ups on digital casts, with two using a virtual articulator. Only five articles documented chair-side mock-ups with resin trial restorations to evaluate planned dental esthetics. Additionally, virtual tooth preparation prior to templates design was included in only four articles. The templates were designed using different software and ranged from simple designs with access windows to complex stacked templates with rotary instrument sleeved windows. Each template design had limitations affecting tooth reduction accuracy. All articles reported printing templates in clear acrylic resin using different technologies. In conclusion, the review highlights a lack of standardization in the digital workflow for designing stereolithographic templates for PLVs. Establishing a sound protocol for designing the tooth reduction templates is essential to ensure the accuracy and consistency of veneer preparation.

The role of orthodontics in the management of tooth wear.

Pathological tooth wear is a dental problem that affects all age groups and appears to be increasing in prevalence. A subset of these patients may benefit from a combination of orthodontic and restorative care which will be discussed in this article. Orthodontics can help to create the necessary vertical, anterior-posterior and mesio-distal space for restorative work, reducing the need for tooth reduction and lessening the biological costs of restorative care, helping to reposition the gingival margins where this impacts upon aesthetics, as well as correcting co-existing malocclusion.

Management and Outcomes of Severe Submergence in Second Premolar

General Background: The early loss of primary molars is a prevalent dental issue that can lead to significant occlusal disturbances, including space reduction and misalignment of permanent teeth. Specific Background: Submergence of the second permanent molar following premature exfoliation of primary molars exacerbates these issues, complicating the eruption pattern and dental arch integrity. Knowledge Gap: Despite existing treatment modalities, there is limited evidence on the effectiveness of specific appliances in managing severe submergence cases in pediatric patients. Aims: This study aims to evaluate the efficacy of the Gerber Space Regainer in restoring lost space and correcting the alignment of submerged second premolars in a pediatric patient. Results: A 10-year-old patient experiencing significant space loss due to premature exfoliation of tooth 85 was treated with a Gerber Space Regainer. Over a 7-week period, the appliance successfully regained 8 mm of space, with notable uprighting of the affected premolar, achieving complete recovery of the dental arch. Novelty: This case report highlights the practical application and success of the Gerber Space Regainer, emphasizing its efficiency in a short time frame, which has not been extensively documented in similar clinical scenarios. Implications: The findings suggest that the Gerber Space Regainer is an effective and reliable option for managing complex orthodontic cases involving submergence and space loss, contributing to the enhancement of treatment protocols in pediatric dentistry. Highlights: Effective space recovery: The Gerber Space Regainer successfully restored 8 mm of lost dental arch space in 7 weeks. Improved alignment: The treatment led to the uprighting of the submerged second premolar, ensuring proper occlusion. Pediatric applicability: The appliance demonstrated high efficiency and compliance in a young patient, showcasing its potential in pediatric cases. Keywords: Premature Loss, Space Regainer, Submergence, Second Premolar, Eruption Disturbance

A digital workflow for full-mouth rehabilitation using CAD-CAM tooth reduction template.

A digital workflow is presented for multiple transfers of targeted jaw relation and restorative spaces from interim to definitive restorations in patients with severe tooth wear. Following analysis of the targeted restorative space, segmented arch stereolithographic templates were digitally created and fabricated for precise control of reduction depth. Then, the jaw relation was transferred from the initially determined stabilization splint to the temporary fixed restoration and definitive restoration by using a digital articulator. This digital approach yielded a stabilized jaw relationship and restorative spaces transferring effect throughout successive stages of occlusal reconstruction resulting in satisfactory prosthetic outcomes.

Effect of Nitrofurantoin Versus Calcium Hydroxide used as an Intracanal Medicament on Bacterial Load Reduction in Teeth with Necrotic Pulp: A Randomized Clinical Trial

Effect of Nitrofurantoin Versus Calcium Hydroxide used as an Intracanal Medicament on Bacterial Load Reduction in Teeth with Necrotic Pulp: A Randomized Clinical Trial

Effectiveness of maxillary arch expansion using clear aligners in adult patients: a systematic review and meta-analysis

Abstract Introduction Invisalign, introduced by Align Technology, Inc. in 1997, is a system of clear plastic aligners that provides aesthetic orthodontic treatment plus treatment customisation. Created using impressions or intraoral digital scans, patients wear and sequentially exchange removable, 0.75 mm thick polyurethane appliances. The aligners improve smile appearance, correct dentoalveolar posterior crossbites, increase arch length, relieve crowding, and provide more space for tooth alignment. Dentoalveolar expansion is a preferred alternative to interproximal tooth reduction when treating a patient using the Invisalign clear appliance. Materials and methods The present review systematically searched electronic databases for prospective and retrospective studies on dentoalveolar expansion using clear aligner therapy in human subjects. The quality of the studies was assessed using the revised Cochrane risk of bias tool. Results A high risk of bias was noted in the systematic evaluation of five human trials comprising 254 healthy individuals. The most frequent cause of bias was found to be patient selection. Patient attrition was caused by age-related issues, inadequate compliance, and the lack of blinded outcome evaluation, underscoring the need for better research protocols. Conclusion The present study examined maxillary arch expansion in adult patients who received clear aligner therapy. It was found that the efficiency of expansion at the completion of an aligner treatment sequence may be marginally better than at the completion of an expansion treatment due to the hysteresis (the difference between the predicted and actual results of expansion) of Invisalign appliances, which enhances effectiveness and generates the greatest expansion in the first and second premolar region.

A fully digital workflow involving 3D printed tooth reduction guides and injection resin-indexes to restore an impacted canine.

The present clinical report describes a long-term temporary restorative approach using injectable composite to reshape a canine into a central incisor, within the context of an ongoing orthodontic treatment. This treatment protocol describes a fully-digital workflow, incorporating digital designed and 3D printed diagnostic wax up, reduction guides and resin-injection index. Effective planning is important when aiming to deliver a comprehensive and multidisciplinary workflow, and digital tools serve as invaluable aids. The use of a fully digital workflow in a comprehensive dental treatment resulted in a predictable and successful outcome for a restoration of a canine that was transformed into a central incisor. This approach highlights the efficacy of digital technology in achieving precise and successful dental restorations, emphasizing its significance in modern dental practice.

Comparative Study of Mesiodistal Crown Dimensions and Tooth Size Discrepancies of Thalassemia and Control Iraqi Patients

Aims: To find differences in mesiodistal tooth width in Iraqi B thalassemia compared with normal individuals. Setting and design: 44 subjects, 22 thalassemia (11 males, 11 females) (12.5–22) years, and 22 control (11 males, 11 females) 14–23 years. Methods and Material: Registrations of MD for maxillary and mandibular teeth from the first molar on one side to analogous tooth on the other side were done. Statistical analysis: Mean, standard deviation and 2-sampled t-test were used. Results: In both groups, males’ crown size was greater than females. In the study group largest gender variances appear in the maxillary molars, mandibular molar, maxillary central and maxillary canine respectively. In control, the greatest sexual difference is present in the maxillary first premolar followed by the mandibular second premolar. The means of mesiodistal in both sexes in thalassemia were smaller than in control except in male maxillary central and lateral and female maxillary lateral incisor. In the maxilla, a significant decrease in mesiodistal thalassemia is present in canine and second premolar in both sexes. In the mandible, a significant decrease in thalassemia was present in all comparisons in both genders in comparison with the control. The greatest mesiodistal difference in the mandibular male is present in the first molar, first premolar, second premolar, canine, lateral and central incisor respectively. In female mandibular teeth, the greatest difference is present in the first molar followed by the first premolar, second premolar, canine, lateral incisor and central incisor. Conclusions: Means mesiodistal dimensions in thalassemia show a significant reduction in mandibular teeth and maxillary canine and second premolar in both genders.

Comparison of digitally assessed quality of posterior crown preparations performed with and without previous practice on patient-specific three-dimensional-printed teeth models.

Three-dimensional (3D)-printing technology can provide customizable simulations, but its effects on patient care quality have not been well studied. This study aimed to assess the impact of practicing with patient-specific 3D-printed teeth models on the quality of patients' dental preparations performed by students transitioning to clinical training. Accordingly, the quality of posterior crown preparations was evaluated by objectively analyzing digital scans and grades in two groups: the study group, which practiced beforehand with patient-specific 3D-printed teeth models, and the control group, which did not practice with these models. All 78 fourth-year dental students who had just finished their fixed prosthodontics course at the simulation laboratory with training on phantom heads and without previous clinical experience in crown preparations were invited to participate in the study. Sixty-eight agreed to take part and were randomly divided into a study group that practiced crown preparations on 3D-printed models of their own patient's teeth and a control group that did not practice with 3D-printed models and started their clinical work straightforwardly after simulation training. Students completed validated perception questionnaires on self-confidence and clinical skills before and after the protocol, which were compared using a chi-squared test. Crown preparations performed on 3D-printed models and then on patients were digitally scanned and objectively graded by prepCheck software for critical parameters, such as undercuts, taper, and occlusion reduction. Non-parametric tests were used to compare preparations on 3D-printed models and on patients performed by the study group and those on patients made by the control group. Initially, both groups reported similar perceptions of self-confidence and clinical skills levels. The study group significantly improved both aspects after the protocol. Analysis of the scanned preparations demonstrated that the study group removed less tooth structure from actual patients than from the initial 3D-printed models. In contrast, the control group showed excess occlusal clearance in their patients compared to the study group. Practicing patient-specific 3D-printed teeth before performing procedures clinically appears to enhance preparation quality and minimize unnecessary tooth reduction in early clinical experiences.

Dentist Dilemmas on Replacing Single Missing Teeth; Implant versus Fixed Partial Denture – A Survey among Practicing Dentists

ABSTRACT Background: Dental implant and fixed bridges are the common and acceptable means of prosthetic restoration of missing tooth. Although each is a viable treatment option, the implant restoration has definite advantages. A major shortcoming of the fixed bridge is the significant tooth reduction of the abutments. This study aimed to know the reasons that make some dentists choose a dental bridge in the edentulous area with adjacent sound teeth over the implant in cases suitable for implant. Materials and Methods: An observational questionnaire study was conducted between January and May 2022. An online questionnaire was sent to qualified dentists practicing in different cities of Saudi Arabia. Absolute frequencies were used to describe the data. Results: A total of 602 dentists received the questionnaire, and 430 responded, resulting in a response rate of 71.7%. The majority of responders (98%) recommended implant as a first choice to replace missing tooth when both implant and fixed bridge can be used in case of sound abutments. However, they mentioned factors such as cost of treatment, patient wishes, and patient’s medical condition act as an obstacle or difficulty to support their use of the implant in some cases. Conclusions: More efforts should be done to encourage dentists to select appropriate treatment option of proven scientific basis without any bias. Patients should be given more information about the advantages of implant over fixed partial denture and should be motivated. Finally, more support from implant companies should be encouraged as well as more knowledge and skill about implant dentistry should be gives during undergraduate courses.

Preparation of ultrathin translucent zirconia laminate veneers using 3D printing reduction guides

Minimizing and controlling the amount of tooth reduction during the preparation of ultrathin laminate veneers is a challenge for minimally invasive dentistry. The use of reduction guides is advised to reach the optimal space required for the definitive restoration without excessive reduction. The digital production of a reduction guide used to control tooth preparation for ultrathin laminate veneers is described.

Effect of Occlusal Reduction on Alleviating Pain in Symptomatic Apical Periodontitis

OBJECTIVE: To evaluate pain relief in response to occlusal reduction in teeth with symptomatic apical periodontitis METHODOLOGY:A randomized controlled trial was done at department of Operative Dentistry and Endodontics, PIMS Hospital, Islamabad, Pakistan 27th May 2019 to 30th May 2020 on 166 patients suffering from irreversible pulpitis with symptomatic apical periodontitis were included in the study. After consent, Visual Analogue Scale (VAS) was used to document preoperative pain levels. Pulpectomy was done and patients were randomly divided into Group A (without occlusal reduction) and Group B (with 1-1.5mm occlusal reduction). Mean pain scores of Group A and Group B were compared at 24hrs, 72 hours and seventh day using T-test RESULTS: There was a significant difference in mean pain score (p=0.0001) post-pulpectomy between the teeth with and without occlusal reduction. CONCLUSION: The teeth that underwent occlusal reduction after pulpectomy showed lower mean pain levels compared to the non-reduction group. KEYWORDS: Occlusal reduction, apical periodontitis, irreversible pulpitis, pulpectomy, root canal therapy

Objective quantitative digital evaluation of crown preparation using intraoral optical scanner: Novel preclinical teaching method.

Adequate preclinical training in dentistry is crucial for students before engaging in patient treatment. Constructive feedback from the instructors plays a pivotal role in guiding the students to master skills, boost confidence, and above all ensure patient safety. This manuscript introduces a new method employing intraoral scanners as digital tools to provide objective and quantitative feedback for crown preparation evaluation in preclinical prosthodontics. Initial reference scan before preparation on typodont and preparation scan after crown preparation was obtained. Utilizing the patient monitoring feature in Trios 3 scanner (3Shape, Copenhagen, Denmark) superimposition of two scans was performed. The method enabled a comprehensive quantitative preparation assessment compared to the tooth pre-preparation. This includes tooth reduction in any axis, abutment height measurement, evaluation of the status of adjacent teeth after preparation, and proposed capability for estimating the convergence angle. The method enabled a subjective quantitative evaluation of crown preparation in phantom model. This method requires no additional hardware or software beyond the basic functions embedded in the intraoral scanner. Implementation of this function not only facilitates feedback and self-evaluation for students during preclinical teaching but also enhances their proficiency in using intraoral scanners in clinical practice in perspective. Key words:Dental education, prosthodontics, intraoral scanner, feedback, self-assessment.

Evaluation and Comparison of Thermal Changes in the Pulp Chamber in Different Inter Proximal Reduction Techniques: An In-vitro Study

Introduction: Interproximal reduction (IPR) is a common orthodontic treatment procedure that is used which involves tooth reduction, anatomic recontouring, and protecting permanent teeth proximal enamel surfaces. Sheridan described the air-rotor stripping technique as an alternative to extraction in borderline cases. Though there are many studies, it was not clearly differentiated regarding the pulpal temperature changes during IPR.
 Materials and Methods: In this in vitro study, 63 extracted human premolar teeth were randomly assigned to three groups (n=21). Group-1 (Strauss diamond stripping bur) at high speed above 20,000 rpm, Group-2 (Manual Handheld metal stripper). Group-3 (Strauss diamond stripping disc) at a low speed below 15,000 rpm. The average mean temperature is assessed for each tooth during various techniques using K-type thermocouple. During the procedure, the thermometer display was covered, and the temperature was revealed after all the stripping procedures had already been performed. Data were analyzed using IBM SPSS version 20 software. Descriptive statistics, one way analysis of variance with Tukey’s post hoc tests were done to analyze the study data.
 Results: The mean rise in temperature was highest with disc & micromotor (4.3ºC) followed by airotor & bur (4.02ºC) and manual method (2.52ºC) (p ≤ 0.05).
 Conclusion: There was an increase in the pulpal temperature using diamond stripping disc with micromotor followed by the airotor and bur, manual hand held stripping.

Comparative Evaluation of Bacterial Reduction by Laser-Activated Irrigation Technique (LAI) With Conventional Needle Irrigation (CNI) in Single-Rooted Teeth With Pulpal Necrosis: A Single-Blinded Randomized Controlled Trial.

Aim To compare the bacterial reduction in single-rooted teeth with pulpal necrosis after laser-activated irrigation technique(LAI) and conventional needle irrigation (CNI). Methodology In this clinical trial (CTRI/2021/09/047767), 32 patients with pulpal necrosis were enrolled. Under complete aseptic conditions, access cavity preparation was done and the baseline sample S1 was collectedfrom the root canal using paper points. After chemo-mechanical preparation they were allocated into two groups, following block randomization; Group A - CNI with 27 gauge side-vented needle, Group B - LAI with pulsed Er,Cr:YSGG (erbium, chromium:yttrium-scandium-gallium-garnet) (2780 nm) laser. After irrigant activation, canals were dried and a second sample S2 was taken using paper points. Microbial analysis using quantitative polymerase chain reaction (qPCR) was done to quantify the bacterial reduction among the two groups. Inter-group and intra-group analysis was done using the independent student t-test and Bonferroni test, respectively. The data was represented in terms of quantification cycle (Cq) values, which are inversely proportional to the microbial count. Results There was no significant difference in S1 between the two groups (mean difference=0.0205; p=0.912). There was a significant difference in S2 between the two groups for the organisms (mean difference=0.8042; p=0.000). The mean percentage of bacterial reduction in CNI was 10.82% and in LAI it was 25.92%. There was a significant difference in S1 through S2 within the two groups for the organisms (p=0.000). The mean difference of Cq value is high for LAI compared to CNI (1.3494). The fold change was calculated by taking the ΔCq value and ΔΔCq value after the logarithmic transformation of the Cq value. LAI showed lower levels of DNA at S2 similar to CNI. There is no significant difference in mean fold change between CNI and LAI (p=0.564). Conclusion This clinical trial concluded that both LAI and CNI were effective in bacterial reduction. There was greater bacterial reduction with LAI (25.92%) than with the CNI (10.82%) in single-rooted teeth with pulpal necrosis using qPCR analysis.

Size does matter: metric variability of the upper second molars and differentiation of the Middle and Late Pleistocene Homo in Eurasia

Dental data are one of the most important sources of information on the evolution of ancient hominids. It preserves information about both the early stages of ontogenesis and the postnatal period of life. It is generally accepted that one of the main evolutionary trend within the genus Homo over the past two million years was reduction of teeth size. This trend substantially accelerated in modern Homo sapiens during the Upper Paleolithic and Neolithic. It is assumed that a number of factors could influence the teeth reduction process. However, no detailed understanding of its patterns, limits and chronological and territorial variability has been revealed so far. In this study, we analyze the variability of the upper second molar sizes in Neanderthals, Denisovans, Homo antecessor, Middle Pleistocene Homo from Sierra de Atapuerca (Gran Dolina), Homo erectus, Middle and Late Pleistocene Homo from China other than H. erectus, and compare them with the characteristics of the modern H. sapiens. The main goal of our analysis was to identify local chronological and geographical patterns in the evolution of the size of the second upper molars and assess their compliance with the general epochal trend. The results of the analysis showed that before the appearance of the Upper Paleolithic H. sapiens, two distinct local trends existed on the territory of Eurasia. The first trend, which can be detected in the European pre-sapiens humans, was a decrease in the molar size of the upper second molars. The second one, which got spread in the Middle Pleistocene in Asia, on the contrary, consisted of a sharp increase of the molar size, which formed the morphological specificity of the Denisovan lineage. No stable geographic differentiations of the size of the upper second molars are observed within H. sapiens sample.

Treatment of Oral Disease in Eight Pet Pot-Bellied Pigs (Sus scrofa domesticus): A Case Series.

Evidence of porcine oral pathology in client-owned domestic pigs has been reported in recent literature. The most common abnormalities are missing teeth and periodontal disease. This case series reviews the diagnosis and treatment of dental disease in 8 pet Vietnamese Pot-Bellied Pigs (Sus scrofa domesticus) over a 6-year period (2015-2021). Inclusion criteria included pigs over 1 year of age that had at least 2 sequential visits involving photographs, full-mouth intraoral radiographs, and dental charting. Eight pigs were identified for study inclusion. The study population included 4 castrated males, 3 spayed females, and 1 intact female. The 8 subjects had a total of 28 visits. Fifty-five intraoral dental extractions were performed and complete healing of 44 extraction sites was observed (11 sites were lost to follow up). Canine tooth reduction was performed on 52 tusks in 7 pigs with exposure of 1 pulp that was treated by partial pulpectomy and direct pulp capping. Restoration of carious lesions was performed on 4 teeth. The most commonly extracted teeth were the right and left maxillary first molars (10 of 47 teeth). Reasons for tooth extraction included: periodontal disease, complicated crown fracture, nonvital +/- periapical pathology, and persistent deciduous teeth. Additional treatments ranged from type 1 crown lengthening with restoration of carious lesions, tusk trimming, closed and open root planing, dental extractions, ultrasonic scaling, and polishing. This article stresses the importance of routine dental healthcare and early intervention for periodontal disease in pigs.

From teeth to pad: tooth loss and development of keratinous structures in sirenians.

Sirenians are a well-known example of morphological adaptation to a shallow-water grazing diet characterized by a modified feeding apparatus and orofacial morphology. Such adaptations were accompanied by an anterior tooth reduction associated with the development of keratinized pads, the evolution of which remains elusive. Among sirenians, the recently extinct Steller's sea cow represents a special case for being completely toothless. Here, we used μ-CT scans of sirenian crania to understand how motor-sensor systems associated with tooth innervation responded to innovations such as keratinized pads and continuous dental replacement. In addition, we surveyed nine genes associated with dental reduction for signatures of loss of function. Our results reveal how patterns of innervation changed with modifications of the dental formula, especially continuous replacement in manatees. Both our morphological and genomic data show that dental development was not completely lost in the edentulous Steller's sea cows. By tracing the phylogenetic history of tooth innervation, we illustrate the role of development in promoting the innervation of keratinized pads, similar to the secondary use of dental canals for innervating neomorphic keratinized structures in other tetrapod groups.

Effect of a digital assessment system for the preclinical tooth preparation of metal-ceramic crowns: A pilot study

Tooth preparation is a fundamental aspect of prosthodontics and serves as a focal point in preclinical courses. Conventional pedagogy relies heavily on the expertise of instructors, whereas digital technology has the potential to offer instantaneous feedback. The efficacy of a digital assessment system in comparison with traditional teaching methods remains uncertain. The purpose of this study was to compare the training effects of traditional assessment and digital evaluation on tooth preparations for the metal-ceramic crowns performed by preclinical students on the convergence angle and tooth reduction. A total of 40 predoctoral students were randomly divided into the digital group and the traditional group to complete tooth preparation for a metal-ceramic crown on a left mandibular first molar. Students in the traditional group were taught by an experienced instructor, while the digital group students were trained by an objective digital assessment system without instructor guidance. Each student completed the tooth preparation in 20min, received feedback according to the respective training methods, and later prepared another tooth. In this way, all students completed 4 tooth preparations in 2 weeks. All preparations were evaluated by an optical scanner. Parameters for comparing the digital group with the traditional group were the convergence angle and reduction at different stages. Questionnaires on the digital training system were answered by the students of the digital group. The t tests or Wilcoxon signed rank tests and chi-squared tests were used to analyze the differences between the 2 groups (α=.01). A decreasing trend in convergence angle was seen in both groups, but the 2 groups were statistically similar (P>.01). After training, a decreasing trend was seen in under-reduction and overreduction on 5 surfaces in the digital group. Conversely, in the traditional group, a noteworthy increase was seen in under-reduction on the distal surface (P=.002). Nevertheless, no significant difference was found between the 2 groups (P>.01). According to the results of the questionnaire, over 80% of the students had a positive attitude toward the digital assessment system, and more than 80% of the students expressed their interest in the digital assessment system for tooth preparation training. Traditional teaching and digital feedback provided similar training effects to improve the quality of tooth preparations for preclinical dental students.