Effect of Photo-Fenton Bleaching on Tetracycline-stained Dentin in vitro

Effect of Staining Beverages on Color Stability of Composite: A Spectrophotometric Study

Objective

This study used spectrophotometry to examine how staining beverages affect the color stability of three commercial composite materials (nanohybrid composite (A), bulk fill composite (B), and flowable composite (C)) over time.

Materials and Methods

Composite discs were randomly divided into groups. The specimens were kept in coffee, tea, red wine, and cola for 14 days at 37°C in the dark. At baseline, 7 days, and 14 days, spectrophotometers measured color. Calculated and analyzed color differences (E).

Results

Staining beverages changed the color of all composites. Composite material A had the best color stability, whereas material C stained beverages the most. Red wine and coffee discolored composites most. Discoloration increased over the 14-day immersion period.

Conclusion

Composite materials with better color stability were material A. Red wine and coffee discolored composites most. When choosing restorative materials, dentists should consider composite materials' color stability for long-lasting, visually acceptable results.

A critical analysis of research methods and experimental models to study tooth discolouration from endodontic materials

As a range of materials used in endodontics may cause tooth discolouration, exploration of factors responsible for the darkening of the tooth crown or root is warranted. This narrative review paper discusses the range of technical factors that apply in laboratory studies that assess endodontic discolouration. As an example of how these factors operate, particular examples relating to discolouration caused by endodontic medicaments containing tetracycline antibiotics are used. Following the PRILE 2021 guidelines approach, a summary of key variables to be addressed in the methodology for laboratory studies is presented, to inform future work.

Comparison of Commercial Calcium Hydroxide Pastes for Prolonged Antibacterial Effect using a Colourimetric Assessment

The anti-microbial activity of calcium hydroxide pastes used in endodontics is dependent on establishing high levels of hydroxyl ions in dentine. This study investigated hydroxyl ion diffusion from different commercial calcium hydroxide pastes using a novel colourimetric method. In this method, human tooth roots were stained with anthocyanin dye, which changed their colour according to the local pH conditions. Prepared root canals were filled with pastes formulated with the vehicle of water (Pulpdent™, Calasept Plus™), polyethylene glycol (PEG) (Calmix™) or a mixture of water, PEG and ibuprofen (Odontocide™). The changes in dye colour at fixed distances from the canal wall were monitored using standardised digital photography over a period of 3 weeks. A repeated measures analysis tracked changes in each root from baseline. Release of hydroxyl ions varied between the different commercial compositions containing water or PEG as solvents. The colour changes in the dentine, due to released hydroxyl ions, were greatest and more prolonged for completely non-aqueous compositions, when using PEG 400 as the vehicle. When water was present in the product, the duration of the pH changes was shorter. This was attributed to the presence of hydroxyl ions in the water (the common-ion effect) and a more vigorous buffering of hydroxyl ions by dentine proteins.