Zahlreiche Ursachen sind für eine Infektion des Pulpakomplexes verantwortlich. Beispielsweise können Karies, Traumata oder auch Parodontitis mit einer mikrobiellen Besiedlung des Wurzelkanalsystems einhergehen. Letztendlich führt in den meisten Fällen das Eindringen dieser Bakterien zu einer Entzündung der Pulpa respektive des periapikalen Komplexes. Die alleinige chemomechanische Reinigung der Wurzelkanäle führt in der Regel nicht zu einer ausreichenden Eliminierung des endodontischen Mikrobioms. Deshalb kommen neben konventionellen Spüllösungen während der Wurzelkanalaufbereitung häufig zusätzliche Desinfektionsmethoden zum Einsatz – z. B. schall- bzw. ultraschall- oder plasmabasierende Systeme oder Lasersysteme. Die Kombination aus chemomechanischer Wurzelkanalbehandlung und adjuvanter, z. B. mithilfe der Lasertechnik umgesetzter Therapiemethoden können eine effektive Keimreduktion und als weiteren Effekt entzündungsfreie Strukturen schaffen bzw. die Ausheilung, was wiederum nicht nur für den endodontischen, sondern auch allgemeinmedizinischen therapeutischen Erfolg maßgeblich sein kann. Manuskripteingang: 02.03.2024, Manuskriptannahme: 06.03.2024 Schlagwörter: Endodontie, Desinfektion, Laser, Photosensibilisator, Aktivierung von Spüllösungen

Objectives: The aim of this in-vitro-study was to investigate the adaption behaviour and homogeneity of retrograde root canal filling materials as well as the impact of various cavity preparation forms. Methods: A total of 135 human single-rooted teeth were filled with gutta-percha after endodontic treatment. The specimens were randomly assigned to one of nine series (n=15). Specimens without retrograde root filling were used as the control group. The other specimens were divided into two subgroups according to the sonically supported retrograde preparation form (parallel or retentive preparation) which contain four material groups in each case (BiodentineTM, Pro RootTM MTA, Super-EBA^®, Ketac filTM Plus Aplicap). Afterwards three histological cuts were prepared at 1 mm, 2 mm, and 3 mm distance from the apex. The following criteria were examined using an optical microscope (5x zoom): imperfect margin, maximal marginal gap, and the number of air pockets in each section. Results: The statistical evaluation revealed significantly better results for retentive retrograde preparation regarding the proportion of imperfect margin and the amount of air pockets than parallel preparation (p≤ 0.05, Tukey's test). The pairwise comparison of maximal marginal gap showed no significant differences (p>0.05, Tukey's test). For the groups filled with Ketac filTM Plus Aplicap, a significantly higher proportion of maximal marginal gaps compared to all other materials (p≤ 0.05, Tukey's test) was evaluated. Furthermore, significant differences could be found considering imperfect margins compared to Pro Root MTA fillings, and air pockets compared to the fillings with Pro Root MTA, Biodentine and the control group (p≤ 0.05, Tukey's test). Conclusions: The preparation form and the selection of the retrograde root filling material during an apicoectomy can have a significant influence on the adaptation behaviour and homogeneity of the retrograde root filling and therefore might have an influence on the clinical outcome. Schlagwörter: retrograde Cavities, root canal filling materials, cavity preparation

Objectives: The aim of the present study was to investigate straightening of curved root canals after the engine-driven nickel-titanium systems Hero (Micro Mega), Revo-S (Micro Mega), Twisted Files (Kerr Endodontics), and Mtwo (VDW) were used for root canal preparation. Methods: A total of 60 root canals in extracted human teeth with a curvature of at least 25° were prepared. In each case, 15 canals were randomly assigned and prepared with the Hero 642 System (H), the Revo-S System (R), the Twisted File System (T), and the Mtwo System (M) according to the manufacturer's instructions. The sequence for strongly curved canals, respectively wide canals was used. The degree of straightening was evaluated by superimposition of standardised digital x-ray images taken before and after root canal preparation. These images were generated from X-rays of 2 planes which were at an angle of 90° to each other. Results: The statistical analysis showed a significant influence of the rotary systems used to straighten the root canals (p 0.001, ANOVA). For the four-test series, the following straightenings were evaluated (mean values and standard deviations in °): H: 4.78±3.24, R: 7.67±5.04, T: 5.07±2.91 and M: 4.23±3.72. Pairwise comparison showed significantly higher straightening in specimens treated with Revo-S (R) compared to the other systems (p≤0.05, Tukey's Test). The comparison of straightening within the other groups H, T, and M showed no significant differences (p>0.05, Tukey's Test). Conclusions: Regarding the limitations of an in vitro study, it can be concluded that all root canal preparation systems were associated with canal straightening, while Revo-S significantly showed the strongest straightening. Schlagwörter: root canal treatment, rotary NiTi system, straightening, endodontics, engine-driven preparation devices

Objectives: The purpose was to gain an overview of the oral health status of Ghanaian pre-school and school-aged children in rural and urban areas between the ages of 3 and 12 years in the southern area of the country. The study was carried out in 2017 and focused on identifying differences between these areas in terms of caries prevalence. Methods: The study was designed as a socio-epidemiological cross-sectional survey to include Ghanaian children and young adolescents between 3 to 4, 6 to 7, and 12 to 13 years of age. The participants were recruited from nurseries and schools in Accra (Greater Accra Region), representing urban and Kpando (Volta Region), representing rural areas of Ghana. The dental examination was conducted according to WHO criteria by one standardised investigator. The total number of decayed, missing, and filled primary teeth (dmft) for 3, 4, 6, and 7-year-olds or permanent teeth (DMFT) for 12 and 13 year-olds were recorded. Results: A total number of 313 children (165 urban, 148 rural) were included and examined. The distribution of participants according to age was as follows: 3 to 4 years (n=62), 6 to 7 years (n=47) and 12 to 13 years (n= 73). The average dmft among 3 to 4-year-old children was 0.9 in urban and 1.5 in rural areas, and among 6 to 7-year-olds 0.8 and 1.4, respectively. The average DMFT among 12 to 13-year-old adolescents was 0.9 and 0.3 respectively. Conclusions: The average dmft/DMFT-scores of Ghanaian children and adolescents ranges between 0.3 and 1.5. Whereas children from rural areas in the age groups 3 to 4 and 6 to 7 years consistently had fewer caries than those from urban areas, in contrast, adolescents in urban areas had a lower DMFT than those in rural areas. Schlagwörter: oral health, caries, Ghana, DMFT, children

Objectives: The aim of the study was to evaluate microtensile bond strength of a universal adhesive (Futurabond U, Voco GmbH, Germany) in self-etch and etch-and-rinse mode on human enamel and dentin compared with established systems. Additionally, the influence of an oxalate-containing desensitiser was evaluated. Methods: 180 human third molars were included. Standardised enamel and dentin specimens were prepared. 15 enamel and dentin samples each were assigned to one of the following experimental groups: Enamel groups: 1: Futurabond U, etch & rinse; 2: Futurabond U, self-etch; 3: Futurabond^® DC; 4: Solobond M. Dentin groups: 5: Futurabond U, etch & rinse; 6: Desensitizer, Futurabond U, etch & rinse; 7: Futurabond U, self-etch; 8: Desensitizer, Futurabond U, self-etch; 9: Futurabond DC; 10: Desensitizer, Futurabond^® DC; 11: Solobond M; 12: Desensitizer, Solobond M. The oxalate-containing desensitiser was applied in advance to the dentin samples. The adhesives were applied according to the manufacturer's instructions. After polymerization of the composite microtensile bond strength values were determined using a universal testing machine (Zwick Z 005). Results: Significantly higher values could be found for Futurabond U in the etch-and-rinse mode (21.45 MPa) compared to the self-etch mode (16.09 MPa) on enamel. Compared to the other two adhesives, no significant differences could be detected. The additional application of the oxalate-containing desensitiser in the case of dentin samples did not show any significant difference in the etch-and-rinse mode. For groups in self-etch mode, the desensitiser application resulted in significantly reduced tensile bond strength values compared to groups without desensitiser application. Conclusions: Regarding the limitations of an in-vitro study, it can be concluded that Futurabond U has very promising results on enamel and dentin compared to the established adhesives. The influence of an oxalate-containing desensitiser on the adhesion is only visible in the case of the self-etch application mode. Schlagwörter: desensitising, microtensile bond strength, universal adhesive, self-etch, etch-and-rinse

Objective: The purpose of this prospective randomized clinical study was to compare the clinical performance of the self-etching adhesive system Futurabond DC in combination with the composite GrandiSO and the influence of the additional application of the flowable resin composite GradioSO Heavy Flow after six months. Method: In 50 patients 32 class I and 68 class II cavities were placed with at least two restorations per patient. The adhesive system Futurabond DC was used for all the restorations. In one of the two fillings in each patient, an additional layer of the flowable resin composite GrandioSO Heavy Flow was applied in the entire cavity and separately light-cured. The fillings were placed under rubber dam. All materials were used as recommended by the manufacturer. Two clinicians evaluated the restorations at baseline, two week following placement, and at the six month recall visit according to the modified clinical criteria of Ryge. For this sensitivity, hypersensitivity, marginal discoloration, marginal adaption, recurrent caries, surface, color match, proximal contact and filling integrity were considered. All data were analyzed by Man-Whitney-U-test. Result: After six months 50 patients could be re-examined. All teeth remained vital and did not show any signs of postoperative sensitivity. Marginal adaption code Bravo could be evaluated in one filling (with flowable liner). In three teeth a marginal discoloration was scored as Bravo (two with and one without fowable liner). None of the teeth showed signs of secondary caries. Statistical analysis showed no significant difference between techniques for any of the evaluation criteria (p>0.05, Man-Whitney-U-test). Conclusion: After six months the use of a flowable composite showed no significant impact on the clinical performance of class-I and -II restorations. The self-etch adhesive Futurabond DC might be a promising alternative to other systems. This study was supported by Voco GmbH, Germany. Schlagwörter: clinical study, composite, direct restorations, flowable composite

Objectives: The aim of the present study was to determine the effect of four different desensitizing agents (Gluma Desensitizer, Admira Protect, Hyposen, VivaSens) on root surfaces de- and remineralization in vitro. Methods: The root surfaces of 90 freshly extracted caries-free human molars were thoroughly cleaned, thereby removing the cementum. The teeth were then coated with acid-resistant nail varnish, exposing a rectangular windows. All specimens were demineralized (De) for 14 days with acidified gel (HEC, pH 4.8, 37 degrees C). Before remineralization (Re) using a NaF-containing calcium-phosphate buffer solution one window was covered. Beside an untreated control group, the specimens were distributed among two main groups: In one group the desensitizer was applied before demineralization, in the other subgroup the desensitizer was applied after demineralization. From each tooth, two dentinal slabs were cut. The depth of the demineralized areas was determined using a polarized light microscope. Results: The comparison between de- and remineralized groups showed a significant reduction of lesion depth in all cases (p0.05, Tukeys test). In all cases application of the desensitizers prior to demineralisation resulted in significantly decreased lesion depths compared to the demineralization lesion depths without desensitizer application (p0.05, Tukeys test). Conclusions: It can be concluded that the demineralization of the root surface can be hampered by the application of desensitizing agents in vitro. Furthermore, remineralization might not be negatively affected by the used sealants. Schlagwörter: Dentin, Desensitizer, Demineralisation, Remineralisation, Dentin hypersensitivity

Objective: The present study was undertaken to evaluate the effect of alternative hemostatic agents used for pulpotomy such as ferric sulfate and 5% NaOCl on microtensile bond strength (mTBS) of two adhesive systems to pulpal floor dentin of primary teeth in vitro. Methods: Seventy-two extracted primary molars were included. Dentin specimens of the pulp chamber were obtained under standardized conditions. The specimens were randomly assigned to one of the six groups of twelve samples each: group PB-C: Prime&Bond, control group; PB-1: immersion for five minutes in ferric sulfate prior to bonding with Futurabond, PB-2: immersion for five minutes in 5% NaOCl prior to bonding; groups F-C, F-1 and F-2 followed the same procedure with Futurabond NR as adhesive. MTBS was measured 15 minutes after application of the corresponding compomer (Dyract/ Glasiosite) using an universal testing machine. Results: Statistical analysis showed a significant influence of the used dentin adhesive and the hemostatic agent (p 0.001, ANOVA). The immersion in 5% NaOCl before bonding procedure (PB-2, F-2) resulted in a significant reduction of mTBS compared to the untreated control groups (PB-C, F-C) (p 0.05, Tukey's test). Between the controls and ferric sulphate groups, significant differences could only be detected in the case of Futurabond NR (p 0.05, Tukey's test). Pairwise comparison between Prime&Bond and Futurabond showed no significant differences in all groups (p 0.05, Tukey's test). Conclusions: Within the limitations of an in vitro investigation it can be concluded that hemostatic agents used for pulpotomy might have an adverse effect on mTBS of adhesive systems. In the case the self-etch adhesive Futurabond NR both hemostatic agents reduced mTBS. Schlagwörter: pulpotomy, hemostatic age, dentin adhesives, microtensile bond strength

Objective: The aim of the present study was to evaluate the inflence of different concentrations of chlorhexidindigluconate (CHX) on microtensile bond strength (mTBS) of two self-etching dentin adhesives (Futurabond NR, Bond Force) in vitro. Methods: 150 extracted third molars were included in this study. All teeth were specially prepared allowing the simulation of dentin perfusion. The specimens were randomly assigned to one of the ten groups of fifteen samples each: group F-C: Futurabond NR, control group (no CHX-application); F-0.2: immersion for five minutes in 0.2% CHX prior to bonding with Futurabond, F-2: immersion for five minutes in 5% CHX prior to bonding, F-5: immersion for five minutes in 2% CHX prior to bonding, groups B-C, B-0.2, B-2 and B-5 followed the same procedure with Bond Force as adhesive. MTBS was measured 15 minutes after application of the composite (Tetric Ceram) using an universal testing machine. Results: Statistical analysis showed a significant influence of the used dentin adhesive and the pre-treatment with CHX in different concentrations (p 0.001, ANOVA). The application of 2% and 5% CHX before bonding procedure (F-2, F-5, B-2, B-5) resulted in a significant reduction of mTBS compared to the untreated control groups (F-C, B-C) (p 0.05, Tukey's test). Between the controls and the 0.2% CHX-groups, no significant differences could be detected (p 0.05, Tukey's test). Pairwise comparison between Futurabond and Bond Force showed no significant differences in all groups (p 0.05, Tukey's test). Conclusions: Within the limitations of an in vitro investigation it can be concluded that CHX in higher concentrations affected the mTBS of both tested self-etching adhesive systems. Schlagwörter: CHX, microtensile bond strength, self-etch adhesives

Objectives: The aim was to evaluate the effect of different concentrations of NaOCl on microtensile bond strength (mTBS) of a dual-curing total-etch adhesive (LuxaBond-Total Etch) in combination with a dual-curing composite (Luxacore Z-Dual) on pulpal dentin in vitro. Material and Methods: Seventy-two extracted third molars were included. Dentin specimens of the pulp chamber were obtained under standardized conditions. The specimens were randomly assigned to one of the six groups of twelve samples each: L-C: Luxabond/Luxacore (light-curing), control (no NaOCl-application); L-1: immersion in 1% NaOCl (24 hours) before bonding, L-5: immersion in 5% NaOCl (24 hours) before bonding; groups C-C, C-1, C-5 followed the same procedure using the self-curing mode. Results: After light-curing following mTBs could be observed (MPa): L-C: 30.9 (±3.7); L-1 26.6 (± 4.8); L-5: 19.8 (± 2.0). After using the self-curing mode mTBS was as followed: C-C:23.1 (± 4.4); C-1: 21.5 (4.6); C-5: 18.3 (2.1). Statistical analysis showed a significant influence of the used curing method and the different NaOCl concentrations (p0.001, ANOVA). The application of 1% and 5% NaOCl before bonding resulted in a reduction of mTBS. In the case of 5%, this difference was significant. Pairwise comparison between both curing groups showed no significant differences between L-C/C-C and L-1/C-1 (p 0.05, Tukey's test). Conclusions: It can be concluded that the curing method might have an influence on mTBS. The application of higher concentrations of NaOCl prior to bonding decreases mTBS. Clinical relevance: NaOCl is commonly used in endodontic treatment and might have an influence on mTBs. Schlagwörter: microtensile bond strength, NaOCl, dentin adhesive