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SUMMARY Objectives: For deep carious lesions, selective carious tissue removal (leaving soft dentin close to the pulp) is suggested. Afterward, different restoration materials, such as resin composites or glass hybrids (GHs), can be placed. Many dentists also apply setting or non-setting calcium hydroxide liners before restoration. We compared margin integrity and susceptibility for secondary caries in differently restored premolars in vitro. Methods: In 48 extracted human premolars, artificial residual lesions were induced on pulpo-axial walls of standardized cavities. Teeth were restored using a GH (Equia Forte) or adhesively placed resin composite restoration (OptiBond FL and Tetric EvoCeram) without any liner (RC), resin composite restoration with a non-setting calcium hydroxide liner (RC_NCH), or resin composite restoration with a setting calcium hydroxide liner (RC_SCH). After thermomechanical cycling, groups (n=12) were compared regarding their gingivocervical margin integrity (proportion of irregularities, microgaps, gaps >5 μm, overhangs). Teeth were then submitted to a continuous culture Lactobacillus rhamnosus biofilm model. After 14 days, bacterial numbers in biofilms, along tooth-restoration margins and mineral loss (ΔZ) of secondary lesions, were determined. Results: GH and RC_NCH showed significantly higher proportions of irregularities than RC and RC_SCH (p0.05). Conclusions: GH and composites lined with non-setting calcium hydroxide showed reduced margin integrity compared with non-lined composites or composites lined with setting calcium hydroxide. This did not increase susceptibility for secondary caries.

SUMMARYThe decrease in caries prevalence in many industrialized countries and the improved knowledge about the etiology and pathogenesis of caries have shifted the focus of caries therapy over the past decades toward less invasive approaches. Studies on caries progression indicate that it is generally quite slow in most patients today which should lead to a reconsideration of the practice of early invasive intervention. Today noninvasive (eg, fluorides) and microinvasive (occlusal sealing, proximal infiltration) therapeutic options that address etiological factors are gaining importance. The goal of these therapies is to heal or at least to slow down the progress of the disease. Noninvasive treatments are mainly related to controlling pathogenic factors (ie, sugar consumption) and enhancing protective factors (mainly oral hygiene and fluorides). Microinvasive treatments do not rely on the compliance of the patient as much, since these treatments include a resinous material that is applied to serve as a diffusion barrier for acids formed by cariogenic bacteria in the overlying plaque. To establish a minimum intervention treatment strategy for caries, the disease must be diagnosed at an early stage. In addition to assessing caries lesions in single teeth, individual risk factors need to be identified so that the underlying causes related to patients' behavioral patterns that led to the disease can be addressed as well. The patient should be informed about the scientific evidence related to the treatment choices in a participative atmosphere. Decision trees may help to make the range of findings comprehensible and the therapeutic shared decision-making process understandable to the patients.

SUMMARY Objective The load capability of post-restored endodontically treated teeth (ETT) can be determined at different restorative stages. It was the aim of this study to compare the load capability of ETT at these stages. Materials and Methods Maxillary central incisors were divided into 4 groups (n=10) and endodontically treated. Specimens were restored with: (I) only glass fiber posts (GFP); (II) GFP and composite build-up with 2 mm ferrule; (III and IV) with additional adhesively luted all-ceramic crowns. Group (I) to (III) were statically loaded, and group (IV) was exposed to thermomechanical loading (TML) and subsequent static loading. Results The lowest median load level of 73 N was determined for group (I). The maximum median load value of 331 N was found for group (III). The comparison of Fmax [N] of group (I), (II) and (III) revealed significant differences between the groups (p Conclusion Every additional restorative step torwards a final crown-restored ETT significantly increased the load capability. TML prior to load-to-fracture testing of the complete restorative complex, ie. post, core and crown, significantly decreased maximum load capability.

This study compared the progression of sealed initial enamel lesions penetrated with a fissure sealant (Helioseal, Vivadent) or various adhesives (Heliobond, Excite, Vivadent; Resulcin, Merz; Solobond M, Voco; Prompt L-Pop, 3M-ESPE) after exposure to a demineralizing solution, in vitro. From 27 bovine teeth, 54 enamel specimens were prepared and covered with nail varnish (control), thus obtaining three windows for treatment. After demineralization (pH 5.0; 14 days), two of the windows (A, B) were etched with phosphoric acid (20%; 5 seconds); whereas, the third area served as the control (C). The specimens were divided randomly into six groups (n=9), and the material was applied (90 seconds) either once (A) or twice (B). Light-curing followed each application. Half of the area of each specimen window was then covered with nail varnish, and the samples were again stored in the demineralizing solution (pH 5.0; 14 days). The specimens were cut perpendicular to the surface, and both enamel slabs were studied after infiltration using a fluorescent, low viscous resin (VIRIN) and confocal microscopy (CLSM). Lesion depths were calculated (ImageJ) from the surface to that point in the lesion where the grey values clearly changed to a darker grey. After demineralization, mean lesion depths (SD) (14 days) were measured at 105 (21) microm. The second demineralization led to a mean progression of the lesion depths of 52 (31)%. Adper Prompt L-Pop and Solobond M could not significantly prevent lesion progression after a single application (p > 0.05; t-test); however, the second application of Solobond M significantly decreased lesion progression (p < 0.05; t-test). Helioseal, Heliobond, Resulcin Monobond and Excite showed significantly better inhibition of the demineralization compared to the other materials (p < 0.05; Bonferroni). It can be concluded that the penetration of adhesives into initial lesions inhibited a further demineralization in vitro.