Assessment of colour modifications in two different composite resins induced by the influence of chlorhexidine mouthwashes and gels, with and without anti-staining properties: An in vitro study.

OBJECTIVES: Chlorhexidine (CHX)-based products are the most effective chemical agents used in plaque control and oral disinfection. One of their side effects is tooth and restoration staining. For this reason, CHX products with anti-discolouration systems (ADS) have been developed. The aim of this in vitro study was to compare different CHX-based products (gel and mouthwash) with or without ADS in composite colour modification. METHODS: Two hundred specimens were created, 100 of which were made of packable composite and 100 of flowable composite. After 24 h, colour coordinates (L*, a*, b*, C*, h°) were recorded using a spectrophotometer (T0). Then, all samples were subjected to a CHX/tea staining model and immersed in human saliva for 2 min. Composite specimens were divided in 10 groups (N = 20). Control groups (PC, FC) were soaked in distilled water and test groups (PG, PGads, FG, FGads, PM, PMads, FM and FMads) were immersed in CHX-based solutions or brushed with CHX gel. Then the cycle was repeated 6 times, and colour differences (ΔEab and ΔE00 ) were finally calculated. RESULTS: Through flowable composites, FC and FG showed the highest colour differences, respectively ΔEab = 3.48 ± 1.0, ΔE00 = 2.24 ± 0.6 and ΔEab = 2.95 ± 1.3, ΔE00 = 1.53 ± 0.6. In the composite groups instead, PM and PMads showed the highest colour differences, respectively ΔEab = 2.78 ± 1.3, ΔE00 = 1.94 ± 0.8 and ΔEab = 2.71 ± 1.4, ΔE00 = 1.84 ± 0.9. CONCLUSIONS: CHX-containing products are able to cause stains on restorative composite materials. Discolouration is more likely to occur in flowable composites than packable composites, and ADS-containing products cause fewer pigmentations than CHX products without ADS. Packable composites showed more staining after mouthwash treatment, whereas flowable composites underwent higher discolouration after treatment with gels.

Single tooth anaesthesia: a new approach to the paediatric patient. A clinical experimental study.

AIM: The objective of this study is to assess the efficacy of the STA Wand System with respect to pain and fear reduction in paediatric patients and by using the Single Tooth Anaesthesia (STA) technique. MATERIALS AND METHODS: Patients included children and teenagers between 6 and 17 years of age, who required the administration of local anaesthesia prior to expected treatments. Local anaesthesia was performed by means of the electronic STA Wand System (Milestone scientific., Inc.) adopting the Single Tooth Anaesthesia (STA) technique. Pre- and post-anaesthesia, the patients were asked to complete the Wong-Baker faces image scale and the provider filled in the Frankl Scale. RESULTS: All treatments were completed successfully and no collaboration issues were recorded. Frankl's assessment showed that 91% of patients regarded dental experience positively. The efficacy of the computer-assisted anaesthesia was at 100% when treating primary teeth, and 70% for procedures on permanent teeth. Almost the totality of treated patients (94%) gave a positive evaluation after having tried the device with STA technique. Only 6% of the patients assessed the procedure negatively. CONCLUSIONS: The STA technique allows for absence of anticipatory anxiety, absence of physical pain, no anaesthetic effects in the perioral tissues and a controllable, lower dosage of the anaesthetic liquid.