Assessment of Peri-implant Soft Tissue Adaptive Pressure and Time After Provisional Restorations.

Using interim restorations to remodel the peri-implant gingiva contour has been a common procedure in esthetic implant treatment. During the interim restoration delivery, the pressure between the restoration and gingiva typically causes ischemia. Adequate restoration should allow the tissue to recover from ischemia over a certain time. To assess the time needed for peri-implant soft tissue recovery, interim restorations were delivered on 25 single implant sites 2 weeks after stage-two surgery, and the gingiva appearance changes after delivery were recorded for 15 minutes using a video camera. Gingiva color changes along the time were measured and analyzed. The color differences between peri-implant mucosa at 10 min and 0 min, as well as between adjacent tooth gingiva, were all within a clinically acceptable range of color difference. The adaptive pressure technique by two-stage contouring exhibited an optimal peri-implant soft tissue profile within 10 minutes of the adaptive time.

The role of organic phosphate in the spatial control of periodontium complex bio-mineralization: an in vitro study.

The periodontal structure is a particularly exquisite model of hierarchical spatial control of mineralization. Extracellular matrix control in the selective mineralization of the periodontium complex remains elusive since the extracellular matrix is a set of mineralization promoters and inhibitors. The phosphorylated proteins, which are ubiquitous in the extracellular matrix of the periodontium complex, are well-documented as primary factors in the regulation of tissue mineralization. Whether organic phosphates are key regulators in defining the interfaces between dentin, cementum, periodontal ligament and alveolar bone is an issue worthy of research. Here, we investigated the in vitro remineralization process of demineralized and dephosphorylated periodontal tissue sections. When exposed to a metastable mineralization solution, a large number of calcospherulites deposited on the surface of the dephosphorylated sections and the tissue selective mineralization were disrupted. Interestingly, on adding a dentin matrix protein-1 analogue named polyacrylic acid, the surface mineralization rate in the dephosphorylated periodontal complex reduced dramatically. In contrast, hierarchical mineralization was displayed by the demineralized section at the tissue collagen fibrillar levels in both alveolar bone and dentin regions. These results demonstrated that the organic phosphate could prevent surface mineral deposition, and the minerals could penetrate the collagen fibrils to initiate a selective and hierarchal tissue mineralization with the assistance of the dentin matrix protein-1 analogue in the periodontal complex. This study enhances our understanding of the mineralization discrepancy in the periodontal tissues, which will provide some insight into the development of biomaterials for the regeneration of soft-hard tissue interfaces.

Comparison of Gingival Troughing by Laser and Retraction Cord.

This study was aimed at comparing the most common two methods for gingival troughing: presaturated cord and lasers (including diode, Nd:YAG, and Er:YAG). A total of 108 anterior teeth (58 maxillary and 50 mandibular) in 50 patients were included in this study. Gingival treatment was carried out in the following four groups: presaturated cord, diode laser, Nd:YAG laser, and Er:YAG laser. The gingival width and gingival recession (GR) were measured at different times (at the time of treatment, after 1 week, and after 4 weeks). The presaturated cord resulted in significantly higher (P < .05) GR than lasers and narrower gingival sulci. Er:YAG laser resulted in the quickest and most uneventful wound healing when compared to diode and Nd:YAG lasers.

Glycemic control and adipokines after periodontal therapy in patients with Type 2 diabetes and chronic periodontitis.

The mechanism by which chronic periodontitis (CP) affects type 2 diabetes (T2DM) remains unclear. Therefore, the aim of this study is to evaluate the effects of periodontal therapy (PT) on the glycemic control and adipokines of patients with T2DM and CP with the purpose of elucidating the possible mechanisms by which CP influences T2DM. Forty-four patients with T2DM and CP were randomly divided into two groups according to whether they underwent PT. Periodontal status, blood glucose, and the levels of serum tumor necrosis factor α (TNF-α), interleukin-6 (IL-6), adiponectin (APN), and fibroblast growth factor-21 (FGF-21) were measured at baseline and after 3 months. The results revealed that the probing depth (PD) and attachment loss (AL) were significantly improved, the serum levels of TNF-α and IL-6 were significantly decreased, and APN and FGF-21 exhibited substantial increases in the intervention group after 3 months (p < 0.05), whereas no significant changes were observed in the control group. The glycated hemoglobin (HbA1c) levels in both groups decreased significantly after 3 months compared with baseline (p < 0.05), but the intervention group exhibited a significantly greater change (p < 0.05). In conclusion, PT may relieve periodontal inflammation, which causes a reduction of insulin-antagonizing adipokines and an increase in insulin-sensitizing adipokines, thereby eliciting an improvement in glycemic control.

Glycemic control and adipokines after periodontal therapy in patients with Type 2 diabetes and chronic periodontitis

Abstract: The mechanism by which chronic periodontitis (CP) affects type 2 diabetes (T2DM) remains unclear. Therefore, the aim of this study is to evaluate the effects of periodontal therapy (PT) on the glycemic control and adipokines of patients with T2DM and CP with the purpose of elucidating the possible mechanisms by which CP influences T2DM. Forty-four patients with T2DM and CP were randomly divided into two groups according to whether they underwent PT. Periodontal status, blood glucose, and the levels of serum tumor necrosis factor α (TNF-α), interleukin-6 (IL-6), adiponectin (APN), and fibroblast growth factor-21 (FGF-21) were measured at baseline and after 3 months. The results revealed that the probing depth (PD) and attachment loss (AL) were significantly improved, the serum levels of TNF-α and IL-6 were significantly decreased, and APN and FGF-21 exhibited substantial increases in the intervention group after 3 months (p < 0.05), whereas no significant changes were observed in the control group. The glycated hemoglobin (HbA1c) levels in both groups decreased significantly after 3 months compared with baseline (p < 0.05), but the intervention group exhibited a significantly greater change (p < 0.05). In conclusion, PT may relieve periodontal inflammation, which causes a reduction of insulin-antagonizing adipokines and an increase in insulin-sensitizing adipokines, thereby eliciting an improvement in glycemic control.

The impact of Wnt signalling and hypoxia on osteogenic and cementogenic differentiation in human periodontal ligament cells.

Cementum is a periodontal support tissue that is directly connected to the periodontal ligament. It shares common traits with bone tissues, however, unlike bone, the cementum has a limited capacity for regeneration. As a result, following damage the cementum rarely, if ever, regenerates. Periodontal ligament cells (PDLCs) are able to differentiate into osteoblastic and cementogenic lineages according to specific local environmental conditions, including hypoxia, which is induced by inflammation or activation of the Wnt signalling pathway by local loading. The interactions between the Wnt signalling pathway and hypoxia during cementogenesis are of particular interest to improve the understanding of periodontal tissue regeneration. In the present study, osteogenic and cementogenic differentiation of PDLCs was investigated under hypoxic conditions in the presence and absence of Wnt pathway activation. Protein and gene expression of the osteogenic markers type 1 collagen (COL1) and runt­related transcription factor 2 (RUNX2), and cementum protein 1 (CEMP1) were used as markers for osteogenic and cementogenic differentiation, respectively. Wnt signalling activation inhibited cementogenesis, whereas hypoxia alone did not affect PDLC differentiation. However, hypoxia reversed the inhibition of cementogenesis that resulted from overexpression of Wnt signalling. Cross-talk between hypoxia and Wnt signalling pathways was, therefore, demonstrated to be involved in the differentiation of PDLCs to the osteogenic and cementogenic lineages. In summary, the present study suggests that the differentiation of PDLCs into osteogenic and cementogenic lineages is partially regulated by the Wnt signalling pathway and that hypoxia is also involved in this process.

Characterization of nano-structural and nano-mechanical properties of osteoarthritic subchondral bone.

BACKGROUND: Although articular cartilage is the primary tissues affected by osteoarthritis (OA), the underlying subchondral bone also undergoes noticeable changes. Despite the growing body of research into the biophysical and mechanical properties of OA bone there are few studies that have analysed the structure of the subchondral sclerosis at the nanoscale. In this study, the composition and nano-structural changes of human osteoarthritis (OA) subchondral bone were investigated to better understand the site-specific changes. METHODS: OA bone samples were collected from patients undergoing total knee replacement surgery and graded according to disease severity (grade I: mild OA; grade IV: severe OA). Transmission electron microscopy (TEM), Electron Diffraction, and Elemental Analysis techniques were used to explore the cross-banding pattern, nature of mineral phase and orientation of the crystal lattice. Subchondral bone nano-hydroxyapatite powders were prepared and characterised using high resolution transmission electron microscopy (HR-TEM) and fourier transform infrared spectroscopy (FTIR). Subchondal bone mechanical properties were investigated using a nano-indentation method. RESULTS: In grade I subchondral bone samples, a regular periodic fibril banding pattern was observed and the c-axis orientation of the apatite crystals was parallel to the long axis of the fibrils. By contrast, in grade IV OA bone samples, the bulk of fibrils formed a random and undulated arrangement accompanied by a circular oriented pattern of apatite crystals. Fibrils in grade IV bone showed non-hierarchical intra-fibrillar mineralization and higher calcium (Ca) to phosphorous (P) (Ca/P) ratios. Grade IV OA bone showed higher crystallinity of the mineral content, increased modulus and hardness compared with grade I OA bone. CONCLUSIONS: The findings from this study suggest that OA subchondral sclerotic bone has an altered mineralization process which results in nano-structural changes of apatite crystals that is likely to account for the compromised mechanical properties of OA subchondral bones.

Cloning and characterization of the human integrin ß6 gene promoter.

The integrin ß6 (ITGB6) gene, which encodes the limiting subunit of the integrin αvß6 heterodimer, plays an important role in wound healing and carcinogenesis. The mechanism underlying ITGB6 regulation, including the identification of DNA elements and cognate transcription factors responsible for basic transcription of human ITGB6 gene, remains unknown. This report describes the cloning and characterization of the human ITGB6 promoter. Using 5'-RACE (rapid amplification of cDNA ends) analysis, the transcriptional initiation site was identified. Promoter deletion analysis identified and functionally validated a TATA box located in the region -24 to -18 base pairs upstream of the ITGB6 promoter. The regulatory elements for transcription of the ITGB6 gene were predominantly located -289 to -150 from the ITGB6 promoter and contained putative binding sites for transcription factors such as STAT3 and C/EBPα. Using chromatin immunoprecipitation assays, this study has demonstrated, for the first time, that transcription factors STAT3 and C/EBPα are involved in the positive regulation of ITGB6 transcription in oral squamous cell carcinoma cells. These findings have important implications for unraveling the mechanism of abnormal ITGB6 activation in tissue remodeling and tumorigenesis.

Effectiveness of cysteine proteases on protein/pigment film removal.

OBJECTIVE: Theaflavin (TF) from the black tea can react to human salivary proline-rich proteins (PRPs) to form stains on exposed dental surfaces. Here, we employed a model of protein/pigment film using TF and dephosphorylated bovine ß-casein (Dß-CN), which has an extended conformation, similar to that of salivary PRPs, on a sensor surface to assess the efficacy of cysteine proteases (CPs) including papain, stem bromelain, and ficin, on removing TF bound to Dß-CN and the control TF readsorption on the residual substrate surfaces was also measured. METHODS: The protein/pigment complex film was built by using a quartz crystal microbalance with dissipation (QCM-D). The efficacies of CPs were assessed by Boltzman equation model. The surface details were detected by grazing angle infrared spectroscopy spectra, atomic force microscopy images, and contact angles. RESULTS: The efficacy order of CPs on hydrolyzing protein/pigment complex film is ficin>papain>bromelain. The results from grazing angle infrared spectroscopy spectra, atomic force microscopy images, and contact angles demonstrated that TF bound on the Dß-CN was effectively removed by the CPs, and the amount of TF readsorption on both the residual film of the Dß-CN/TF and the Dß-CN was markedly decreased after hydrolysis. CONCLUSION: This study indicates the potential application of the CPs for tooth stain removal and suggests that these enzymes are worthy of further investigation for use in oral healthcare.

The effect of various concentrations of papain on the properties and hydrolytic rates of ß-casein layers.

Recently, much attention has been focused on the investigation of the surface biocatalysis of proteases. In this study, papain, a proteolytic enzyme was used to hydrolyze a bovine ß-casein (ß-CN) layer, which was monitored by a quartz crystal microbalance with dissipation (QCM-D). The changes of the ß-CN layers before and after hydrolysis were characterized by atomic force microscopy (AFM) imaging, grazing angle infrared spectroscopy (GA-FTIR) spectra, and contact angle measurement. Our results demonstrated that the proteolytic reaction was enzyme concentration-dependent and started with the hydrophobic C-terminal sequence of the ß-CN. The remaining ß-CN layer became thinner, smoother, stiffer, and hydrophilic after hydrolysis. These results are conducive to the further understanding of the catalysis of papain on ß-CN layers in liquid-solid interfaces and the promotion of biocatalytic applications.

[The effects of firing numbers on the opening total pore volume, translucency parameter and color of dental all-ceramic systems].

OBJECTIVE: To evaluate the effects of firing numbers on the total opening pore volume (TPV), translucency parameter (TP) and color of dental all-ceramic systems. METHODS: Specimens of three kinds of all-ceramics systems were made, i.e. heat pressed all-ceramic (IPS Empress II), alumina all-ceramic (In-Cream alumina blanks) and zirconia all-ceramic (Cercon CAD/CAM zirconia). The specimens' TP, lightness (deltaL), chroma (deltaC) and TPV after 1, 3 and 5 firings were measured and calculated by spectrophotometer and surface area/porosity system. The data were analyzed statistically using SAS 8.0 software. RESULTS: There were significant differences in TPV, TP, deltaL and deltaC for all-ceramic specimens at same number of firings (P<0.05), i.e. IPS>alumina and zirconia for TPV (P<0.05); IPS>zirconia>alumina for TP and deltaL (P<0.05); IPS and alumina>zirconia for deltaC (P<0.05). The significant differences also presented in TPV, TP, deltaL and deltaC for a same specimen at different number of firings (P<0.05). With increasing number of firings, TPV decreased, and TP, deltaL and deltaC increased gradually. There were negative linear correlation between number of firings and TPV, TP, deltaL and deltaC (P<0.05). CONCLUSION: Repeated firings will affect TP and deltaL of all-ceramic restorations via the change of TPV.

[Studies on the saliva adsorption and the salivary film property on the hydroxyapatite surface].

OBJECTIVE: To evaluate the thickness and viscoelasticity of whole saliva (WS), parotid saliva (PS) and submandibular/sublingual gland saliva (SMSLS) film adsorption on the hydroxyapatite (HA) surface. METHODS: Ultra-thin layer of HA nanocrystals was coated on the dissipation TiO(2) sensor of gold quartz crystal microbalance using electrophoretic deposition technique. The thickness of the HA layer was measured by the ellipsometer, and element analysis was conducted using X-ray photoelectron spectroscopy. Atomic force microscopy and scanning electron microscope were used to observe its morphology. The in-situ adsorption thickness, the shear elastic modulus and the shear viscosity of salivary layers (WS, PS and SMSLS) on HA surfaces were investigated. The statistical data were analysed by an one-way ANOVA analysis followed by a SNK-q test. RESULTS: The results show that the HA layer was a plate-like morphology with 1.53 ± 0.12 in Ca/P molar ratio, (19.1 ± 0.9) nm in the thickness and (6.5 ± 1.6) nm in the roughness. The thickness of salivary film was SMSLS [(21.84 ± 1.25) nm] > WS[(17.91 ± 1.35) nm] > PS [(14.30 ± 1.03 nm) (P < 0.05). The shear elastic modulus of salivary film was PS [(0.61 ± 0.01) MPa] > SMSLS [(0.31 ± 0.09) MPa] and WS [(0.25 ± 0.03) MPa] (P < 0.05). The trend of the shear viscosity was opposite to one of thickness. CONCLUSIONS: The characteristics of saliva adsorption on HA surface suggest that the thicker, softer and more hydrated properties for the SMSLS and WS films are likely to afford a stronger lubrication to protect oral surfaces from wear and dehydration. The viscoelasticity of the PS film is probably related to the retention covering the oral cavity.

[Adsorption dynamics study on interactions of pigments and human whole saliva].

OBJECTIVE: In situ, real timely and dynamically monitoring the processes of theaflavin (TF), curcumin (Cur) and cyanidin (Cy) binding to human whole saliva (WS) surface has been investigated by surface plasmon resonance (SPR) technique at the molecular level. METHODS: The affinity between pigments and WS, association rate constant (k(a)), dissociation rate constant (k(d)), association equilibrium constant (K(A)) and dissociation equilibrium constant (K(D)) of pigments binding on WS surface had been determined by SPR and the Langmuir model as well as the Freundlich model. The data were analyzed by one-way ANOVA and SNK-q test. RESULTS: There were significant differences among TF, Cur and Cy in k(a), k(d), K(A) and K(D) (P<0.05). Our results showed that the adsorption isotherm of pigments on WS surface could be better described by the Freundlich model than the Langmuir model. The pigments adsorption on WS surface was dominant by specific interactions, such as hydrogen bonding. The affinity of pigments to WS were TF> Cur>Cy (P<0.05), as evidenced by the rate constants and equilibrium constants. CONCLUSION: Compared with Cur and Cy, TF shows much higher adsorption capacity on WS surface, suggesting the importance of the hydroxyl group in pigment/protein interactions.

Effect of various pH values, ionic strength, and temperature on papain hydrolysis of salivary film.

Stimulated human whole saliva (WS) was used to study the dynamics of papain hydrolysis at defined pH, ionic strength, and temperature with the view of reducing an acquired pellicle. A quartz crystal microbalance with dissipation (QCM-D) was used to monitor the changes in frequency caused by enzyme hydrolysis of WS films, and the hydrolytic parameters were calculated using an empirical model. The morphological and conformational changes of the salivary films before and after enzymatic hydrolysis were characterized by atomic force microscopy (AFM) imaging and grazing-angle Fourier transform infrared (GA-FTIR ) spectra, respectively. The characteristics of papain hydrolysis of WS films were pH-, ionic strength-, and temperature-dependent. The WS films were partially removed by the action of papain, resulting in thinner and smoother surfaces. The infrared data suggested that hydrolysis-induced deformation did not occur on the remnants of salivary films. The processes of papain hydrolysis of WS films can be controlled by properly regulating pH, ionic strength, and temperature.

[Adsorption kinetic study of the interaction between human salivary alpha-amylase and the polyphenoles from the black/green tea].

OBJECTIVE: To explore the driving force of the oral astringency produced by the interaction of theaflavin (TF) and epigallocatechin-3-gallate (EGCG) to human salivary a-amylase(HSA). METHODS: The constants of the rate, equilibrium of reaction (k(a), k(d), K(A), and K(D)) and Langmuir, Freundlich adsorption isotherm (K(L), K(f), and Mm) were determined by surface plasmon resonance (SPR) technique and adsorption kinetics. RESULTS: Both of Langmuir and Freundlich models could be used for describing the binding processes of TF and EGCG onto HSA surfaces, and there were no significant differences of the correlation coefficient of determination between these two models (P > 0.05). The constants of adsorption isotherm, the rate and equilibrium constants of the association for TF were higher than those of EGCG (P < 0.05). The rate and equilibrium constants of the dissociation for TF were lower than those of EGCG (P < 0.05). The affinity of TF to HSA was higher than that of EGCG. CONCLUSION: The sorely oral astringency is much easily produced by TF from the black tea rather than EGCG from the green tea. The driving force of the oral astringency is attributed to the hydrogen bonds of hydroxyl groups and hydrophobic interaction of galloyl groups in polyphenolic structures.

Affinity interactions between natural pigments and human whole saliva.

OBJECTIVE: The aim of the present study was to assess the null hypothesis that there are no differences of affinity between pigments and human whole saliva (WS), and the affinity is not influenced by the functional groups of pigments, temperatures, pH values, and salt concentrations. METHODS: The affinity constants of interactions between WS and theaflavin (TF)/curcumin (Cur)/cyanidin (Cy) were determined by surface plasmon resonance (SPR) and fluorescence quenching. Mass-uptake at various temperatures, pH values, and salt concentrations was also carried out. RESULTS: The order of affinity of the pigments binding to WS is TF>Cur>Cy. A large number of complexes and precipitations of pigments/proteins were formed through a quick, strong, and almost irreversible binding process. The mass-uptake of pigments was affected not only by the functional groups, but also by molecular weight of pigments, temperatures, pH values, and salt concentrations. CONCLUSION: The complex of pigments may easily and rapidly deposit onto the WS film, and are difficult to remove from the WS surface. However, the complex of pigments can be reduced by properly regulating the physicochemical conditions, such as temperatures, pH values, and salt concentrations.

[Influence of deposition time on chromatics during nitrogen-doped diamond like carbon coating on pure titanium].

OBJECTIVE: The aim of this study was to observed the influence of deposition time on chromatics during nitrogen-doped diamond like carbon coating (N-DLC) on pure titanium by multi impulse are plasma plating machine. METHODS: Applying multi impulse are plasma plating machine to produce TiN coatings on pure titanium in nitrogen atmosphere, then filming with nitrogen-doped DLC on TiN in methane (10-80 min in every 5 min). The colors of N-DLC were evaluated in the CIE1976 L*a*b* uniform color scale and Mussell notation. The surface morphology of every specimen was analyzed using scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). RESULTS: When changing the time of N-DLC coating deposition, N-DLC surface showed different color. Golden yellow was presented when deposition time was 30 min. SEM showed that crystallization was found in N-DLC coatings, the structure changed from stable to clutter by varying the deposition time. CONCLUSION: The chromatics of N-DLC coatings on pure titanium could get golden yellow when deposition time was 30 min, then the crystallized structure was stable.

The interactions of epigallocatechin-3-gallate with human whole saliva and parotid saliva.

OBJECTIVE: The aim of the present study was to assess the null hypothesis that the astringency and loss of lubrication in the oral cavity are not related to the properties of the epigallocatechin-3-gallate (EGCG) adlayer, the affinity and the entropy-drive of EGCG binding to saliva. METHODS: The mass, thickness, and viscoelasticity of the EGCG adlayer and the temperature dependence of EGCG adsorption onto saliva surfaces were determined by quartz crystal microbalance with dissipation (QCM-D). The affinities of EGCG to human whole saliva (WS) and to parotid saliva (PS) were carried out by QCM-D monitoring and fluorescence quenching. RESULTS: The stiffer and more compact EGCG adlayers were formed on saliva surfaces at various concentrations of EGCG. The affinity for EGCG binding to WS was higher than that to PS. The precipitation of EGCG/saliva was temperature-dependent. The driving force of EGCG binding to saliva is dominated by the hydrogen bond, the hydrophobic reaction, and the entropy-drive, which were confirmed by the FTIR spectra and the measurement of temperature- dependence, respectively. CONCLUSION: The viscoelasticity of the EGCG adlayer, the affinity of EGCG to saliva, and the priority of EGCG binding to hydrophobic proteins on the mucosa may account for the oral astringency and loss of lubrication.

[Study of nitrogen silicon zirconium-hydroxylapatite as a coating on pure titanium implantation].

OBJECTIVE: To compare the osseointegration and corrosion of different kind of coatings on pure titanium. METHODS: By plasma spraying technology, nitrogen silicon zirconium-hydroxylapatite (ZrSiN-HA) compound coating was prepared on the surface of pure titanium and the pure titanium was implanted with the mandible of the experimental animal. The superficial appearance of the compound coating was observed and analyzed by scanning electron microscope (SEM). The ZrSiN-HA, nitrogen silicon zirconium (ZrSiN), hydroxylapatite (HA) and pure titanium were compared and examined. In the four groups, the bone binding force of coatings were detected, and the superficial appearance of the break regions were observed by the electronic multipurpose material testing aircraft. In the four groups, the anticorrosive of coatings were compared and examined on the electrochemistry corrosion testing system. RESULTS: Experimental results indicated that the implant surface sprayed with the ZrSiN-HA was more compact than that sprayed with HA. The crystallization was obvious. Compared with the other coatings, the bone binding force of the ZrSiN-HA coating was the highest, and its anticorrosive performance was the strongest. CONCLUSION: The application of ZrSiN-HA coating is advantageous to the long-term retention of implant, and it has huge latent application value to dental dummy.

[Evaluation of three transmission parameters of dental opal porcelains and the correlations among parameters].

OBJECTIVE: To measure the translucency parameter (TP), masking effect (ME), and contrast ratio (CR) of opal porcelain of Ceramco, Shofu, Noritake, and Vita, and to compare the correlations among the three transmission parameters, in order to provide reference for selecting opal porcelain correctly. METHODS: The color of specimens was measured according to CIE L*a*b* under different background and reflectance mode with a Color-Eye 7000A spectrophotometer. The color difference, TP, and ME value were calculated. Within 400-750 nm spectra, the ratio of light reflectance was measured, and CR was also calculated. The data was compared by ANOVA and SNK-q test (alpha=0.05). The correlation and multiple linear regression between TP, CR, and ME were analyzed (alpha=0.05). RESULTS: There were statistical difference with different shade of the same brands (P<0.05). The correlations between ME and TP, TP and CR, ME and CR were existed (P<0.05). TP was correlated not only with ME but also with CR based on multiple regression analysis (P<0.05). The partial correlation coefficients were statistically significant (P<0.05). CR was the main devotion to translucency parameter on multiple regressions. CONCLUSION: It is recommended to select opal porcelains based on transmission parameters. CR value has an inner significance of opaque property of opal porcelain and can express opacity property of opal porcelain more appropriately than ME.