OBJECTIVES:This study investigated the effects of the axiopulpal line angle design and different cement space settings on the adaptation of indirect ceramic inlays. METHODS:Standardized Class II cavities were prepared, scanned, and used to design ceramic inlays fabricated with a 5-axis milling unit. Based on the axiopulpal line angle design, the cavities were classified into sharp, rounded, and beveled groups. Each group was further subdivided (n = 10) according to cement space settings as 50, 100, and 50 µm selectively increased to 100 µm at the axiopulpal line angle (50/100 µm). Milling accuracy, occlusal fit, and internal adaptation were examined using the triple-scan method. Statistical analyses were conducted using two-way analysis of variance with Tukey's post hoc test (α = 0.05). RESULTS:In the sharp line angle group, the axiopulpal line angle region was under‑milled, resulting in positive discrepancies. The 50 µm cement space group demonstrated greater occlusal discrepancies regardless of the axiopulpal line angle design (p < 0.05). Even with increased cement space settings, the sharp line angle group exhibited statistically significant occlusal discrepancies. Nonsharp line angle groups demonstrated significantly smaller internal gaps and greater cement space uniformity when a cement space of 100 or 50/100 µm was applied (p < 0.05). CONCLUSIONS:Nonsharp axiopulpal line angle designs improved milling accuracy and occlusal seating, resulting in smaller and more uniform internal gaps in the 100 and 50/100 µm cement space setting. CLINICAL SIGNIFICANCE:Nonsharp axiopulpal line angle designs improve milling accuracy and seating in CAD/CAM ceramic inlays. When combined with a 100 µm cement space or selectively increased cement space at the axiopulpal line angle area, thinner and more uniform cement gaps are achieved, which may improve clinical fit and long-term restoration stability.

Objectives This study aimed to evaluate the influence of adjacent restorative material and interproximal distance on the accuracy of digital impressions of inlay cavities obtained using an intraoral scanner. Methods A disto-occlusal inlay cavity was prepared on a mandibular right first molar model, and digital scans were performed using a CEREC Primescan (Dentsply Sirona). The adjacent restorative materials used were Lava (3M ESPE), ENAMIC (VITA Zahnfabrik), Celtra Duo (Dentsply Sirona), and DMAX (DMAX), and the interproximal distances were set to 0.6 mm, 0.8 mm, and 1.0 mm. The obtained scan data were analyzed using GOM Inspect software (GOM GmbH). Results Trueness, maximum positive and negative deviations, and precision were significantly influenced by both the adjacent restorative material and the interproximal distance, while their interaction showed a significant effect only on precision. Celtra Duo demonstrated the highest trueness, with mean deviation values decreasing from 7.8 μm at a 0.6 mm interproximal distance to 7.3 μm at 1.0 mm. ENAMIC showed the best precision, presenting mean deviations of 2.6 μm at 0.6 mm, 2.9 μm at 0.8 mm, and 2.4 μm at 1.0 mm. A narrow interproximal distance of 0.6 mm resulted in lower trueness, measured at 8.3 μm, and the highest precision deviation of 3.4 μm. In contrast, an interproximal distance of 1.0 mm yielded improved scan accuracy, with increased trueness and reduced precision variation. Conclusions Digital impression accuracy of inlay cavities was influenced by adjacent restorative material and interproximal distance, suggesting clinical consideration is needed in CAD/CAM workflows to optimize restoration fit.

The stamp technique is a simple method to reproduce occlusal morphology by creating an index before cavity preparation. This report presents two cases of mandibular second molars with deep occlusal caries but intact occlusal anatomy. A stamp was fabricated with flowable composite resin and applied to the final composite increment procedure. Both cases showed accurate anatomical reproduction, minimal finishing and polishing, and reduced chair time. The technique is particularly useful for Class I cavities with preserved occlusal surfaces, providing functional and esthetic benefits. Despite limitations in cases with lost occlusal anatomy or polymerization stress, the stamp technique is an efficient option that enhances clinical outcomes and patient satisfaction.

Background/purposeThis study assessed the ability of experimental materials consisting of dicalcium silicate (DCS) and tricalcium silicate (TCS) with nanosized particles to form intratubular crystals under phosphate-buffered saline (PBS) and the effect on dentin permeability reduction.Materials and methodsBy isolating the cervical part of the extracted premolars, 195 specimens were obtained. Two experimental materials (DCS/TCS and TCS) were applied to the dentin surface by brushing and stored in PBS (n = 65). Another 65 specimens were not treated. Each group was randomly divided into five subgroups based on the PBS immersion period (1, 15, 30, 60, and 90 days, n = 10). The dentin permeability was measured, and the hydraulic conductance, Lp (%), was calculated. After acid challenge with 1 M acetic acid, Lp (%) was remeasured. Data were analyzed using two-way analysis of variance and Fisher's least significant difference test (α = 0.05). Three specimens of each subgroup were longitudinally sectioned and examined using scanning electron microscopy and a field emission-electron probe micro analyzer.ResultsThe Lp (%) of the experimental groups gradually decreased over time (P < 0.05). The hydroxyapatite-like crystals that grew were observed and found to have a Ca/P ratio similar to that of hydroxyapatite. The crystals remained after the acid challenge, and the Lp (%) was not significantly different from that before acid treatment.ConclusionIntratubular crystals formed from the experimental materials consisted of DCS and TCS and were resistant to acid. These crystals significantly reduced dentin permeability.

Introduction The Quantitative Light-Induced Fluorescence (QLF) device provides both the visual information of crack lines on tooth surfaces and quantitative values for fluorescence reactions. The aim of this study was to evaluate the correlation and assess the usefulness of QLF quantitative values in pulp diagnosis of teeth with cracks. Methods Pulp diagnosis was performed on 76 teeth with cracks according to the American Association of Endodontics's guidelines, and their QLF images were captured. The crack lines of the QLF images were quantitatively analyzed using the QLF software CrazeLineWizard01. QLF quantitative values (ΔF: fluorescence loss unit, ΔFmax: maximum of fluorescence loss unit, ΔR: red fluorescence gain unit, ΔRmax: maximum of red fluorescence gain unit) according to the pulp diagnosis of teeth with cracks were analyzed using one-way ANOVA. Multinomial logistic regression analysis was conducted to calculate the prediction of pulp diagnosis on QLF quantitative values. The correlation between the predicted pulp diagnosis and the clinical pulp diagnosis was compared using Pearson's correlation coefficient. Results ΔF and ΔF max decreased with the progression of pulp disease in cracked teeth, while ΔR and ΔR max increased. Significant differences were found between irreversible pulpitis and pulp necrosis (p < 0.05). Pearson correlation coefficients between predicted and clinical pulp diagnosis based on multinomial logistic regression analysis of QLF quantitative values ranged from 0.699 to 0.806. The accuracy of prediction​​was up to 82.1 % for reversible pulpitis, 73.1 % for irreversible pulpitis, and approximately 80.0 % for pulp necrosis. Conclusions The quantitative values from the QLF device demonstrate its potential for predicting the severity of pulp disease caused by tooth cracks. Clinical significance The quantitative values of QLF images acquired with a QLF device, which provide visual information on crack lines of teeth through fluorescence reactions on the tooth surface, showed a significant correlation and predictive value for pulp diagnosis as pulp disease progressed in teeth with cracks.

PURPOSE:To evaluate the efficacy of copper-doped titanium dioxide (Cu-TiO₂) nanoparticles (NPs) in bleaching the stained teeth when subjected to hydrogen peroxide (H₂O₂) and blue light irradiation. METHODS:Cu-TiO₂ NPs were synthesized by mixing TiO₂ and Cu, followed by calcination. Their light absorbance was measured. Photocatalytic reactions were evaluated using methylene blue (MB), 3,3',5,5'-tetramethylbenzidine (TMB), and terephthalic acid (TA) assays. Color changes in stained teeth were monitored under various conditions, including the presence or absence of 3% H₂O₂ and light irradiation. Additionally, the cytotoxicity of Cu-TiO₂ NPs on normal oral cells (periodontal ligament fibroblast: PDLF) was evaluated. RESULTS:Unlike pristine TiO₂, Cu-TiO₂ exhibited a slightly increased absorbance in the 600-800 nm range due to the incorporated Cu. Cu-TiO₂ demonstrated high MB degradation and a marginal increase in peak intensity at 650 nm upon combined H₂O₂ and light irradiation. The TA assay showed a gradual increase in peak fluorescence intensity near 425 nm with increasing light exposure. Stained teeth treated concurrently with Cu-TiO₂ NPs, 3% H₂O₂, and laser irradiation exhibited significantly superior color changes. Importantly, the tested Cu-TiO₂ NPs displayed negligible toxicity to PDLF at concentrations up to 500 ppm. CLINICAL SIGNIFICANCE:Cu-TiO₂ NPs, when utilized with 3% H₂O₂ and blue laser, offer enhanced bleaching efficacy through photoinduced radical generation compared to 15% H₂O₂ alone, while maintaining negligible damage to normal oral cells at concentrations of 500 ppm or higher.

Purpose This study aims to develop a novel method for objectively assessing dental students' manual dexterity in tooth cavity preparation using 3D technology.Materials and Methods An artificial tooth model compatible with traditional dental simulators was created using 3D scanning and printing technology. The model was designed with a simplified cavity to assess students' manual dexterity in cavity preparation. To validate the new assessment model, it was tested on 10 undergraduate dental students. After the students prepared the cavities, the models were scanned again, and the resulting 3D data were analyzed using open-source software. The assessment score was calculated based on the volume of over-prepared and under-prepared areas.Results The 3D-printed tooth model was successfully integrated with traditional dental simulators, providing stability and consistency during cavity preparation practice. The assessment results revealed a range of performance levels, with scores ranging from 41.6 - 78.1, and an average score of 60.5. This variation highlights differences in students' manual dexterity and precision in cavity preparation.Conclusion The newly developed tooth model and analysis method successfully enabled the objective evaluation of students' manual dexterity in cavity preparation. This approach offers a standardised and cost-effective alternative to existing evaluation systems, enhancing the consistency and accuracy of assessments in dental education.

This study investigates the effects of dentin's drying time, roughness, and curing modes of resin cement on bond strength. Forty human teeth were divided into eight groups based on three experimental factors: dentin's roughness by 240-or 600-grit SiC paper (coarse or fine), dentin wetness with air-drying time (5-s or 10-s), and Single Bond Universal adhesive's curing mode by co-curing with RelyX Ultimate cement or light-curing separately (co-curing or light-curing). The micro-tensile bond strength of fifteen resin-dentin stikcs per groups was measured. Failure mode and adhesive layers were observed using stereoscopic and confocal laser scanning microscopy, respectively. The curing mode of the adhesive layer affected the bond strength of the dentin-resin cement (p<0.05). In particular, the light-curing mode exhibited a significantly higher bond strength than the co-curing one (p<0.05). The bond strength between the resin cement and dentin was improved in the 5-s drying groups than in the 10-s drying groups.

Resin-based composite materials are commonly used for restorations, but their dimensional changes during the polymerization could cause various clinical problems. This study evaluated the influence of a base of different materials and thicknesses on the stress magnitude and distribution in a second maxillary premolar with an MOD resin composite restoration using three-dimensional finite element analysis. A sound tooth without cavity was considered as the control group (ST), and another group was restored with composite resin without applying a base material in a MOD cavity (CR). The other three groups were restored with composite resin along with the following base materials: glass ionomer cement, low-viscosity resin, and tricalcium silicate, respectively (CR-GIC, CR-LR, and CR-TS). These three groups were further divided into two subgroups according to the thickness of the base layer: thin (0.5 mm) and thick (1.0 mm). The stress distribution was compared using the maximum principal stress after polymerization shrinkage and vertical loading with 600 N on the occlusal surface. Group ST showed the lowest stress value, and its stress propagation was confined to outer enamel surfaces only. Group CR demonstrated the highest stress distribution in the tooth-restoration interface with increased failure risk on marginal areas. The thin and thick subgroups of the three groups with a base layer had lower stress levels than Group CR. The base materials reduced the marginal stress caused by polymerization shrinkage of composite resin in MOD cavities. Different base materials and thicknesses did not affect the stress distribution.

Complicated crown fractures of maxillary anterior teeth caused by trauma in adolescence can cause functional and aesthetic problems.For crown fractures with pulp exposure, various restorative methods can be considered depending on the amount of remaining tooth structure.Direct resin restorations are the most traditional and effective method, but they are likely to discolor and break over time.Fixed prosthesis have a high possibility of re-restoration due to marginal disharmony due to tooth movement during the growth period, and restorations using post which are mainly performed for extensive crown fractures increase the risk of root perforation and root fracture.However, endocrown is an integrated structure that gains retention force from the pulp space, enabling effective reconstruction from a biomechanical perspective and providing advantages in restoring function and aesthetics.Therefore, endocrown can be considered as a restoration method for complicated crown fractures caused by trauma in adolescence.

Aim: The present study aimed to evaluate the intaglio surface trueness and fit of zirconia crowns depending on the different machining strategies used with the Cerec system. Materials and methods: Thirty duplicate tooth models for a single zirconia crown were randomly assigned to three groups (n = 10) according to the machining mode used for fabrication: grinding, wet milling, and dry milling. The scan data of the final crowns were compared with their design data to evaluate the intaglio surface trueness. The marginal and internal fit were evaluated using a cross-sectional method. The time required for the machining and sintering processes was measured for each group. Results: The wet -milling group showed better trueness (root mean square: 13.8 +/- 1.0 p.m) than the grinding and dry -milling groups (P<0.001). The marginal gap was greater in the grinding group (58.6 +/- 28.9 p.m) than that in the wet- and dry -milling groups (P < 0.001). The dry -milling group required the shortest time for the manufacturing process. Conclusion: All machining modes fabricated crowns with a clinically acceptable trueness and fit. However, the dry -milling mode was advantageous for the chairside CAD/CAM system with respect to time efficiency.

Background/purpose:Based on hydrodynamic theory, blocking the dentinal tubules can reduce discomfort caused by dentin hypersensitivity. This study identified the crystals formed in dentinal tubules from tricalcium silicate (TCS) in phosphate-buffered saline (PBS) and evaluated the effect of PBS concentration on crystal formation. Materials and methods:Sixty-nine specimens were made by isolating the cervical part of extracted premolars. TCS was applied by brushing for 10,000 strokes on dentin surface simulating sensitive dentin. Specimens were stored in PBS or solutions with concentrations 1/100, 1/10, 10, and 100 times that of PBS for 1, 30, 60, or 90 days (n = 3). Another nine specimens applied TCS, were immersed in PBS for 3 months, and divided into three subgroups: no treatment, sonication for 10 min, and 1M acetic acid treatment for 3 min. Crystal formation was examined using a scanning electron microscope, assigned five grade scores (0-4) according to maturation, and analyzed by a nonparametric two-way ANOVA (α = 0.05). Crystal components were analyzed using X-ray diffraction (XRD) and energy dispersion X-ray spectroscopy (EDS). Results:The maturation of intratubular crystals was dependent on time and PBS concentration (P < 0.05). In all periods, the high-concentration group showed a higher maturation grade than the low-concentration group. Intratubular crystals were similar to hydroxyapatite according to XRD and EDS, and they withstood sonication and acid application. Conclusion:TCS with nanosized particles formed hydroxyapatite-like crystals in the dentinal tubules, which were dependent on time and concentration of PBS and withstood sonication and acid application.

BACKGROUND:The accuracy of intraoral scanning is critical for computer-aided design/computer-aided manufacturing workflows in dentistry. However, data regarding the scanning accuracy of various adjacent restorative materials and intraoral scanners are lacking. This in vitro study aimed to evaluate the effect of adjacent restorative material type and CEREC's intraoral scanners on the accuracy of intraoral digital impressions for inlay cavities. METHODS:The artificial tooth was prepared with an occlusal cavity depth of 2 mm, a proximal box width at the gingival floor of 1.5 mm, and an equi-gingival margin extended disto-occlusally at the transition line angle on both the lingual and buccal sides for an inlay restoration. The adjacent teeth were veneered with crowns made of gold and zirconia, and an artificial tooth (resin) was utilized as the control group. The inlay cavity and adjacent teeth (Gold, Zirconia, and resin) were scanned 10 times using Chairside Economical Restoration of Esthetic Ceramics (CEREC) Primescan (PS), Omnicam (OC), and Bluecam (BC). A reference scan was obtained using a laboratory scanner (3-shape E3). Scanning was performed according to the manufacturer's instructions, including powder application for the BC group. Standard tesselation language files were analyzed using a three-dimensional analysis software program. Experimental data were analyzed using a two-way analysis of variance and the Tukey's post-hoc comparison test. RESULTS:The restorative materials of the adjacent teeth significantly affected the accuracy of the intraoral digital impressions (p < .05). The zirconia group exhibited the highest trueness deviation, followed by the resin and gold groups, with each demonstrating a statistically significant difference (p < .05). The resin group demonstrated the highest maximum positive deviation and deviation in precision. Gold exhibited the lowest average deviation value for trueness compared with those of the other adjacent restorative materials. Intraoral scanner type significantly influenced the trueness and precision of the scan data (p < .05). The average deviation of trueness according to the intraoral scanner type increased in the following order: BC > PS > OC. The average deviation in precision increased in the following order: PS>OC>BC (p < .05). CONCLUSION:The restorative materials of the adjacent tooth and the type of intraoral scanner affect the accuracy of the intraoral digital impression. The trueness of the digital images of the BC group, obtained by spraying the powder, was comparable to that of the PS group. Among the adjacent restorative materials, zirconia exhibited the lowest trueness. In contrast, PS demonstrated the highest precision among the intraoral scanners, while resin displayed the lowest precision among the adjacent restorative materials.

The images of the Quantitative Light induced Fluorescent (QLF) device, which provides both natural color images similar to those from intraoral cameras and fluorescent images using 405 nm light in a single shot, were evaluated for the validity and inter examiner reliability in detecting tooth cracks. QLF images of 26 cracked teeth before and after removing crack lines were taken. Two examiners assessed the QLF images before removing the crack line with natural color images, fluorescent images, and combination images showing both images simultaneously, and recorded the crack’s location after observing images. The reference standard of the crack’s location was established by a trained dentist based on QLF images after removing the crack line. The agreement between examiners and the reference standard of the crack line was calculated by kappa value. Inter examiner agreement of natural color images showed at 0.394, while fluorescent and combination images showed at 0.449 and 0.493. Compared with the reference standard, the combination and fluorescent images showed higher agreement at 0.742 and 0.662, while the natural color images showed the lowest agreement, at 0.164. Determining crack location using only natural colored QLF images is challenging, but fluorescent and combination images improved agreement between examiners and the reference standard.

A mesoporous bioactive glass nanoparticle (MBN) containing functional elements effectively enhances its healing effect in medical applications. The MBN mainly comprises SiO2 2 structure and controls the composition by incorporating functional ions into the glass network, which affects the network structure and bioactivity. Europium has already been identified to have luminescence properties for drug delivery systems and positively affects osteogenic properties. Therefore, in this study, we recognize the changes in the glass network according to different compositions with the same amount of europium oxide (10 mol%). The MBN compositions with SiO2-CaO-P2O5-Eu2O3 2 -CaO-P 2 O 5 -Eu 2 O 3 were synthesized by sol-gel method, and we control the contents of SiO2 2 and CaO, respectively. The obtained Eu-containing MBNs had spherical morphology with mesoporous structure. Changes in bioactivity and mineralization properties would be investigated to apply the dental products. After soaking in simulated body fluid (SBF), Eu-containing MBNs with substituted SiO2 2 form an amorphous calcium phosphate phase on their surface. The results indicate that incorporating Eu in the bioactive glass network is an effective strategy for mineralization and developing novel multifunctional MBNs for bone tissue and drug delivery carriers.

BACKGROUND:The accuracy of intraoral scanning plays a crucial role in the workflow of computer-assisted design/computer-assisted manufacturing. However, data regarding scanning accuracy for inlay preparation designs are lacking. The purpose of this in vitro study was to evaluate the influence of the depth of the occlusal cavity and width of the gingival floor of the proximal box on the trueness and precision of intraoral scans for inlay restoration. METHODS:Artificial teeth were used in this study. Four types of preparations for mesio-occlusal inlay were performed on each #36 artificial tooth depending on two different depths of the occlusal cavity (1 mm and 2 mm) and widths of the gingival floor of the proximal box (1.5 mm and 2.5 mm). Artificial teeth were scanned 10 times each with Cerec Primescan AC, and another scan was performed subsequently with a laboratory scanner as a reference (n = 10). Standard tessellation language files were analyzed using a three-dimensional analysis software program. Experimental data were analyzed using two-way analysis of variance and the Bonferroni multiple comparison test. RESULTS:The narrow shallow group had significantly higher deviation values for trueness than the wide deep group (p < 0.05). The wide deep group had the lowest average deviation value for trueness and there was no significant difference between the narrow deep and wide shallow groups (p > 0.05). For the mean maximum positive deviation, the wide groups had significantly lower values than the narrow groups (p < 0.05). Trueness was affected by both the width and depth(p < 0.05), whereas the mean maximum positive deviation was affected by the width (p < 0.05). The mean maximum negative deviation was affected by all three factors (p < 0.05). Precision was affected by the depth and the interaction between the depth of the occlusal cavity and width of the gingival floor (p < 0.05). CONCLUSIONS:The design of different inlay cavity configurations affected the accuracy of the digital intraoral scanner. The highest average deviation for trueness was observed in the narrow shallow group and the lowest in the wide deep group. With regard to precision, the narrow shallow group showed the lowest average deviation, and the narrow deep group showed highest value.

Abstract Background: During the cementation of indirect restorations, the conditions of the dentin surface and dentin adhesive's curing technique that affect the adhesion between dentin and an indirect restoration are essential issues for clinicians. This study investigates the effects of dentin's wetness, roughness, and curing modes of resin cement on bond strength when using universal adhesives for the cementation of indirect restorations. Methods: Forty human teeth were divided into eight groups according to three experimental factors: 1) dentin's roughness achieved by 250-or 600-grit Silicon-carbide (SiC) paper (coarse or fine), 2) dentin wetness with an air-drying time (5-s or 10-s), and 3) Single Bond Universal adhesive's curing mode by co-curing with RelyX Ultimate resin cement or light-curing separately after applying the adhesive(co-curing or light-curing). After resin discs were cemented with RelyX Ultimate, the microtensile bond strength (μTBS) was measured (n = 15 each). The failure mode and adhesive layers were observed using stereoscopic and confocal laser scanning microscopy (CLSM). Results: The roughness of the dentin surface did not significantly affect the bond strength (p > 0.05), and the curing mode of dentin adhesive and the 5-s drying group of dentin had significant effects on bond strength (p < 0.05). Light-curing groups and 5-s drying groups showed significantly higher bond strength than co-curing groups (p < 0.05), and 10-s drying groups (p < 0.05), respectively. Conclusions: When using Single Bond Universal adhesive and RelyX Ultimate resin cement, the light curing mode, in which the adhesive and resin cement is light-cured, showed higher bond strength than the co-curing mode. The bond strength between the resin cement and dentin was improved in the 5-s drying groups than in the 10-s drying groups.

Background/purpose: One of the challenges in adhesive ceramic restorations is deterioration of tooth-cement-ceramic interfaces. This study was to quantitatively investigate lipopolysaccharide (LPS) penetration through adhesive ceramic restorations.Materials and methods: Standardized holes were formed on ceramic (IPS Empress CAD, Ivoclar Vivadent) and human dentin discs. Prepared discs were randomly assigned to experimental groups (n Z 6/group): SC, self-adhesive resin cement (SmartCem 2, Dentsply Sirona) bonded to ceramic discs; ST, self-adhesive resin cement bonded to dentin discs; VC, etch-and-rinse resin cement (Variolink II, Ivoclar Vivadent AG) bonded to ceramic discs; VT, etch-and-rinse resin cement bonded to dentin discs. The specimens underwent thermocycling (10,000 cycles; 5-55 degrees C) then LPS penetration test until 5-weeks. A mixed effect analysis using R statistical language was performed for data analysis.Results: Dentin and ceramic bonded with etch-and-rinse resin cements (groups VT and VC) showed significantly less penetration than those with self-adhesive resin cement (groups ST and SC) (P < 0.05). ST showed significantly lower penetration than SC (P < 0.05), that showed similar penetration with positive control (P > 0.05). VC showed minimal penetration during observed time of period (P < 0.05). Scanning electron microscope observations showed different interfacial characteristics among the groups.

Omnichroma (OMN)는 최근에 소개된 구조색으로 색상을 나타내는 복합레진으로 와동을 둘러싼 치아 구조를 기반으로 색상을 표현한다. 본 연구의 목적은 다양한 와동의 깊이가 OMN의 색상 혼합 효과에 미치는 영향을 조사하는 것이다. 기존의 복합 레진(Filtek Z250 A2, A3, A4 색상)과 구조색 기반 복합레진(Omnichroma)을 사용하였다. 자체 제작한 실리콘 몰드(직경: 8 mm, 두께: 2, 3, 4 mm)를 사용하여 두 가지 유형의 시편을 준비하였다. 단일 시편(직경: 8 mm)은 Z250의 A2, A3, A4 색상 또는 OMN으로만 충전하여 각각 10개씩 만들었다. 이중 시편은 Z250의 A2, A3, A4 색상으로 직경 8mm의 디스크 형태의 시편을 만든 후 직경이 4 mm인 내부 와동을 1, 2, 3, 4 mm 깊이로 형성하여 OMN을 충전하였다. 이중 시편은 내부 와동의 두께당, 디스크 색상의 종류당 각각 10개씩의 시편을 제작하였다. 색상은 CIE (Commission Internationale d

Introduction: The aim of this case report was to discuss the clinical application using a quantitative light-induced fluorescent (QLF) device for the diagnosis and treatment of a cracked tooth as visualizing the tooth's crack. Case report: A 39-year-old woman visited a dental hospital complaining of throbbing pain on tooth #36. Observation of the tooth with naked eyes showed that tooth had a ceramic restoration with no specific findings. QLF device's images around the restoration, and after removal of the restoration were taken. In the QLF image after removal of the restoration, clear red-fluorescent crack line was shown, indicating that microorganism had penetrated along the crack path. During root canal treatment, the QLF image of the inside of the pulp chamber showed a pattern in which the crack line progressed into the tooth. During the treatment of the cracked tooth, the crack line was removed as much as possible using the fluorescent information obtained by the QLF device, and crack lines of fluorescence images quantitatively analyzed using a QLF's software. Conclusion: Images acquired with the QLF device can provide useful information for detecting crack lines, recording the treatment process, and restorative management of cracked teeth.