Effect of experimental dentin etchants on dentin bond strength, metalloproteinase inhibition, and antibiofilm activity

OBJECTIVE

this study evaluated dentin microtensile bond strength (µTBS) and failure modes (at 24 h and one year), bonding interface regarding hybridization, surface morphology regarding demineralization, in situ metalloproteinase (MMP) activity, and antibacterial effect of three dentin etchants compared to 35% phosphoric acid (PA).

MATERIALS AND METHODS

The Adper Single Bond 2 adhesive (3 M Oral Care) was applied on moist dentin etched with PA (control) or on air-dried dentin etched with 3% aluminum nitrate + 2% oxalic acid (AN), 6.8% ferric oxalate + 10% citric acid (FO), or 10% citric acid (CA). The µTBS test used 40 human teeth (n = 10). Failure modes and surface morphology were analyzed by scanning electron microscopy (n = 3), while bonding interface morphology and MMP activity were evaluated by laser scanning confocal microscopy (n = 3). Antibacterial activity was evaluated against S. Mutans biofilm by means of viable cells count (CFU/mL).

RESULTS

PA presented the highest bond strengths regardless of aging time. PA, AN, and CA showed stable bond strengths after one year of storage. Adhesive and mixed failures were predominant in all groups. Thin hybrid layers with short resin tags were observed for the experimental etchants. The AN-based etchant was able to inhibit MMP activity. All tested etchants presented antibacterial activity against S. Mutans biofilm.

SIGNIFICANCE

This study suggests different dentin etchants capable of inhibiting MMP activity while also acting as cavity disinfectants.

Evaluation of patients' perception of gingival recession, its impact on oral health-related quality of life, and acceptance of treatment plan

Objective: Gingival recessions (GR) may cause aesthetic and hypersensitivity complaints which might affect oral health-related quality of life (OHRQoL). The aim of this study was to evaluate the patients' awareness of their own GR, the impact of GR on OHRQoL and the acceptance of suggested treatment modalities.Materials and Methods: This cross-sectional study was conducted with 205 patients. The demographic variables were recorded and patients' perception of GR was questioned. Full-mouth examination was carried out and clinical parameters were recorded. Gingival recessions, GR related complaints were evaluated and GR treatments were suggested and acceptance were also recorded by the examiner. The patients filled out OHRQoL-United Kingdom (OHRQoL-UK) questionnaire regarding to their GR and were asked if GR have/would have impact on oral health and if the GR will/would get worsen. Data was analysed with independent t test and Mann-Whitney U test.Results: 4819 teeth were evaluated and 733 GR examined in 147 patients. Fifty-seven patients were unaware of their GR. A strong belief that GR have impact on oral health (88.78%) and GR will progress (86.34%) was detected. Acceptance of treatment was increased and non-invasive modalities were preferred if patients had complaints. The awareness of GR status increases and the misperception decreases the OHRQoL-UK scores. The results revealed that hypersensitivity decreases the OHRQoL-UK scores and aesthetic concerns and hypersensitivity decreases the OHRQoL-UK physical scores significantly (p < .05).Conclusions: The results indicated that the patients might be unaware of their GR and the GR related factors may lead to poorer OHRQoL.