Visualization of the pulp chamber roof and residual dentin thickness by spectral-domain optical coherence tomography in vitro

A concept to detect a subgingival finish line using an intraoral optical coherence tomography system: A clinical report

This clinical report introduces an approach for detecting the supragingival finish line by penetrating the teeth and gingival tissue using optical coherence tomography (OCT) technology. This approach was used in 3 patients who underwent tooth preparation with a subgingival finish line. Consequently, the subgingival finish line, typically challenging to discern clearly in intraoral scans, was identifiable in the OCT image.

Dental diagnosis for inlay restoration using an intraoral optical coherence tomography system: A case report

PATIENTS

The patient was a 32-year-old man who underwent amalgam restoration of the mandibular right second molar. An amalgam restoration fracture was diagnosed by intraoral optical coherence tomography (OCT), and pulp exposure was examined during cavity preparation. Subsequently, a definitive ceramic restoration was fabricated, and the marginal fit in the oral cavity was evaluated using the OCT system.

DISCUSSION

The existing OCT system cannot acquire images inside the oral cavity because of the large probe size. However, the proposed intraoral OCT system can access the prostheses in the mandibular right second molar. Therefore, dental diagnosis for restoration treatment with dental prosthesis fracture, marginal gap, and pulp exposure after tooth preparation is possible using the proposed intraoral OCT system.

CONCLUSIONS

The use of the intraoral OCT system improved dental diagnosis by allowing the dentist to confirm quantitative values through cross-sectional images, rather than that by determining a treatment plan after visual dental diagnosis.

The Effect of LncRNA H19 on Human Dental Pulp Cells Through Tumor Growth Factor-β1 (TGF-β1)/Smad Signaling Pathway

The pulp tissue is located in the pulp cavity of tooth and has the ability of nutrition, feeling, and defense. Human dental pulp cells (hDPCs) are the main cells of pulp with the ability to self-renew and multi-directional differentiation. LncRNA H19 is involved in the regulation of human dental pulp stem cells, but the specific mechanism has not been elucidated. hDPCs were isolated and cultured in vitro to measure vimentin expression by immunohistochemistry (IHC). hDPCs were randomly assigned into control group, negative control (NC) group and lncRNA H19 overexpression group followed by measuring lncRNA H19, DSPP, and DMP-1 mRNA expression, cell proliferation, ALP activity, BMP-2 expression by ELISA, TGF-β1, Smad2, and Smad4 expression by Western blot. hDPCs were positive for vimentin staining and confirmed to be derived from mesenchymal. Transfection of pcDNA3.1-LncRNA H19 plasmid significantly increased LncRNA H19 expression, promoted cell proliferation, enhanced ALP activity, upregulated DSPP and DMP-1, elevated BMP-2 expression in cell supernatant, as well as promoted TGF-β1, Smad2, and Smad4 expressions compared with control (P < 0.05). In conclusion, lncRNA H19 facilitates hDPCs differentiation into odontoblasts by promoting cell proliferation and increasing BMP-2 secretion via regulating TGF-β1/Smad signaling pathway.

Quantitative label-free optical technique to analyze the ultrastructure changes and spatiotemporal relationship of enamel induced by Msx2 deletion

New advances in the molecular mechanism of enamel mineralization reveal the practical significance of regenerative medicine in clinical transformation. Muscle segment homeobox 2 (MSX2), a transcription factor, is recently reported to be closely associated with the amelogenesis imperfecta (AI). To elucidate the biomineralization framework of AI enamel, herein, Msx2 gene mutant mice are investigated by dual-mode noninvasive spectroscopic analytical techniques for the first time. Optical coherence tomography (OCT) records the depth-resolved structural information of mice teeth, where a dramatic decrease in enamel thickness and quality occurred in Msx2 deficient (Msx2^-/- ) enamel. And it has the advantages of fast, noninvasive and low cost. Raman spectroscopy, a powerful molecular fingerprint tool, further witnesses an imbalance of inorganic and organic contents in Msx2^-/- enamel. In addition, abnormal expression of MSX2 also influences the spatial distribution of phosphate in enamel according to the Raman spectral imaging. Therefore, OCT integrated with Raman spectroscopy provides the quantitative label-free optical parameters of both the physical structure and chemical component in mice enamel, which strengthens the understanding of the biomineralization process underlying the Msx2-related amelogenesis imperfect.

Optical coherence tomography's current clinical medical and dental applications: a review

Optical coherence tomography (OCT) is a non-invasive investigative technique that is used to obtain high-resolution three-dimensional (3D) images of biological structures. This method is useful in diagnosing diseases of specific organs like the eye, where a direct biopsy cannot be conducted. Since its inception, significant advancements have been made in its technology. Apart from its initial application in ophthalmology for retinal imaging, substantial technological innovations in OCT brought by the research community have enabled its utilization beyond its original scope and allowed its application in many new clinical areas. This review presents a summary of the clinical applications of OCT in the field of medicine (ophthalmology, cardiology, otology, and dermatology) and dentistry (tissue imaging, detection of caries, analysis of dental polymer composite restorations, imaging of root canals, and diagnosis of oral cancer). In addition, potential advantages and disadvantages of OCT are also discussed.

Handheld optical coherence tomography for clinical assessment of dental plaque and gingiva

SIGNIFICANCE

Optical coherence tomography (OCT) offers high spatial resolution and contrast for imaging intraoral structures, yet few studies have investigated its clinical feasibility for dental plaque and gingiva imaging in vivo. Furthermore, the accessibility is often limited to anterior teeth due to bulky imaging systems and probes.

AIM

A custom-designed, handheld probe-based, spectral-domain OCT system with an interchangeable attachment was developed to assess dental plaque and gingival health in a clinical setting.

APPROACH

Healthy volunteers and subjects with gingivitis and sufficient plaque were recruited. The handheld OCT system was operated by trained dental hygienists to acquire images of dental plaque and gingiva at various locations and after one-week use of oral hygiene products.

RESULTS

The handheld OCT can access premolars, first molars, and lingual sides of teeth to visualize the plaque distribution. OCT intensity-based texture analysis revealed lower intensity from selected sites in subjects with gingivitis. The distribution of the dental plaque after one-week use of the oral hygiene products was compared, showing the capability of OCT as a longitudinal tracking tool.

CONCLUSIONS

OCT has a strong potential to display and assess dental plaque and gingiva in a clinical setting. Meanwhile, technological challenges remain to perform systematic longitudinal tracking and comparative analyses.