Scanning accuracy of an intraoral scanner according to different inlay preparation designs.

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.

Evaluation of the intaglio surface trueness and fit of zirconia crowns fabricated using different machining strategies with a chairside CAD/CAM system.

AIM: This 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 the 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 to their design data to evaluate the intaglio surface trueness. The marginal and internal fits were evaluated using the cross-sectional method. The time required for the machining and sintering processes was measured for each group. RESULT: The wet milling group showed better trueness (RMS, 13.8 ± 1.0 µm) than the grinding and dry milling groups (p < 0.001). The marginal gap was greater in the grinding group (58.6 ± 28.9 µm) than that in the wet milling 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.

In vivo real-time temperature measurement on the surface of intact and gold-restored teeth during consumption of hot and cold drinks.

This study aimed to measure real-time temperature changes in gold-restored teeth compared with intact teeth during the intake of hot and cold drinks. Sixteen molars, including eight natural intact teeth and eight restored teeth with gold inlays, were selected from the participants. Custom-made thermocouple sensors were attached to the coronal third of the buccal surface of teeth. Participants consecutively consumed hot and cold drinks according to a standardized regimen. Resting, maximum, and minimum temperatures; time to reach peak temperatures; and heating and cooling velocities were obtained. Statistical analysis was performed using independent two-sample t-test. Teeth with gold restorations showed a significantly higher maximum temperature (44.7 °C [SD 2.9]) than did natural teeth (40.5 °C [SD 1.2]) during hot water drinking and showed a lower minimum temperature (25.0 °C [SD 4.9]) than did natural teeth (31.5 °C [SD 3.1]) during cold water drinking. The heating and cooling rates for the teeth with gold restorations were two and three times higher than those of the natural teeth. Gold-restored teeth showed greater temperature change than intact teeth in terms of magnitude and velocity in response to temperature changes induced by hot and cold drinks.

Bactericidal effect on S. mutans using N-TiO2 with combined treatment of low concentration H2O2 and visible light.

PURPOSE: To test the feasibility of nitrogen-doped TiO2 nanoparticles in the killing of Streptococcus mutans (S. mutans) for short term treatment. METHODS: For the study, S. mutans were treated with the combinations of N-TiO2, visible light, and without/with 0.5% H2O2 inclusion. Visible light was irradiated for 3 minutes one time. RESULTS: Methylene blue solution was degraded (bleached) 5-30% by one of N-TiO2 (or TiO2) + visible laser (405 or 660 nm) +0.5% H2O2 conditions owing to almost linearly producing free radicals through photocatalysis. Antibacterial outcomes treated with N-TiO2 were slightly better than those by TiO2 regardless of test condition. Also, killing of S. mutans treated with 405 nm laser was slightly better than those by 660 nm laser. CLINICAL SIGNIFICANCE: S. mutans can be eliminated using N-TiO2 with clinically acceptable light (wavelength, intensity) and low concentration H2O2 condition under short term treatment.

Teeth whitening using nitrogen doped-TiO2 nanoparticles and hydrogen peroxide under visible light irradiation.

PURPOSE: To test the efficacy of nitrogen doped-TiO2 (N-TiO2) nanoparticles (NPs) on teeth whitening under visible light irradiation. METHODS: N-TiOV2 NPs were prepared by the sol-gel method, using TiN as a precursor. Their light absorbance and crystal structures were characterized. Photocatalytic reactions were tested using methylene blue (MB) and extracted teeth. For the extracted teeth, carbomer gel, without or with 3% H2O2, and light irradiated, with subsequent evaluation of the color differences. RESULTS: Unlike ordinary TiO2, N-TiO2 showed high absorbance after 400 nm. N-TiO2 prepared with TiN as a precursor showed rutile phase over the TiN structure. For MB solution, N-TiO2 with 3% H2O2 showed the maximum decrease in absorbance after laser irradiation. Observing the effect on teeth, N-TiO2+3% H2O2+405 nm laser treatment achieved approximately 25% higher whitening than that by 15% H2O2 during the same treatment time. Higher H2O2 concentrations may offer faster results. CLINICAL SIGNIFICANCE: N-TiO2 nanoparticles (without or with 3% H2O2) show better whitening of teeth as compared to 15% H2O2, if used with a visible laser for 5 hours. The potential on N-TiO2 nanoparticles to be used as a tooth whitener needs to be further explored to reduce its application time.

Autofluorescence spectra and image to differentiate restorative dental resins from the tooth.

PURPOSE: To compare the autofluorescence (AF) spectra of resin products with teeth to determine if this type of non-invasive testing is feasible for differentiating resin products from teeth during resin repair. METHODS: For the study, 11 methacrylate-based resin products were chosen. A 405 nm laser was used to induce AF, and a spectrophotometer and a qualitative laser-induced fluorescence (QLF) camera were used to obtain AF spectra and images, respectively. RESULTS: Resin products and teeth showed one or two emission peak(s) at 435-465 nm and 475-480 nm, respectively. Other resin constituents produced weak emission peaks beyond the 435-475 nm range. Resin products with high emission intensities produced bright images. When layered, surface resins (0.2 mm-thick) were different from underlying base resins and teeth. CLINICAL SIGNIFICANCE: During resin repair, a restored resin can be readily removed if AF spectroscopy is used alone or in combination with QLF imaging.

Evaluation of autofluorescence and image of oral pathogens and the tooth.

PURPOSE: To test the applicability of autofluorescence (AF) spectrum and image in the detection and identification of oral pathogens. METHODS: Oral pathogens (Candida albicans, Porphyromonas gingivalis, Streptococcus mutans) and teeth were used. To induce AF, the 405 nm laser was used as a light source, and AF was obtained and observed using a spectrometer, fluorescence camera, and microscope, respectively. RESULTS: The tested oral pathogens had similar spectral distributions, but their peak intensities and peak ratios were different. Their peak positions and spectral patterns were different from those of the tested sound and carious teeth. These differences were also found from the other referenced oral mucosa. Fluorescence image could localize the existence of oral bacteria. Oral pathogens could be imaged by fluorescence, but identification of each pathogen by image was not probable. CLINICAL SIGNIFICANCE: Oral pathogens can be observed and identified from the lesion if autofluorescence spectrum and fluorescence images are combined.

Influence of adjacent teeth on the accuracy of intraoral scanning systems for class II inlay preparation.

OBJECTIVE: This study aimed to evaluate the influence of the presence of adjacent teeth on the accuracy of intraoral scanning (IOS) systems for class II inlay preparation. MATERIALS AND METHODS: The mesio-occlusal inlay preparation was prepared in an anatomical model of the maxillary molar. The prepared tooth was secured to a typodont with the mesial adjacent tooth removed or in situ. Ten digital impressions of the inlay preparation were acquired using three IOS systems (CEREC Primescan, 3Shape TRIOS 3, and Medit i500). A laboratory scanner (3Shape E3) was used to obtain the reference scan data. The mean absolute deviation values were calculated to evaluate the accuracy of the digital models. RESULTS: The group with the adjacent teeth present showed lower trueness and precision compared to that without the adjacent tooth (p < .05). Significant differences were observed among the IOS systems (p < .05). Primescan showed the highest accuracy, irrespective of the presence of adjacent teeth. CONCLUSIONS: The presence of the adjacent tooth negatively affected the accuracy of all the IOSs tested. Although the performance of Primescan was superior to that of TRIOS 3 and i500, each IOS system showed clinically acceptable levels of accuracy for class II inlay preparation. CLINICAL SIGNIFICANCE: The adjacent tooth can be a confounding factor for accurate digital impressions of class II inlay preparation.

Influence of different inlay configurations and distance from the adjacent tooth on the accuracy of an intraoral scan.

STATEMENT OF PROBLEM: Clinical guidelines for obtaining accurate scan data during the intraoral scanning of inlay cavities with various configurations and interproximal distances are lacking. PURPOSE: The purpose of this in vitro study was to evaluate the effect of interproximal distance and cavity type on the accuracy of digital scans for inlay cavities, including proximal cavities. MATERIAL AND METHODS: Four artificial teeth with 4 types of inlay cavities designed based on the buccolingual width and gingival level of the proximal box were installed in a mannequin at distances of 0.6, 0.8, and 1.0 mm from the adjacent teeth. Reference scans of the 4 artificial teeth were obtained by using a laboratory scanner. The CEREC Primescan AC was used to acquire digital scan data (each n=10). Standard tessellation language (STL) files were analyzed with a 3-dimensional analysis software program. The mean deviation values were measured with a 3-dimensional best-fit alignment method to evaluate the accuracy of the digital scan data. Statistical analyses were performed by using 2-way ANOVA and the Bonferroni multiple comparison test (α=.05). RESULTS: As per the interproximal distance, the 1.0-mm group showed significantly higher trueness than the 0.6-mm group (P<.05). As the interproximal distance increased, the maximum positive deviation significantly decreased (P<.05). Maximum negative deviation and precision of the scan data were not significantly different among the distance groups (P>.05). Cavity type had a significant influence on the trueness and precision of the scan data (P<.05). In particular, the narrow long cavity type had an adverse effect on the precision and maximum positive deviation of scan data. CONCLUSIONS: During the intraoral scanning of class II inlay restoration, interproximal distance and cavity type affected the accuracy of an intraoral scan. As the interproximal distance increased, the trueness of the acquired digital images increased and the maximum positive deviation significantly decreased. The narrow long cavity type negatively affected the mean maximum positive deviation and precision of scan data.

Endodontic retreatment of a calcified anterior tooth using a 3D-printed endodontic guide.

The treatment of teeth with severely calcified canals is a difficult procedure for clinicians. Procedural accidents such as drill path deviation or perforation of the root canal often occur. 3D-printed directional guides made using CBCT and CAD/CAM can help the clinician to accurately drill in the original root canal direction. Furthermore, chairside operating times and excessive loss of tooth structure are reduced, and the risk of perforation is avoided. The present case report describes two cases of calcified root canals with path deviations that were retreated utilizing a guided endodontic technique.

Difference assessment of composite resins and sound tooth applicable in the resin-imbedded tooth for resin repair using fluorescence, microhardness, DIAGNOdent, and X-ray image.

OBJECTIVE: Visual differentiation of resin and tooth in a tooth cavity is not simple due to their highly similar shade. The purpose of the present study was to find any noninvasive method which can effectively differentiate resin from sound tooth in a resin-imbedded tooth for resin repair. MATERIALS AND METHODS: For the study, various resin products were imbedded into the cavity of sound tooth. By applying laser of different wavelengths, autofluorescence (AF) of sound tooth and resin products were obtained. Microhardness, X-ray radiograph, and DIAGNOdent were tested for each tooth, resin product, and resin-imbedded tooth. RESULTS: For the AF spectra obtained using the 405-nm wavelength, sound tooth has emission peak at 440-470 nm and near 490 nm. Sound tooth has several times higher microhardness than resin products regardless of position in tooth subsurface. Due to the difference of radiopaque fillers' composition and concentration, resin products have different brightness in the X-ray radiograph. DIAGNOdent readings for tooth and resin products were inconsistently different, and the difference of obtained values was slightly not to be applicable for the differentiation. CONCLUSION: Among the tested methods, with noninvasive treatment, AF spectrum by the 405-nm wavelength showed the apparent difference between resin and tooth. CLINICAL SIGNIFICANCE: For the resin repair in a resin-imbedded tooth cavity, AF spectrum produced by 405-nm wavelength could be a useful method in tracing the resin-tooth boundary if combined with conventional X-ray radiography.

How light attenuation and filler content affect the microhardness and polymerization shrinkage and translucency of bulk-fill composites?

OBJECTIVES: The purpose of this study was to investigate the microhardness, polymerization shrinkage, and translucency of bulk-fill composites (BFCs) which have different light attenuation properties and filler contents. MATERIALS AND METHODS: Five BFCs [Filtek Bulk Fill (FB), SureFil SDR (SS), Venus Bulk Fill (VB), SonicFill (SF), and Tetric N-Ceram Bulk Fill (TB)] and two resin-based composites (RBCs) [Tetric N-Ceram (TN) and Filtek Z350XT Flowable (ZF)] were chosen. Numbers of transmitted photons, refractive index, microhardness at different thicknesses, polymerization shrinkage, and translucency parameter (TP) were evaluated. RESULTS: Attenuation coefficients (ACs) based on measured photons ranged from -0.88 to -1.90. BFCs, except SF, had lower AC values than TN or ZF, and BFCs, except TN, had smaller refractive index decreases between top and bottom surfaces. Regardless of an exponential decrease in photon counts, microhardness decreased linearly as specimen thickens. Moreover, microhardness of BFCs showed smaller top-to-bottom decreases (11.5-48.8 %) than TN or ZF (57.3 and 71.5 %, respectively). BFCs with low filler contents showed lower microhardness and higher polymerization shrinkage than those of high filler contents. Also, BFCs had significantly higher (p < 0.001) TP values than TN or ZF. CONCLUSION: BFCs attenuated light less than RBCs. However, some BFCs had much lower top surface microhardness and higher polymerization shrinkage than tested RBCs. CLINICAL RELEVANCE: Despite the convenience of bulk filling, careful selection of BFC is advised because some BFCs have worse microhardness and polymerization shrinkage than RBCs due to their lower filler contents.

Effect of two lasers on the polymerization of composite resins: single vs combination.

The selection of a light-curing unit for the curing composite resins is important to achieve best outcomes. The purpose of the present study was to test lasers of 457 and 473 nm alone or in combination under different light conditions with respect to the cure of composite resins. Four different composite resins were light cured using five different laser combinations (530 mW/cm(2) 457 nm only, 530 mW/cm(2) 473 nm only, 177 mW/cm(2) 457 + 177 mW/cm(2) 473 nm, 265 mW/cm(2) 457 + 265 mW/cm(2) 473 nm, and 354 mW/cm(2) 457 + 354 mW/cm(2) 473 nm). Microhardness and polymerization shrinkage were evaluated. A light-emitting diode (LED) unit was used for comparison purposes. On top surfaces, after aging for 24 h, microhardness achieved using the LED unit and the lasers with different conditions ranged 42.4-65.5 and 38.9-67.7 Hv, respectively, and on bottom surfaces, corresponding ranges were 25.2-56.1 and 18.5-55.7 Hv, respectively. Of the conditions used, 354 mW/cm(2) 457 nm + 354 mW/cm(2) 473 nm produced the highest bottom microhardness (33.8-55.6 Hv). On top and bottom surfaces, microhardness by the lowest total light intensity, 354 (177 × 2) mW/cm(2), ranged 39.0-60.5 and 18.5-52.8 Hv, respectively. Generally, 530 mW/cm(2) at 457 nm produced the lowest polymerization shrinkage. However, shrinkage values obtained using all five laser conditions were similar. The study shows the lasers of 457 and 473 nm are useful for curing composite resins alone or in combination at much lower light intensities than the LED unit.

Effect of dentin surface conditions and curing mode of resin cement on the dentin bond strength.

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.

Comparison of the stress distribution in base materials and thicknesses in composite resin restorations.

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.

Effect of a DPSS laser on the shear bond strength of ceramic brackets with different base designs.

This study evaluated the shear bond strength (SBS) and adhesive remnant index (ARI) of ceramic brackets with different base designs using a 473-nm diode-pumped solid-state (DPSS) laser to test its usefulness as a light source. A total of 180 caries-free human premolars were divided into four groups according to the base designs: microcrystalline, crystalline particle (CP), dovetail, and mesh. For each base design, teeth were divided into three different subgroups for light curing using three different light-curing units (LCUs) (quartz-tungsten-halogen unit, light-emitting diode unit, and a DPSS laser of 473 nm). Applied light intensities for the DPSS laser and the other LCUs were approximately 630 and 900 mW/cm(2), respectively. Stainless steel brackets with a mesh design served as controls. The failure modes of debonded brackets were scored using ARI. As a result, brackets bonded using the DPSS laser had the highest SBS values (16.5-27.3 MPa) among the LCUs regardless of base design. Regarding base designs, the CP groups showed the highest SBS values (22.9-27.3 MPa) regardless of LCU. Furthermore, stainless steel brackets with a mesh design had the lowest SBS values regardless of LCU. In many cases, brackets bonded using the DPSS laser had higher ARI scores and had more adhesive on their bases than on tooth surfaces. The study shows that the 473-nm DPSS laser has considerable potential for bonding ceramic brackets at lower light intensities than the other light-curing units examined.

Mechanical properties of composite resins light-cured using a blue DPSS laser.

Lasers have many favorable features as a light source owing to their monochromaticity and coherence. This study examined the mechanical properties of composite resins that were light-cured using a diode-pumped solid state (DPSS) laser. Eight composite resins were light-cured using four different light sources (one quartz-tungsten-halogen (QTH), two light-emitting diodes (LEDs), and one DPSS laser with a wavelength of 473 nm). The light intensity of the DPSS laser and remaining light-curing units were approximately 500 and 900 mW/cm(2), respectively. The microhardness, flexural properties, and compressive properties were evaluated using the Vickers hardness test, three-point bending test, and compression test, respectively. In most cases, the microhardness, flexural properties, and compressive properties of the specimens light-cured using the DPSS laser were similar to those obtained using the other light-curing units. Within the limits of the study, the microhardness, flexural modulus, and compressive strength were linearly correlated with the filler content (in weight percent). The flexural modulus and compressive modulus were also linearly correlated with the microhardness. Even with a much lower light intensity, the DPSS laser with a wavelength of 473 nm can polymerize composite resins and give comparable mechanical properties to those obtained using the other light-curing units.

Incidence of three roots and/or four root canals in the permanent mandibular first molars in a Korean sub-population.

OBJECTIVES: The purpose of this study was to evaluate the prevalence of three-rooted permanent mandibular first molars (PMFMs) with four canals and their morphological characteristics among a Korean population from using cone-beam computed tomography scans (CBCTs). MATERIALS AND METHODS: Among the 705 CBCTs screened, 472 patient cases possessing at least one PMFM were identified. A total of 780 PMFMs were evaluated in axial section series to determine the number of roots and canals. The incidences of three-rooted PMFMs were compared with regard to gender and location. For distal root(s) with two canals, inter-orifice distances (IOD) between distobuccal and distolingual canals were measured at pulpal floor and furcation levels. The difference of IOD between males and females was also analyzed using chi-square tests. RESULTS: Among the 472 CBCTs of 225 females and 247 males, 84 females and 107 males were found to have at least one three-rooted PMFM. Among the 780 PMFMs, 191 PMFMs (24.5%, 89 of 397 left and 102 of 383 right) were found to have three roots. The prevalence of distal root(s) with two canals was 34.2% (267 of 780). From the molars with two distal canals, the mean IOD between distobuccal and distolingual canals at the pulpal floor level was 3.1 mm in males and 2.9 mm in females (p = 0.0428). CONCLUSIONS: The occurrence of three-rooted PMFMs among a Korean population was 24.5% and was higher than other countries and ethnicities. Understanding the prevalence of PMFMs with a distolingual root and/or canal in a Korean population and the IOD between distobuccal and distolingual canals may be useful for successful endodontic treatments. CLINICAL RELEVANCE: Acknowledgment of potential incidence of three-rooted permanent mandibular first molars with four canals and the distance between two distal canals may increase the success rate of root canal treatment by reducing the missing canal untreated.

Clinical applications of a quantitative light-induced fluorescent (QLF) device in the detection and management of cracked teeth: A case report.

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.

Lipopolysaccharide penetration analysis of two different resin cement systems to dentin and ceramic surface.

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 = 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 °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. Conclusion: Within the limitation of this study, etch-and-rinse resin cement showed less LPS penetration than self-adhesive resin cement on both ceramic and dentin surfaces.