Non-invasive caries treatment is a major focus in modern dentistry. The present study was designed to evaluate the effectiveness of monomeric self-assembling peptide P 11-4 (SAP P 11-4) in combination with fluoride varnish or polymeric self-assembling peptide matrix (SAPM) in treatment of non-cavitated occlusal caries. Ninety children and adolescents were included in this randomized, gold-standardcontrolled clinical trial. Test Group 1 received SAP P 11-4 and twice fluoride varnish at baseline and Day 180, Test Group 2 received SAP P 11-4 on baseline and twice weekly SAPM (home-application), and Control Group received fluoride varnish on baseline and Day 180. Caries progression was measured by laser fluorescence, Nyvad Caries Activity, ICDAS-II-codes, and investigator assessments. Laser fluorescence changes demonstrated superior results for Test Group 1 and 2, as values decreased compared to an increase for the Control Group (p < 0.0005). ICDAS-II codes at Day 360 showed partial regression for Test Group 1 (6.7%) and Test Group 2 (20.0%) and partial progression for Control Group (23.3%) (p < 0.01). Nyvad Caries Activity yielded superior caries inactivation for Test Groups, compared to Control Group (p = 0.002). This trial showed that SAP P 11-4, applied either in combination with fluoride varnish or twice weekly SAPM, was a superior treatment for early caries compared to fluoride varnish alone. Caries levels have significantly decreased over the past decades, partially due to the introduction of fluoride in various forms 1. However, despite the promising efforts and results worldwide, caries levels have remained high, and caries is still the most common disease worldwide 2. Recent efforts to lower caries levels have focused on treating early carious lesions non-invasively, as there is consensus that only early intervention, prior to cavitation, can lead to a regression of the caries to a more healthy state 3,4. Novel therapeutics have been called for, and promising approaches are based on biomimetic research and development. Biomimetic concepts fall into two categories, either based on amelogenin or derivatives thereof, or on rationally designed and screened systems 5,6. There is substantial research in the field, yet most of it is in vitro-based. The exceptions are recent clinical investigations of the rationally designed self-assembling peptide P 11-4 applied either in its monomeric form (SAP P 11-4) 5,6 or its polymeric form as a self-assembled peptide matrix (SAPM). This is the first clinical trial investigating the combined effect of SAP P 11-4 and SAPM in treatment of early carious lesions. SAP P 11-4 has been systematically investigated 7. The self-assembling peptide was rationally designed to provide favourable physicochemical characteristics for nucleation of hydroxyapatite (HA) on the surface of the formed fibres of the 3D matrix 8,9. The mechanism of action of SAP P 11-4 in the remineralization of enamel was proposed early on and has been proven since 10,11. When monomeric SAP P 11-4 is applied onto th...

Aim of this study was to analyze Shear Bond Strength (SBS) and Adhesive Remnant Index (ARI) of ceramic and metallic orthodontic brackets bonded to zirconia or lithium-disilicate ceramics used for prosthetic restorations, conditioned with hydrofluoric acid (HFA) or phosphoric acid (PhA), as well as to determine the Porcelain Fracture Index (PFI), in order to examine the condition of the ceramic surface after debonding. Material and methods The research was conducted on 96 prepared all-ceramic samples divided into 8 groups combined from the type of ceramic material, orthodontic brackets, and surface conditioning. SBS was tested with Universal Testing Machine, and the samples were analyzed using a Scanning Electron Microscope, to determine ARI and PFI. Statistical data were processed using ANOVA, with the level of significance α = 0.05. Results Lithium-disilicate showed better bond strength in almost all groups. However, no significant difference between the groups was noticed and none of the factors had a significant influence on the mean values of SBS (p>0.05). Nevertheless, ARI significantly depended on the type of bracket (p = 0.005), and PFI significantly depended on the type of etchant (p = 0.029). Conclusion The use of HFA for surface etching of zirconia and lithium-disilicate, does not cause a significant increase in the SBS values as compared to etching with PhA and silane application. Furthermore, HFA can weaken the surface structure of the ceramic, and considering its toxicity, might not be the best suitable conditioner prior to orthodontic bonding to lithium disilicate, and in particular to zirconia, also taking into account its crystalline structure.

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Background Bonding to ceramic restorations remains a major challenge to orthodontists, especially due to an increasing number of adults seeking orthodontic treatment. Aims The objective of this research was to investigate the influence of two chemical methods used for surface conditioning of ceramic crowns, on shear bond strength (SBS) of metallic and ceramic orthodontic brackets bonded to ceramic surfaces. Methods The study was conducted on 48 prepared specimens of metallic and ceramic orthodontic brackets bonded to ceramic crowns, conditioned with two different etching materials: hydrofluoric acid (HFA), or phosphoric acid, and subsequently, silane. SBS was tested using Universal Testing Machine. The samples were analysed using Scanning Electron Microscope, to determine adhesive remnant index (ARI). Statistical data was processed with ANOVA, and ARI was evaluated using x 2 test, with level of significance α=0.05. Results SBS values of the groups etched with HFA and silane, compared to the groups etched with phosphoric acid and silane, are not significantly increased. However, ceramic brackets show significantly higher SBS values than metallic brackets. Conclusion Both types of ceramic surface conditioning procedures have similar features and provide strong enough SBS values to realize the orthodontic treatment. Also, the assumption that only the type of bracket significantly affects the SBS value can be accepted.