[Bond strength of metal brackets to enamel with a Russian adhesive complex: an in vitro study]. / Sila adgezionnogo soedineniya emali zuba i metallicheskogo breketa, poluchennogo s pomoshch'yu otechestvennogo adgezivnogo kompleksa in vitro.

BACKGROUND: The era of using adhesives to fix brackets began in the 70s of the last century. There are eight generations of foreign-made adhesive systems for the restoration of teeth. However, until now, in orthodontics, the development of domestic adhesive systems with improved properties of adhesion of brackets to tooth enamel still important, especially in the posterior teeth. OBJECTIVE: The purpose of this work was to study the shear strength of fifth generation domestic adhesive between metal brackets and the enamel of molar teeth in laboratory conditions. MATERIAL AND METHODS: The study included 17 specimens of extracted maxillary molars embedded in acrylic resin blocks. Brackets from G&H Orthodontics (G&H Wire Company, USA) were fixed to the tooth enamel using the domestic Compofix (ortho) set. The enamel was treated with etching gel (37% phosphoric acid) for 30 seconds. Then the gel was washed off with water and the surface of the enamel was thoroughly dried. A primer was applied to the prepared surface with an applicator, inflated with a weak air flow for 5-10 seconds and photopolymerized for 20 seconds. The surface of the bracket was treated with degreaser, then a thin layer of adhesive was applied, and the sample was fixed to the enamel. Excess material was removed with an applicator. The samples were photopolymerized for 20 sec. Then, the shear bond strength of the adhesive was determined according to the method of GOST 31574-2012 on a (Zwick/Roell Z010 testing machine, Zwick, Germany). RESULTS: The shear strength of the adhesive joint obtained during the test is 13.54±1.01 MPa, the average value of the index of adhesive residues on the surface of the bracket was 23%±4%, which corresponds to the standard average values according to GOST. CONCLUSION: The tested domestic adhesive system of the fifth generation can be recommended for the practical work of an orthodontist.

[Comparative efficacy of Botox and surgical lip repositioning in the correction of gummy smile]. / Sravnitel'naya effektivnost' vvedeniya botoksa i khirurgicheskoi operatsii dlya korrektsii polozheniya gub pri desnevoi ulybke.

BACKGROUND: A smile plays an important role in determining a person's initial impression. OBJECTIVE: This study aims to evaluate the effectiveness of both injection botulinum toxin type A (botox) and surgical lip repositioning in the correction of the gummy smile due to hyperactive upper lip according to the resulting smile and the patients' satisfaction. MATERIAL AND METHODS: The study consisted of 24 patients: 12 received the BTX-A (botulinum toxin type-A) injection and the remaining 12 underwent the surgical procedure (lip repositioning). The patients rated their satisfaction according to their gingival display that was defined as the difference between the lower margin of the upper lip and the superior margin of the right incisor, and patients were followed at 2 weeks, 2 months, and 6 months. Post injection and post-surgery with changes documented by photographs. Both groups answered a questionnaire addressing the overall appearance and they were asked to rate the improvement of their smile according to a 5-point aesthetic scale. RESULTS: The patients rated the effects of BTX-A as highly favorable if we take into consideration that BTX-A had a temporary effect while the surgical procedure (lip repositioning) had a relapse likelihood of more than 80% because the lip reverted back to its original position with almost complete relapse after 6 months and not to mention the risks affiliated with the surgical procedures. CONCLUSION: BTX-A injection exhibits better results than those of surgery and had given safer and more satisfactory results and achieved the required cosmetic patient requirement than lip repositioning.

[Evaluation of the effect of sodium hypochlorite gel on composite bonding strength to enamel of primary teeth after salivary contamination: in vitro study]. / Primenenie gelya gipokhlorita natriya dlya uluchsheniya stsepleniya kompozitnogo materiala s emal'yu vremennykh zubov pri slyunnoi kontaminatsii.

OBJECTIVE: The study investigated the effect of 2%s odium hypochlorite gel application after post-etching salivary contamination on composite bonding strength to primary teeth enamel. MATERIAL AND METHODS: The sample consisted of 79 primary human teeth that were extracted no more than one month ago. The sample was randomly divided into four groups: (1) the control group (A) comprised 10 primary teeth, and composites were applied in the traditional manner without any salivary contamination; (2) the second group (B) consisted of 23 primary teeth in which salivary contamination was conducted after etching followed by re-etching and follow-up; (3) the third group (C) comprised 23 primary teeth in which saliva contamination was done after etching followed by washing, drying, and follow-up; and (4) the fourth group (D) comprised 23 primary teeth, in which salivary contamination was conducted after etching followed by application of sodium hypochlorite gel and follow-up. The samples were tested using the Testometric Tensile Strength Device (Testometric M350-10 kN, Testometric Ltd., UK) to measure the composite bonding strength to enamel of primary teeth. RESULTS: The arithmetic mean strength values in the research sample were ordered as followed: (A=13.39 MPa) > (D=11.82 MPa) > (C=8.07 MPa) > (B=6.15 MPa). The application of sodium hypochlorite gel after salivary contamination significantly improved the composite bonding strength to primary teeth enamel when compared with re-etching or only washing and drying. CONCLUSION: 15 s exposition of sodium hypochlorite gel with subsequent rinse and drying is recommended in case of saliva contamination of etched primary tooth enamel surface.