Utjecaj predtretmana infiltrirajućim smolama na veznu čvrstoću ortodontskih tuba na demineraliziranu caklinu čovjeka

doctoral thesis

• Title (english): The Influence of resin infiltration pretreatment in the orthodontics bonding to demineralized human enamel
• Author: Marina Šimunović Aničić
• Mentor: Senka Meštrović (mentor)
• Committee member: Marina Lapter-Varga (predsjednik povjerenstva)
• Committee member: Ivana Miletić (član povjerenstva)
• Committee member: Sandra Anić Milošević (član povjerenstva)
• Committee member: Martina Šlaj (član povjerenstva)
• Committee member: Zdravko Schauperl (član povjerenstva)
• Granter: University of Zagreb; School of Dental Medicine; (Department of Orthodontics); Zagreb
• Defense date and country: 2021-07-07, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Dental Medicine; Orthodontics
• Universal decimal classification (UDC): 616.31 - Stomatology

Abstract

Dosadašnja istraživanja dokazala su da infiltrirajuća smola može izvrsno penetrirati inicijalnu karijesnu leziju te je tako stabilizirati. Svrha ovog istraživanja bila je procijeniti veznu čvrstoću ortodontskih tuba lijepljenih s različitim adhezivima na demineraliziranu caklinu prethodno tretiranu infiltracijskom smolom. Također, cilj je bio usporediti dobivene vrijednosti vezne čvrstoće s vrijednostima na zdravoj caklini. Četrdeset i osam ekstrahiranih intaktnih gornjih i donjih trećih molara podijeljeno je u četiri skupine (n = 12), prekriveni su s lakom za nokte, osim područja od 4 x 4 mm te potom stavljeni u demineralizacijsku otopinu
(14 dana, 37 ºC), osim kontrolne skupine. Grupa 1: zdrava caklina + Transbond XT, grupa 2: demineralizirana caklina + ICON+ Transbond XT, grupa 3: demineralizirana caklina + ICON + Scotchbond, grupa 4: demineralizirana caklina + ICON + Assure PLUS. Vezna čvrstoća kvantificirana je u megapaskalima (MPa) i statistički analizirana (ANOVA, p ≤ 0.05). Indeks zaostatne smole analiziran je pod stereomikroskopom (10 x povećanje). Najveće vrijednosti vezne čvrstoće utvrđene su u grupi 4 te je razlika bila statistički značajna (F = 14,37; p = 0,000). Nije pronađena razlika između četiri skupine u vrijednostima ARI indeksa.
Zaključno, nema dokaza da demineralizirana caklina infiltrirana smolom smanjuje veznu čvrstoću ortodontskih elemenata. Vezna čvrstoća izmjerena u skupini gdje je korišten Assure PLUS-om pokazala je značajno veće vrijednosti u usporedbi s ostale tri skupine.

Abstract (english)

Introduction: The fixed orthodontic appliances may enhance plaque accumulation and lead to the progress of both demineralization and caries lesions, especially in patients with inadequate oral hygiene. Further, white spot lesion (WSL) can be seen after just four weeks of a fixed orthodontic appliance being fitted. The overall prevalence of WSLs ranges from 2– 96% depending on the assessment procedure of assessment of the lesions, whether or not any such defects were present before treatment and whether or not fluoride supplements were used during treatment. The altered enamel structure of teeth with initial caries lesions may reduce the shear bond strength (SBS) between orthodontic brackets and the enamel surface at the beginning of orthodontic treatment, as well as during treatment if the rebonding of the brackets is required. If bracket bonding is to be performed on demineralized enamel, it is advisable to stabilize and protect the demineralized enamel lesion prior to the reapplication of the bracket. Prior research reveal that low-viscosity resin is able to significantly penetrate initial caries lesions, which leads to their stabilization. The optical appearance of WSLs was also found to be improved by resin infiltration, with the achieved concealment being shown to remain stable in one-year interval in vivo. Aim: The aim of the present study was to assess the SBS of orthodontic brackets bonded with different adhesives to demineralized human enamel that had been treated with a low-viscosity resin infiltrant. It also aimed to compare the achieved bond strengths to those achieved in relation to sound enamel, as well to compare the ARI score between the four tested groups. Materials and methods: A total of 48 newly extracted third molars were collected, randomly allocated in four groups (n= 12), covered with a nail varnish, with 4 x 4 mm of uncoated area. Groups 2, 3 and 4 were immersed in Buskes demineralizing solution (14 days, 37 ºC) and Group 1 remained untreated. Group 1: sound enamel + Transbond XT; Group 2: demineralised enamel + ICON + Transbond XT; Group 3: demineralised enamel + ICON + Scotchbond Universal; Group 4: demineralised enamel + ICON + Assure Plus. Prior to adhesive application all the specimens were etched with 37% phosphoric acid for 15s. In all groups molar tubes were bonded with Transbond XT Paste. Prior to SBS testing, all the specimens were thermocycled (10,000 times Marina Šimunović Aničić, disertacija between 50 ∘C and 55 ∘C). SBS was measured in MegaPascals (MPa) and statistically analysed (ANOVA, p ≤ 0.05). The mode of failure was assessed microscopically at 10xmagnification. Results: The highest bond strength (20.3 MPa) was measured by molar tubes bonded with Assure Plus on demineralized enamel and the difference was statistically significant (p ≤ 0,001). No statistically significant differences were found among Groups 1, 2 and 3. No statistically significant between-group difference was observed for ARI scores. Conclusion: Based on our research, there is no evidence that resin infiltrated demineralized
enamel surface reduces the SBS of the orthodontic brackets. Thus, the bonding of the orthodontic elements with the adhesive system on the infiltrated area can be performed without risk of reducing the SBS. SBS measured in the Assure PLUS group was significantly higher compared to two other groups (Transbond XT and Scotchbond) as well as the control
group.

• Keywords: ortodoncija; zubna caklina; demineralizacija zuba; posmična čvrstoća
• Keywords (english): Orthodontics; Dental Enamel; Tooth Demineralization; Shear Strength
• Language: croatian
• URN:NBN: urn:nbn:hr:127:988761
• Promotion: 2021
• Study programme: Title: dental medicine; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, područje biomedicine i zdravstvo, polje dentalna medicina (doktor/doktorica znanosti, područje biomedicine i zdravstvo, polje dentalna medicina)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2021-08-24 08:38:10