Fluorescence spectrometry based chromaticity mapping, characterization, and quantitative assessment of dental caries.

PURPOSE: Dental caries detection, especially the accurate detection of early caries, facilitates prompt interventions. It is reasonably common to use fluorescence imaging for classification and evaluation of caries, but lacks a quantitative, precise and easy-to-use characterization for practical applications. In this study a quantitative approach for caries stage detection by correlating caries spectral and chromatic features was examined. METHODS: A 405 nm LED light source was used as the excitation source. A hyperspectral imaging camera is employed to collect 336 spectral data of different caries stages. Four critical intervals for different stages of caries were extracted by fluorescence spectral features. The mapping relationship between caries spectral and chromatic features was established by Fast Formula Fitting (FFF) and Neural Network Fitting (NNF) methods. RESULTS: The 470-780 nm spectral power distribution was proved to be the best matching color waveband guiding the selection of filters in future instrument development. The correlation coefficients for the two fitting methods were 0.990 and 0.999, respectively. Both methods achieved caries stage prediction at the pixel level with high accuracy using color information. The visualization region in the chromaticity diagram was created. CONCLUSIONS: This quantitative method enables accurate prediction of caries on the entire tooth surface and facilitates the development of portable and low-cost caries detection instruments.

Human amniotic mesenchymal stem cells combined with PPCNg facilitate injured endometrial regeneration.

BACKGROUND: Caused by the injury to the endometrial basal layer, intrauterine adhesions (IUA) are characterized by uterine cavity obliteration, leading to impaired fertility. Human amniotic mesenchymal stem cells (hAMSCs) have the potential to promote endometrial regeneration mainly through paracrine ability. PPCNg is a thermoresponsive biomaterial consisted of Poly (polyethylene glycol citrate-co-N-isopropylacrylamide) (PPCN) mixed with gelatin, which has been reported as a scaffold for stem cell transplantation. This study aims to investigate the therapeutic effect of hAMSCs combined with PPCNg transplantation in promoting the regeneration of injured endometrium. METHODS: hAMSCs were cultured in different concentrates of PPCNg in vitro, and their proliferation, apoptosis and cell cycle were examined by CCK-8 assay and flow cytometry. Immunofluorescence was used to determine the MSCs specific surface markers. The expression of pluripotent genes was analyzed by qRT-PCR. The multiple-lineage differentiation potential was further evaluated by detecting the differentiation-related genes using qRT-PCR and specific staining. The Sprague-Dawley (SD) rat IUA model was established with 95% ethanol. hAMSCs combined with PPCNg were transplanted through intrauterine injection. The retention of DiR-labeled hAMSCs was observed by vivo fluorescence imaging. The endometrium morphology was assessed using hematoxylin and eosin (H&E) and Masson staining. Immunohistochemistry staining was performed to detect biomarkers related to endometrial proliferation, re-epithelialization, angiogenesis and endometrial receptivity. The function of regenerated endometrium was evaluated by pregnancy tests. RESULTS: hAMSCs maintained normal cell proliferation, apoptosis and cell cycle in PPCNg. Immunofluorescence and qRT-PCR showed that hAMSCs cultured in PPCNg and hAMSCs cultured alone expressed the same surface markers and pluripotent genes. hAMSCs exhibited normal multilineage differentiation potential in PPCNg. Vivo fluorescence imaging results revealed that the fluorescence intensity of hAMSCs combined with PPCNg intrauterine transplantation was stronger than that of direct hAMSCs intrauterine transplantation. Histological assays showed the increase in the thickness of endometrial and the number of endometrial glands, and the remarkably decrease in the fibrosis area in the PPCNg/hAMSCs group. The expressions of Ki-67, CK7, CK19, VEGF, ER and PR were significantly increased in the PPCNg/hAMSCs group. Moreover, the number of implanted embryos and pregnancy rate were significantly higher in the PPCNg/hAMSCs group than in the hAMSCs group. CONCLUSIONS: PPCNg is suitable for growth, phenotype maintenance and multilineage differentiation of hAMSCs. hAMSCs combined with PPCNg intrauterine transplantation can facilitate the regeneration of injured endometrium by improving utilization rates of hAMSCs, and eventually restore reproductive capacity.

Management of intrauterine adhesions using human amniotic mesenchymal stromal cells to promote endometrial regeneration and repair through Notch signalling.

Intrauterine adhesions (IUAs) severely hamper women's reproductive functions. Human amniotic mesenchymal stromal cell (hAMSC) transplantation is effective in treating IUAs. Here, we examined the function of Notch signalling in IUA treatment with hAMSC transplantation. Forty-five Sprague-Dawley female rats were randomly divided into the sham operation, IUA, IUA + E2, IUA + hAMSCs and IUA + hAMSCs + E2 groups. After IUA induction in the rats, hAMSCs promoted endometrial regeneration and repair via differentiation into endometrial epithelial cells. In all groups, the expression of key proteins in Notch signalling was detected in the uterus by immunohistochemistry. The results indicated Notch signalling activation in the hAMSCs and hAMSCs + E2 groups. We could also induce hAMSC differentiation to generate endometrial epithelial cells in vitro. Furthermore, the inhibition of Notch signalling using the AdR-dnNotch1 vector suppressed hAMSC differentiation (assessed by epithelial and mesenchymal marker levels), whereas its activation using the AdR-Jagged1 vector increased differentiation. The above findings indicate Notch signalling mediates the differentiation of hAMSCs into endometrial epithelial cells, thus promoting endometrial regeneration and repair; Notch signalling could have an important function in IUA treatment.

The effect of implant shape and screw pitch on microdamage in mandibular bone.

PURPOSE: The aim of this study was to investigate the effect of implant shape and screw pitch on microdamage in bone during insertion of dental implants. MATERIALS AND METHODS: Thirty custom-made implants (length, 10 mm; diameters, 4.1 mm; cylindrical, tapered, and taper-cylindrical shapes; screw pitches, 1.25 and 0.8 mm; classified as 1.25C, 0.8C, 1.25T, 0.8T, 1.25TC, 0.8TC) were placed with a surgical device in the mandibles of eight goats. Two implant sites were prepared in the edentulous area on each side of the mandible. Implants were placed in a randomized order. Immediately after placement of the implants, the bone blocks with the implants were collected, bulk stained with basic fuchsin, embedded in methyl methacrylate, and sectioned. Histomorphometric quantification of the microcrack length (Cr.Le, µm); microcrack surface density (Cr.Le/B.Ar, µm/mm(2) ), and damaged bone area fraction (DB.Ar/B.Ar, %) were measured. RESULTS: The Cr.Le, Cr.Le/B.Ar, and DB.Ar/B.Ar values of 0.8TC group were 80.96 ± 17.55, 478.75 ± 51.85, and 4.40 ± 0.36, respectively. All these parameters of microdamage induced by 0.8TC were significantly lower than those induced by other five types of implants (p < .05). CONCLUSION: Taper-cylindrical implants with 0.8 mm screw pitch caused the least microdamage to the bone in comparison with the other five types of implants during placement of implants.

Smoking, radiotherapy, diabetes and osteoporosis as risk factors for dental implant failure: a meta-analysis.

BACKGROUND: There are conflicting reports as to the association between smoking, radiotherapy, diabetes and osteoporosis and the risk of dental implant failure. We undertook a meta-analysis to evaluate the association between smoking, radiotherapy, diabetes and osteoporosis and the risk of dental implant failure. METHODS: A comprehensive research on MEDLINE and EMBASE, up to January 2013, was conducted to identify potential studies. References of relevant studies were also searched. Screening, data extraction and quality assessment were conducted independently and in duplicate. A random-effects meta-analysis was used to pool estimates of relative risks (RRs) with 95% confidence intervals (CIs). RESULTS: A total of 51 studies were identified in this meta-analysis, with more than 40,000 dental implants placed under risk-threatening conditions. The pooled RRs showed a direct association between smoking (n = 33; RR = 1.92; 95% CI, 1.67-2.21) and radiotherapy (n = 16; RR = 2.28; 95% CI, 1.49-3.51) and the risk of dental implant failure, whereas no inverse impact of diabetes (n = 5; RR = 0.90; 95% CI, 0.62-1.32) on the risk of dental implant failure was found. The influence of osteoporosis on the risk of dental implant failure was direct but not significant (n = 4; RR = 1.09; 95% CI, 0.79-1.52). The subgroup analysis indicated no influence of study design, geographical location, length of follow-up, sample size, or mean age of recruited patients. CONCLUSIONS: Smoking and radiotherapy were associated with an increased risk of dental implant failure. The relationship between diabetes and osteoporosis and the risk of implant failure warrant further study.

A comparative study of dog models for osteotome sinus floor elevation and dental implants in posterior maxilla subjacent to the maxillary sinus.

OBJECTIVE: The objective of this study was to investigate the suitability of beagles and Labrador retrievers as animal models for osteotome sinus floor elevation (OSFE) and dental implants in posterior maxilla subjacent to sinus. STUDY DESIGN: Ten beagles and 8 Labrador retrievers were included. Their posterior maxillas subjacent to the sinus were studied by a gross survey, CT scan, and histologic analysis. RESULTS: In the posterior maxilla subjacent to sinus, the bone height was significantly higher for Labrador retrievers than for beagles (P < .05). There was no significant difference in sinus size from the coronal section and its location from the sagittal section (P > .05) between Labrador retrievers and beagles. CONCLUSIONS: As an animal model, the Labrador is more suitable for OSFE and dental implants in posterior maxilla subjacent to sinus. The midpoint of the maxillary fourth premolar is an ideal site for implantation.