Adhesion of Hydroxyapatite Nanoparticles to Dental Materials under Oral Conditions.

Hydroxyapatite nanoparticles (nano-HAP) are receiving considerable attention for dental applications, and their adhesion to enamel is well established. However, there are no reports concerning the effects of HAP on other dental materials, and most of the studies in this field are based on in vitro designs, neglecting the salivary pellicle-apatite interactions. Thus, this in situ pilot study aims to evaluate the effects of three hydroxyapatite-based solutions and their interactions with different dental material surfaces under oral conditions. Hence, two volunteers carried intraoral splints with mounted samples from enamel and from three dental materials: titanium, ceramics, and polymethyl-methacrylate (PMMA). Three HAP watery solutions (5%) were prepared with different shapes and sizes of nano-HAP (HAP I, HAP II, HAP III). After 3 min of pellicle formation, 10 ml rinse was performed during 30 sec. Rinsing with water served as control. Samples were accessed immediately after rinsing, 30 min and 2 h after rinsing. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the particles, and SEM evaluated the pellicle-HAP interactions. SEM and TEM results showed a high variation in the size range of the particles applied. A heterogeneous HAP layer was present after 2 h on enamel, titanium, ceramics, and PMMA surfaces under oral conditions. Bridge-like structures were visible between the nano-HAP and the pellicle formed on enamel, titanium, and PMMA surfaces. In conclusion, nano-HAP can adhere not only to enamel but also to artificial dental surfaces under oral conditions. The experiment showed that the acquired pellicle act as a bridge between the nano-HAP and the materials' surface.

Effects of a full-mouth disinfection protocol on the treatment of type-2 diabetic and non-diabetic subjects with mild-to-moderate periodontitis: one-year clinical outcomes.

OBJECTIVES: This study compared the clinical effects of a full-mouth disinfection (FMD) protocol for the treatment of mild-to-moderate periodontitis in type 2 diabetic and non-diabetic subjects for up to 1 year. Secondary aim was to evaluate the effects of this therapy on the salivary levels of periodontal pathogens between diabetics and non-diabetics. MATERIAL AND METHODS: Twenty-six type 2 diabetic subjects and 28 non-diabetic subjects with mild-to-moderate periodontitis received full-mouth scaling and root planing within 24 h, application of chlorhexidine digluconate (CHX) gel in pockets and tongue plus CHX rinses for 14 days. Clinical monitoring was performed at baseline, 3, 6, and 12 months post-therapy. Salivary levels of red complex bacterial species were evaluated at baseline, 6, and 12 months post-therapy by qPCR. RESULTS: Intention-to-treat analyses were performed for seven diabetics and three non-diabetics that did not return for the 12-month evaluation. Most clinical parameters improved significantly at 3, 6, and 12 months post-therapies for both groups (p < 0.05). Overall, there were no significant differences in clinical parameters between groups after therapy (p > 0.05). At 1 year, 39.3% and 50.0% of the non-diabetic and diabetic subjects, respectively, achieved the desired clinical endpoint for treatment (≤ 4 sites with probing depth ≥ 5 mm) (primary outcome variable) (p > 0.05). FMD did not promote changes in the salivary levels of pathogens in either of the groups (p > 0.05). Levels of T. forsythia were lower in diabetic than in non-diabetic subjects at 6 months post-therapy (p < 0.05). CONCLUSIONS: Type 2 diabetic subjects and systemically healthy subjects with mild-to-moderate periodontitis responded similarly to the proposed FMD protocol for up to 1 year. CLINICAL RELEVANCE: There is a general thought that diabetics do not answer as well as non-diabetics to periodontal treatments. However, this study showed that diabetics and non-diabetics respond equally to the FMD protocol. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02643771.

A systematic review and meta-analysis on the effects of crown lengthening on adjacent and non-adjacent sites.

OBJECTIVES: The objective of the study was to assess the impact of periodontal crown lengthening surgery on clinical parameters at adjacent and non-adjacent sites compared to treated sites. MATERIAL AND METHODS: An electronic search was carried out on MEDLINE-PubMed, The Cochrane Library, and ISI Web of Science databases between 1978 and 2015. Methodological quality assessment was based on Cochrane recommendations. Meta-analyses were assessed with RevMan 5.0 and heterogeneity between studies by the Higgin test (I 2). Clinical attachment level (CAL) and probing depth (PD) were the primary outcome variables. Four case series studies were included and three in the meta-analysis. All studies showed high risk of bias. RESULTS: The surgery promoted significant changes in treated, adjacent, and non-adjacent sites. There were greater changes in PD (mean difference -0.14, 95 % CI -0.18 to -0.10, p < 0.00001) and CAL (mean difference 0.16, 95 % CI 0.13 to 0.20, p < 0.00001) in treated sites when compared to adjacent and non-adjacent sites for PD (mean difference -0.09, 95 % CI -0.12 to -0.05, p < 0.00001) and CAL (mean difference 0.91, 95 % CI 0.87 to 0.94, p < 0.00001). CONCLUSION: Crown lengthening surgery results in changes of clinical parameters in treated, adjacent, and non-adjacent sites. CLINICAL RELEVANCE: Clinical and esthetic alterations on the adjacent/non-adjacent teeth can lead to clinical and esthetic alterations, which must be considered in surgical planning.