Colorimetric evaluation of white spot lesions following external bleaching with fluoridation: An in-vitro study

Nano-hydroxyapatite-induced remineralization of artificial white spot lesions after bleaching treatment with 10% carbamide peroxide

OBJECTIVE

To assessed in vitro the effect of nanohydroxyapatite (n-HA) to improve the aesthetic appearance and microhardness of white spot lesions (WSL) when associated with a low-concentration bleaching agent (carbamide peroxide-CP10%).

MATERIAL AND METHODS

Enamel/dentin specimens (n = 60) of 5 × 5 × 2.2 mm were prepared, of these, 48 were submitted to pH-cycling to create artificial WSL. Subsequently, these were allocated into five groups (n = 12): n-HA; n-HA + CP10%; CP10%; WSL control (WSL_C ); sound control (Sound). The color was assessed at baseline, pre-treatment, and post-treatment using a spectrophotometer, and the color (ΔE/ΔE₀₀ ) and whiteness index (ΔWID) alterations were determined. The enamel cross-sectional microhardness (CSMH) was evaluated (post-treatment) with a Knoop indenter, 25gf/5 s, 20-200 μm. The data was analyzed through generalized linear models (α = 5%).

RESULTS

ΔE and ΔE₀₀ were significantly higher for the bleached groups (n-HA + CP10% and CP10%), and the n-HA was higher than the WSL_C group (p < 0.05). ΔWID was significantly higher for the bleached groups (p < 0.05). The CSMH values were significantly higher in the sound group than in the n-HA, CP10%, and WSL_C groups (p < 0.05). The WSL_C had lower microhardness than the n-HA + CP10% and sound groups (p < 0.05).

CONCLUSION

n-HA is suitable to remineralize and recover the color of the WSL. However, its association with CP10% maintains the esthetical outcome while increasing its in-depth remineralizing effect.

CLINICAL SIGNIFICANCE

Considering the aesthetic and functional repercussions of the WSL persistence, treatments that tend to improve its physical appearance and reinforce its weakened substructure in a non-invasive way are ideal. For this associating low-concentration, bleaching agents to the remineralizing treatments is promising to treat this type of lesions.

Pathophysiology of Demineralization, Part II: Enamel White Spots, Cavitated Caries, and Bone Infection

PURPOSE OF REVIEW

Compare noninfectious (part I) to infectious (part II) demineralization of bones and teeth. Evaluate similarities and differences in the expression of hard tissue degradation for the two most common chronic demineralization diseases: osteoporosis and dental caries.

RECENT FINDINGS

The physiology of demineralization is similar for the sterile skeleton compared to the septic dentition. Superimposing the pathologic variable of infection reveals a unique pathophysiology for dental caries. Mineralized tissues are compromised by microdamage, demineralization, and infection. Osseous tissues remodel (turnover) to maintain structural integrity, but the heavily loaded dentition does not turnover so it is ultimately at risk of collapse. A carious tooth is a potential vector for periapical infection that may be life-threatening. Insipient caries is initiated as a subsurface decalcification in enamel that is not detectable until a depth of ~400μm when it becomes visible as a white spot. Reliable detection and remineralization of invisible caries would advance cost-effective wellness worldwide.

Relationship between orthodontic treatment and dental caries: results from a national survey

OBJECTIVES

Orthodontic treatment has been suggested to increase the risk of dental caries. The aim of this study was to evaluate the association between orthodontic treatment and the likelihood of dental caries.

METHODS

The study included data for adults aged ≥ 19 years who participated in the Korea National Health and Nutrition Examination Survey in 2013-2015. The participants' demographic, socio-economic, and general and oral health-care data were collected by trained interviewers using a structured questionnaire. The number of decayed teeth (DT) and the decayed, missing and filled teeth (DMFT) index score on oral examinations performed by dentists were compared between subjects who underwent orthodontic treatment and those who did not, using the chi-squared test and logistic regression analysis.

RESULTS

All logistic regression analysis models showed a significant association between orthodontic treatment and untreated dental caries. The likelihood of having untreated dental caries was lower in subjects who had received orthodontic treatment than in those who had not, regardless of confounding factors (P < 0.001). After adjustment for confounding factors, the mean number of DT was lower in subjects who had received orthodontic treatment than in those who had not (0.66 vs. 0.94; P < 0.001). There was no statistically significant difference in the DMFT index score between the two groups.

CONCLUSIONS

Orthodontic treatment was associated with a decreased likelihood of untreated dental caries. Moreover, there was no evidence indicating a link between the DMFT index score and orthodontic treatment.