Microstructural Changes of Human Dentin Tubules after Citric Acid Immersion of Specimens Treated with Different Desensitising Approaches: An SEM Analysis.

PURPOSE: This in-vitro study aimed to evaluate the effectiveness and acid resistance on dentin surfaces following the application of a linear-oscillating device (LOD) with a hydroxyapatite-based polishing fluid, Er:YAG laser or sodium fluoride (NaF) used alone or in combinations for desensitising purposes. MATERIALS AND METHODS: Freshly extracted impacted third molars were used to obtain 120 specimens, all completely immersed in 1% citric acid for 5 min and divided randomly into 6 groups. Group I, with no treatment, served as the control; group II: Er:YAG laser (30 Hz, 60 mJ/pulse, 10 s); group III: NaF gel; group IV: LOD; groups V and VI: the combinations of NaF+Er:YAG and LOD+Er:YAG, respectively, were applied. Following these treatments, the effectiveness of each was evaluated in half of the specimens in each group (n = 10). The other half of the specimens (n = 10) served for acid-resistance testing. All evaluations were made on SEM photomicrographs. RESULTS: The post-treatment tubule diameters and numbers were the lowest with LOD+Er:YAG, followed by NaF+Er:YAG, LOD, Er:YAG and NaF. Paired comparisons revealed LOD+Er:YAG to be the best treatment method (p < 0.05). After 3 h of acid immersion, all treatments revealed significant increases (p < 0.05) in both tubule number and diameter study between post-treatment and post-acid immersion values. The exception was LOD+Er:YAG. LOD+Er:YAG showed the highest resistance to acid challenge, presenting the lowest increase in tubular diameters and numbers followed by NaF+Er:YAG, LOD, Er:YAG and NaF. CONCLUSION: Combined LOD+Er:YAG treatment revealed the highest effectiveness and acid resistance. Further clinical studies are warranted to confirm these in-vitro results.

Plaque Inhibitory Effect of Hyaluronan-Containing Mouthwash in a 4-Day Non-Brushing Model.

PURPOSE: Despite being the gold standard antiplaque agent, chlorhexidine (CHX) has many adverse effects that make scientists search for new agents to combat biofilms as effective as CHX. Hyaluronan, also known as hyaluronic acid (HA), is a natural polysaccharide with anti-inflammatory, antioxidant and bacteriostatic properties. The objectives were to evaluate the plaque inhibitory, and anti-inflammatory effects of HA mouthwash compared to CHX and distilled water (DW) in a 4-day non-brushing model together with the participants' preference to the used products. MATERIALS AND METHODS: Thirty-three systemically and periodontally healthy subjects were included in this randomised, double-blinded, crossover clinical study. Subjects were randomly assigned into three treatment-sequence groups to use three mouthwashes one after another, in three different time periods. After professional prophylaxis at day 1, subjects refrained from all oral hygiene measures and used mouthwashes that were individually allocated to them. On day 5, scoring of plaque index (PI) according to Turetsky modification of Quigley Hein Index system, modified gingival index (MGI) and measurement of gingival crevice fluid (GCF) volume were performed. Treatment satisfaction questionnaire form was given at the end of each experimental period. RESULTS: CHX showed statistically significant reduction in PI followed by HA (p = 0.048). No statistically significant differences were detected between HA and CHX in terms of MGI and GCF volume. For HA, subjects reported significantly better taste, less sensitivity, burning sensation, mouth dryness and numbness perception compared to CHX and DW. CONCLUSIONS: CHX revealed the best plaque inhibition closely followed by HA. Early gingival inflammatory changes were found similar for CHX and HA. Furthermore, HA was well accepted with better perceptions than CHX and DW.

Profilometric Analysis of Periodontally Diseased Root Surfaces After Application of Different Instrumentation Tools: An In Vitro Study.

Objective: The topography of the root surface plays an important role in plaque accumulation, cell adhesion, and periodontal healing. The aim of this study is to profilometrically evaluate the root surface changes following the instrumentation using different tools. Methods: Forty dentin blocks of buccal and lingual root surfaces were obtained from 20 single-rooted periodontally diseased hopeless teeth and randomly divided into 4 groups. Each group was subjected to different root instrumentation tools such as stainless steel (SS) Gracey curette (Group 1); titanium nitride (TIN) Gracey curette (Group 2); ultrasonic piezoelectric device with a special tip designed for root surfaces (H3) (Group 3); and Er:YAG laser (Er:YAG tip) chisel (Group 4). A calibrated clinician instrumented all surfaces in each group. The root surfaces were profilometrically evaluated before and after instrumentations. Results: There were no statistical differences between the initial roughness levels of the groups. TIN curettes revealed the most prominent effect on smoothing the surface, whereas the Er:YAG tip showed the highest roughness in comparison with the other root surface instrumentation tools. Conclusions: Considering the importance of root surface roughness after treatment for the success of periodontal therapy, the TIN curette was the most periodontally appealing tool followed by H3, SS curette, and Er:YAG tip.