Efficacy of bisphosphonates in detection of early enamel caries using NIR fluorescence imaging and inhibition of caries progression.

NIR fluorescence imaging using bisphosphonate-Indocyanine green has been indicated for early interproximal caries detection. This study assessed diagnostic accuracy of caries detection by NIR fluorescence imaging with OsteoSense 750® (OS750) in vitro and ex vivo, and to analyze the therapeutic efficacy of a bisphosphonate (Etidronate) in inhibiting enamel caries progression in vitro. Methods: Four experiments were conducted using extracted human teeth; 1) to calculate the infiltration rate of OS750 into interproximal white spot lesions using fluorescence microscope, 2) to assess diagnostic accuracy of interproximal natural white spot lesions using desktop NIR fluorescence imaging device in vitro setting, 3) to assess diagnostic accuracy of artificially created deeper enamel carious lesion (0.5 mm~1.0 mm) using NIR fluorescence image through the head-mount display in ex vivo setting, 4) to compare the progression on the enamel caries lesions treated by Etidronate, NaF and distilled-water. Diagnostic accuracy was analyzed using sensitivity, specificity and receiver operating curves (ROC). The caries progression was calculated with micro-CT and was statistically analyzed using a two-way ANOVA and the Tukey HDS post-hoc test. Results: 1) The infiltration rate of OS750 was 101.83% ± 8.66 (Min: 90.10%, Max: 133.94%). 2) The average of sensitivity and specificity in vitro setting experiments were 86.7% ± 4.4% and 70% ± 11%, respectively. The average of area under the ROC curves (AUC) was 0.883 ± 0.059 indicating excellent performance. 3) The mean sensitivity and specificity in ex vivo setting was 82.97% ± 15% and 76.78% ± 13.27% respectively. 4) The carious lesion volume treated by Etidronate was significantly smaller at post treatment-1 (p<0.05) and treatment-2 (p<0.01) than the control. There was no significant difference in lesion volume in the Etidronate and NaF group at the time point of post treatment-1. Conclusion: This study suggests that bisphosphonates contribute to both early diagnosis of enamel caries and inhibition of caries progression.

Endogenous acid ceramidase protects epithelial cells from Porphyromonas gingivalis-induced inflammation in vitro.

Ceramidases are a group of enzymes that degrade pro-inflammatory ceramide by cleaving a fatty acid to form anti-inflammatory sphingosine lipid. Thus far, acid, neutral and alkaline ceramidase isozymes have been described. However, the expression patterns of ceramidase isoforms as well as their role in periodontal disease pathogenesis remain unknown. In this study, expression patterns of ceramidase isoforms were quantified by real-time PCR and immunohistochemistry in gingival samples of patients with periodontitis and healthy subjects, as well as in EpiGingivalTM-3D culture and OBA-9 gingival epithelial cells both of which were stimulated with or without the presence of live Porphyromonas gingivalis (ATCC 33277 strain). A significantly lower level of acid ceramidase expression was detected in gingival tissues from periodontal patients compared to those from healthy subjects. In addition, acid-ceramidase expression in EpiGingival™ 3D culture and OBA-9 cells was suppressed by stimulation with P. gingivalis in vitro. No significant fluctuation was detected for neutral or alkaline ceramidases in either gingival samples or cell cultures. Next, to elucidate the role of acid ceramidase in P. gingivalis-induced inflammation in vitro, OBA-9 cells were transduced with adenoviral vector expressing the human acid ceramidase (Ad-ASAH1) gene or control adenoviral vector (Ad-control). In response to stimulation with P. gingivalis, ASAH1-over-expressing OBA-9 cells showed significantly lower mRNA expressions of caspase-3 as well as the percentage of Annexin V-positive cells, when compared with OBA-9 cells transduced with Ad-control vector. Furthermore, in response to stimulation with P. gingivalis, ASAH1-over-expressing OBA-9 cells produced less TNF-α, IL-6, and IL1ß pro-inflammatory cytokines than observed in OBA-9 cells transduced with Ad-control vector. Collectively, our data show the novel discovery of anti-inflammatory and anti-apoptotic effects of acid ceramidase in host cells exposed to periodontal bacteria, and the attenuation of the expression of host-protective acid ceramidase in periodontal lesions.

A prospective clinical trial to assess the optical efficacy of pink neck implants and pink abutments on soft tissue esthetics.

OBJECTIVE: The purpose of this prospective, randomized, controlled, multicenter clinical study was to analyze the optical effects of an anodized pink colored implant shoulder/abutment system in the peri-implant mucosa of immediately placed dental implants. MATERIALS AND METHOD: Forty subjects with a restoratively hopeless tooth in the maxillary esthetic zone, were recruited and randomized to receive either a pink-neck implant, or a conventional gray implant. All patients received an immediate implant and immediate provisional and two identical CAD/CAM titanium abutments with different surface colors: pink and gray, and one zirconia all-ceramic crown. The color of the peri-implant mucosa was measured using a dental spectrophotometer and analyzed using CIELAB color system. RESULTS: The overall color difference between the peri-implant mucosa with a pink abutment and a gray abutment was ΔE = 4.22. Patients with gray implants presented a color change of ΔE = 3.86-4.17 with this abutment change, while patients with pink implants had a color change of ΔE = 3.84-4.69. The peri-implant mucosa with a pink abutment was significantly more red when compared with a gray abutment (P ≤ .01). CONCLUSIONS: When a pink abutment was used, there is a significant color change of the peri-implant mucosa that is above the detectable color threshold. CLINICAL SIGNIFICANCE: Esthetic outcomes are important for the success of implant treatment of maxillary anterior implants. The phenomenon of the gray color of a dental implant and abutment shining through the peri-implant mucosa has been documented in the literature. The objective of this study was to assess the optical effect of an anodized pink-neck implant and a pink abutment on the color of peri-implant mucosa. This study demonstrates that using pink-neck implant and a pink abutment would contribute positively to the overall esthetic outcome for an anterior implant.

Identification of putative bone anabolic peptides targeting adherent plasma membrane.

Bone matrix provides unknown essential cues for osteoblast lineage cells to develop, grow, repair and remodel bones via adherent plasma membrane. Because of its tight sealing with bone matrix in vivo and culture surface in vitro as well, the adherent plasma membrane has been unveiled target of investigation to date. Herein, we report a new approach to explore the adherence plasma membrane of osteoblasts with biofunctional peptide candidates in a bacterial peptide library. To accomplish this, human osteoblast like hFOB 1.19 cells were cultured on porous filter with 8 µm pore through which bacterial peptides were allowed to meet the membrane for affinity selection. The affinity-selected peptides were coated on culture plate to further evaluate their influence on osteoblastic cell adhesion, as well as expressions of osteoblast differentiation markers, alkaline phosphatase and osteocalcin. Finally, the serial screenings identified two prominent active peptides that enhanced the differentiation markers nearly to the same level as a control peptide of bone morphogenetic protein-2. Osteogenic activity is expected for the peptides when immobilized on bone implant surface.

Assessing the accuracy of computer color matching with a new dental porcelain shade system.

STATEMENT OF PROBLEM: In a previous study, a novel computer color matching system for dental ceramic restoration was developed, and 21 new shades were established. Theoretically, a natural tooth color can be accurately reproduced by combining 2 or 3 ceramic mixtures from the database of 21 new shades. PURPOSE: The purpose of this study was to test the use of these shades in conjunction with the computer color matching system to determine their ability to accurately reproduce the body color of 29 shade tabs from a shade guide (VITAPAN 3D-Master). MATERIAL AND METHODS: Disks of 21 reference shades were prepared with porcelain (Cerabien CZR) and polished to 1.0 mm thickness. A spectrophotometer was used to measure the reflectance values from 380 to 780 nm for each disk; the scattering coefficient and absorption coefficient were determined. By using the reflectance values and the scattering and absorption coefficients, the computer color matching program generated porcelain prescriptions incorporating proportions from the 21 reference shades to reproduce the shade tabs. Disks were fabricated from the prescriptions, polished to 1.0 mm thickness, then placed over a zirconia core plate and measured with the spectrophotometer. The color differences (ΔE*) between the shade tabs and the corresponding ceramic disks were calculated. Statistical analysis was performed with the 1-sample t test. RESULTS: The ΔE* values between computer color matching specimens and the target shade tabs varied from 0.5 to 1.9, with an average ΔE* of 1.3, which was significantly less than the clinically detectable ΔE* threshold of 1.6 (P<.001). CONCLUSIONS: The computer color matching system with the established 21 new shades is accurate and effective for reproducing tooth shades.

Color effects of gingiva on cervical regions of all-ceramic crowns.

STATEMENT OF PROBLEM: The final color of all-ceramic crowns is influenced by the color of both the remaining tooth structure and the surrounding gingival tissue. The optical effects of gingival tissue on an all-ceramic crown have never been fully studied. PURPOSE: The purpose of this study is to investigate the effects of gingival color on ceramic crowns in the cervical region. materials and methods: Thirty-one all-ceramic crowns of differing shades were included in this study. Using a spectrophotometer, the color values of each crown were measured on a typodont in the absence of an artificial gingiva (control group) and in the presence of an artificial gingiva (test group). CIELAB color coordinates (L*, a*, b*) were collected from three regions of the cervical area in descending order from the gingival margin (upper region, middle region, and lower region). Color difference values (ΔE*) were calculated for each cervical region between the test and control groups. ΔE* between the test and control groups from the upper to lower cervical regions was also compared with each other. The statistical analysis was performed using the student t-test and one-way analysis of variance (ANOVA) test. RESULTS: The mean ΔE* values between the test group and control group at the upper, middle, and lower cervical regions were 5.8, 2.8, and 1.8, respectively. Significant color differences between the test and control group were detected in all three incremental regions (p < 0.001 at ΔE* = 1.6 threshold), with all color coordinates (L*, a*, and b*) contributing significantly to the color differences in these regions (p < 0.001). The color variations in the cervical area also varied significantly from the upper region to the lower region, with L* and a* contributing most to the differences. CONCLUSIONS: The presence of artificial gingiva is a critical factor in precise color matching and color reproduction for all-ceramic crowns. CLINICAL SIGNIFICANCE: Gingival tissue has significant optical effects on the color of all-ceramic crowns at the cervical areas; therefore, it is suggested that artificial gingiva be used by both dentists and ceramists while matching and replicating tooth color with ceramic restorations. (J Esthet Restor Dent ••:••-••, 2012).

Comparison of Peri-implant Soft Tissue Color with the Use of Pink-Neck vs Gray Implants and Abutments Based on Soft Tissue Thickness: A 6-Month Follow-up Study.

PURPOSE: To compare the optical effects of an immediately placed anodized pink-neck implant and abutment vs a conventional gray implant and abutment in relation to soft tissue thickness 6 months after the restoration was completed. MATERIALS AND METHODS: Forty patients with a hopeless maxillary anterior tooth received an immediate implant and an immediate provisional or custom healing abutment after flapless extraction. Participants were randomized to receive either a conventional titanium implant (control) or a pink-neck implant (test). All patients then received two identical CAD/CAM titanium abutments (one conventional gray, delivered first, and one anodized to appear pink, delivered 3 weeks after) and a zirconia crown. A spectrophotometer was used to record the color of the peri-implant mucosa and gingiva 3 weeks after delivery of each abutment and 6 months after the final restoration was delivered. The color difference between the two sites was calculated (ΔL*, Δa*, Δb*), and correlations with soft tissue thickness, change in ridge dimension, and implant position were assessed. RESULTS: Irrespective of the randomization group, changing the abutments from gray to pink showed a change in color between the peri-implant mucosa and the natural gingiva. Patients with a thin gingival biotype showed a statistically significant color change (P = .00089) in the a* axis, meaning that the gingiva appeared more pink (Δa*). No significant correlation between the soft tissue color and buccolingual collapse, vertical recession, or implant position was observed in either group. CONCLUSION: The difference in color observed between the peri-implant mucosa and the gingiva was considerable in all groups. Anodized pink implants and abutments could reduce the difference in the red aspect (Δa*) of the peri-implant mucosa compared to the adjacent gingiva in patients with a thin biotype.

Changes of the alveolar ridge dimension and gingival recession associated with implant position and tissue phenotype with immediate implant placement: A randomised controlled clinical trial.

PURPOSE: This prospective, randomised, controlled clinical trial evaluated the relationship between alveolar ridge dimensional change and recession with the implant position (horizontal and vertical) and tissue phenotype in immediately placed and provisionalised implants without the use of bone grafting. MATERIALS AND METHODS: Patients (n = 40) with a hopeless maxillary anterior tooth received an immediate implant and immediate provisional or customised healing abutment after flapless extraction. Implants were finally restored 3 months after placement and followed up for 6 months after delivery of the restoration. The alveolar ridge dimensional change and recession were measured using cone beam computed tomography (CBCT) scans and digitalised dental casts. Alveolar contour changes were correlated to implant position and tissue phenotype. RESULTS: The tissue phenotype showed no significant correlation to the alveolar ridge dimensional change. At 6 months, the average alveolar ridge dimensional change was approximately 0.7 mm in the buccolingual dimension independent of tissue phenotype. A statistically significant difference was observed on the recession values comparing tissue phenotypes, with more recession observed in the thin phenotype (1.96 mm) than in the thick phenotype (1.18 mm). A significant correlation was observed between horizontal implant position and buccolingual alveolar ridge change. A positive correlation was observed between the horizontal implant position and the dimensional change measured in the casts at the level of the free gingival margin. A statistically significant negative correlation was observed between the horizontal implant position and the resorption measured by the CBCT scans. CONCLUSIONS: Patients with thin tissue phenotype had a more marked recession. The horizontal implant position showed a relationship to the alveolar ridge dimensional changes observed. The greater the buccal gap distance between the implant and the buccal plate, the lesser the radiographic changes observed in the alveolar bone, however, the greater the changes observed in the buccal aspect of the casts at the level of the free gingival margin.

Comparison of the Color Appearance of Peri-implant Soft Tissue with Natural Gingiva Using Anodized Pink-Neck Implants and Pink Abutments: A Prospective Clinical Trial.

PURPOSE: The aim of this study was to assess the visual effects of pink-neck implants and pink abutments with respect to the color of natural gingiva. The distribution pattern and magnitude of CIELAB color difference coordinates were studied. MATERIALS AND METHODS: Forty subjects with a tooth in the maxillary esthetic zone deemed hopeless were recruited. Patients were randomized to either a conventional gray implant or a pink-neck implant. The hopeless tooth was removed and patients received an immediate implant along with an immediate customized provisional prosthesis. The provisional was maintained for 3 months to allow for complete healing of the implants. Two identical CAD/CAM titanium abutments only differing in color (gray and pink) were fabricated along with an all-ceramic zirconia crown. The gray abutment was delivered first with a zirconia crown, and it was replaced with the pink abutment 3 weeks later. Three weeks after insertion of each abutment with the zirconia crown, a spectrophotometer was used to collect the color of the peri-implant mucosa and natural gingiva, so the difference between the two sites could be calculated (ΔL* [difference in lightness], Δa* [difference in green-red axis], Δb* [difference in blue-yellow axis]). The natural gingiva measured was the gingiva of a contralateral or adjacent unrestored tooth. The effect of implant color and abutment on the color difference between peri-implant mucosa and natural gingiva was investigated with a linear regression model using a generalized estimating equation (GEE) approach. RESULTS: Raw data demonstrated statistically insignificant smaller ΔL*, Δa*, Δb* between peri-implant soft tissue and natural gingiva when the implant was pink versus gray. Further, there were statistically insignificant smaller ΔL* and Δb* between peri-implant soft tissue and natural gingiva when the abutment was pink versus gray. Δa* between peri-implant soft tissue and natural gingiva was significantly smaller when using a pink abutment regardless of the implant type (P < .05). CONCLUSION: Using an anodized pink abutment and/or a pink-neck implant minimizes the color difference observed between the peri-implant mucosa and the natural gingiva in the redness spectrum. These advances in technology assist in helping the peri-implant mucosa appear more natural by minimizing the color variance.

The feasibility of using coronally advanced flap with an extracellular matrix membrane for treating gingival recession defects: a preclinical study.

The guided tissue regeneration (GTR) procedure has been demonstrated to successfully correct gingival recession (GR) defects. The aim of this study was to assess the feasibility of using the combination of a coronally advanced flap (CAF) with an extracellular membrane (ECM) to correct GR. GR defects were induced in the maxillary posterior region in five baboons. A 3-month healing period followed before the ECM was placed over the defect and covered with a CAF. Probing depth (PD), recession depth (RD), recession width (RW), and keratinized tissue width (KTW) were measured at baseline and 3 months postoperatively. Block biopsies of the treated areas were submitted for histologic review after a healing period of 3 months. There were no significant differences between the test (ECM + CAF) and control (CAF) groups in terms of changes in PD, RD, RW, and KTW after 3 months of treatment. However, significant differences have been noted for preoperation and postsurgery RD and RW values for both the control and test groups. Histomorphometric results showed minimal alveolar bone and connective tissue replacing the ECM membrane. CAF (either with or without the use of an ECM) is effective for the treatment of GR defects.

Optical effects of different colors of artificial gingiva on ceramic crowns.

OBJECTIVES: The interaction between gingival color and the shade of ceramic restorations has never been fully studied. The purpose of this study is to investigate the optical effects of altering artificial gingival color on the ceramic crown shade in the cervical area. METHODS: Thirty-one all-ceramic crowns of different shades were used in this study with six different artificial gingival colors. Using a spectrophotometer (Crystaleye(®) Olympus, Japan), we measured the shade of crowns in cervical areas with each of six different artificial gingiva. The crown color measured in the presence of pink artificial gingiva (control) was compared with the crown color with five other artificial gingiva. color difference values ΔE* were calculated and compared between the control group and test groups and the correlation of the artificial gingival color with the crown color was also assessed. RESULTS: Significant differences were found in the mean L* and a* values of all-ceramic crowns at the cervical regions in all six gingival color groups (p<0.001) and significant Pearson correlations were also found for the mean L* (r=0.987, p<0.001) and a* (r=0.856, p=0.03) values between the artificial gingiva and the ceramic crowns. The mean ΔE* values between the control group and each of the five other gingival groups were all significantly larger than the clinical perceptual threshold of ΔE* 1.6 (p<0.001). CONCLUSIONS: Different colors of artificial gingiva generated clinically detectable shade differences in the cervical region of ceramic crowns.

Assessment of a prototype computer colour matching system to reproduce natural tooth colour on ceramic restorations.

OBJECTIVES: The aim of this study was to assess the accuracy of a prototype computer colour matching (CCM) system for dental ceramics targeting the colour of natural maxillary central incisors employing a dental spectrophotometer and the Kubelka-Munk theory. METHODS: Seventeen human volunteers with natural intact maxillary central incisors were selected to participate in this study. One central incisor from each subject was measured in the body region by a spectrophotometer and the reflectance values were used by the CCM system in order to generate a prescription for a ceramic mixture to reproduce the target tooth's colour. Ceramic discs were fabricated based on these prescriptions and layered on a zirconia ceramic core material of a specified colour. The colour match of each two-layered specimen to the target natural tooth was assessed by CIELAB colour coordinates (ΔE(*), ΔL(*), Δa(*) and Δb(*)). RESULTS: The average colour difference ΔE(*) value was 2.58±84 for the ceramic specimen-natural tooth (CS-NT) pairs. ΔL(*) values ranged from 0.17 to 2.71, Δa(*) values ranged from -1.70 to 0.61, and Δb(*) values ranged from -1.48 to 3.81. There was a moderate inverse correlation (R=-0.44, p-value=0.0721) between L(*) values for natural target teeth and ΔE(*) values; no such correlation was found for a(*) and b(*) values. CONCLUSION: The newly developed prototype CCM system has the potential to be used as an efficient tool in the reproduction of natural tooth colour.