[Risk Factors for Postoperative Delirium after Cardiac Surgery]. / Risikofaktoren des postoperativen Deliriums in der Herzchirurgie.

Background Delirium is a common psychiatric disorder after cardiac surgery and predisposes patients to increased mortality and morbidity. Its prevention requires knowledge of the risk factors involved. Objective What are preoperative risk factors for postoperative delirium after cardiac surgery? Methods Prospective longitudinal study of 241 elective cardiac surgical patients with preoperative assessment of potential risk factors and delirium assessment twice daily over five postoperative days. Results 13 % of the patients experienced delirium. Reduced cognitive performance (OR: 3.80; 95 % CI: 1.66 - 8.66), higher comorbidity (OR: 1.36; 95 % CI: 1.07 - 1.7) and higher age (OR: 1.08; 95 % CI: 1.02 - 1.13) increased the risk of delirium. Conclusion Delirium after cardiac surgery is common. It occurs in particular in patients with low cognitive performance, higher comorbidity and higher age.

Influence of Cavity Lining on the 3-Year Clinical Outcome of Posterior Composite Restorations: A Randomized Controlled Clinical Trial.

The purpose of this randomized, split-mouth-designed controlled and single-blinded clinical study was to evaluate the 3-year clinical performance of Class I and Class II resin composite restorations placed with or without cavity lining with a flowable composite. Fifty patients with treatment needs in two premolars or molars were included. One of the teeth was restored using the nanohybrid composite (Grandio®SO, control group), in the test group a high viscosity flowable composite was additionally applied as a first layer. In both groups, the same self-etch adhesive system was applied. Clinical evaluation after 3 years was carried out using the modified USPHS/Ryge criteria. At the 3-year follow-up the recall rate was 92%. Four restorations failed in the test group (8.7%), three due to the loss of vitality and one after fracture. The control group exhibited a cumulative success rate of 100%, while the test group achieved a success rate of 91.3%. This led to significant differences in the annual failure rate (AFR) between the two groups, with rates of 0% and 2.9% (p < 0.05; Mann-Whitney U-test). After 3 years the cumulative survival rate including all restorations was 95.7%. Statistical analysis revealed significant differences for the parameters: tooth vitality, marginal discoloration, success rate, and AFR. The other parameters exhibited no significant differences. Consequently, the nanohybrid composite demonstrated excellent performance over a 3-year period, whereas the utilization of a flowable composite for the cavity lining did not appear to exert a beneficial influence on clinical outcomes.

How valid and applicable are current diagnostic criteria and assessment methods for dentin hypersensitivity? An overview.

OBJECTIVES: Although dentin hypersensitivity is a common clinical condition and is generally reported by the patient after experiencing a sharp, short pain caused by one of several different external stimuli, it is often inadequately understood. The purpose of this paper is to discuss different available diagnostic approaches and assessment methods used in order to suggest a basis to diagnose, monitor, and measure these challenging painful conditions related to dentin hypersensitivity in daily practice and scientific projects properly. MATERIAL AND METHODS: A PubMed literature search strategy including the following MeSH terms were used as follows: "dentin sensitivity"[MeSH Terms] OR "dentin"[All Fields] AND "sensitivity"[All Fields] OR "dentin sensitivity"[All Fields] OR "dentin"[All Fields] AND "hypersensitivity"[All Fields] OR "dentin hypersensitivity"[All Fields] AND "diagnosis"[Subheading] OR "diagnosis"[All Fields] OR "diagnosis"[MeSH Terms] AND "assessment"[All Fields] AND ("methods"[Subheading] OR "methods"[All Fields] OR "methods"[MeSH Terms]. Furthermore, alternative terms such as "validity," "reliability," "root," "cervical," "diagnostic criteria," and "hypersensitivities" were additionally evaluated. RESULTS: The literature search, also including the alternative terms and journals, revealed only a small number of specific papers related to valid diagnosis, diagnostic criteria, and assessment methods of dentin hypersensitivity. Outcomes from these publications showed that the response to different stimuli varies substantially from one person to another and is, due to individual factors, often difficult to assess correctly. Furthermore, the cause of the reported pain can vary, and the patient's description of the history, symptoms, and discomfort might be different from one to another, not allowing a reliable and valid diagnosis. CONCLUSIONS: The dental practitioner, using a variety of diagnostic and measurement techniques each day, will often have difficulties in differentiating dentin hypersensitivity from other painful conditions and in evaluating the success of a conducted therapy in a reliable way. CLINICAL RELEVANCE: Correct diagnosis of dentin hypersensitivity including a patient's history screening and a brief clinical examination in combination with the identification of etiologic and predisposing factors, particularly dietary and oral hygiene habits associated with erosion and abrasion, is essential. The relevant differential diagnosis should be considered to exclude all other dental conditions with similar pain symptoms.

The influence of parotid gland sparing on radiation damages of dental hard tissues.

OBJECTIVE: The aim of the present study was to evaluate whether radiation damage on dental hard tissue depends on the mean irradiation dose the spared parotid gland is subjected to or on stimulated whole salivary flow rate. MATERIAL AND METHODS: Between June 2002 and October 2008, 70 patients with neck and cancer curatively irradiated were included in this study. All patients underwent dental treatment referring to the guidelines and recommendations of the German Society of Dental, Oral and Craniomandibular Sciences prior, during, and after radiotherapy (RT). During the follow-up period of 24 months, damages on dental hard tissues were classified according to the RTOG/EORTC guidelines. The mean doses (D(mean)) during spared parotid gland RT were determined. Stimulated whole saliva secretion flow rates (SFR) were measured before RT and 1, 6, 12, 24 months after RT. RESULTS: Thirty patients showed no carious lesions (group A), 18 patients developed sporadic carious lesions (group B), and 22 patients developed general carious lesions (group C). Group A patients received a D mean of 21.2 ± 11.04 Gy. Group B patients received a D(mean) of 26.5 ± 11.59 Gy and group C patients received a D(mean) of 33.9 ± 9.93 Gy, respectively. The D(mean) of group A was significantly lower than the D(mean) of group C (p < 0.001). Additionally, the mean SFR 6 months after RT of group A was significantly higher than the mean SFR of group C (p < 0.01). CONCLUSIONS: Irradiation damage on dental hard tissue correlates with increased mean irradiation doses as well as decreased salivary flow rates. CLINICAL RELEVANCE: Parotid gland sparing resulting in a dose below 20 Gy reduces radiation damage on dental hard tissues, and therefore, the dose may act as a predictor for the damage to be expected.

The Interaction of Two Widely Used Endodontic Irrigants, Chlorhexidine and Sodium Hypochlorite, and Its Impact on the Disinfection Protocol during Root Canal Treatment.

In recent years, sodium hypochlorite and chlorhexidine digluconate have been the gold standard of irrigation solutions utilized within the disinfection protocol during root canal treatments. Nowadays, it is known that, during chemical disinfection of the root canal, consecutive application of sodium hypochlorite and chlorhexidine digluconate leads to the formation of an orange-brown precipitate. This precipitate is described as being chemically similar to para-chloroaniline, which is suspected to have cytotoxic and carcinogenic effects. Concerns also exist regarding its influence on the leakage of root canal fillings, coronal restorations, and tooth discoloration. The purpose of this article is to review the literature on the interaction of sodium hypochlorite and chlorhexidine digluconate on the tooth and its surrounding tissues, and to discuss the effect of the precipitate formed during root canal treatment. We further address options to avoid the formation of the precipitate and describe alternative irrigation solutions that should not interact with sodium hypochlorite or chlorhexidine digluconate.

Influence of Ascorbic Acid as a Growth and Differentiation Factor on Dental Stem Cells Used in Regenerative Endodontic Therapies.

BACKGROUND: Vitamin C is one of the major extracellular nonenzymatic antioxidants involved in the biosynthesis of collagen. It promotes the growth of fibroblasts, wound healing processes, and enhances the survival and differentiation of osteoblasts. The potential effects of ascorbic acid on human dental pulp cells (DPC) and the cells of the apical papilla (CAP) used in actual regenerative endodontic procedures remain largely unknown. In this study, we investigated the possible employment of ascorbic acid in the differentiation and regenerative therapies of DPC and CAP. METHODS: Nine extracted human wisdom teeth were selected for this study. Subpopulations of stem cells within DPC and CAP were sorted with the mesenchymal stem cell marker STRO-1, followed by treatments with different concentrations (0 mM, 0.1 mM, 0.5 mM, and 1.0 mM) of ascorbic acid (AA), RT-PCR, and Western blot analysis. RESULTS: FACS analysis revealed the presence of cell subpopulations characterized by a strong expression of mesenchymal stem cell marker STRO-1 and dental stem cell markers CD105, CD44, CD146, CD90, and CD29. Treatment of the cells with defined amounts of AA revealed a markedly increased expression of proliferation marker Ki-67, especially in the concentration range between 0.1 mM and 0.5 mM. Further investigations demonstrated that treatment with AA led to significantly increased expression of common stem cell markers OCT4, Nanog, and Sox2. The most potent proliferative and expressional effects of AA were observed in the concentration of 0.1 mM. CONCLUSIONS: AA might be a novel and potent growth promoter of human dental cells. Increasing the properties of human dental pulp cells and the cells of the apical papilla using AA could be a useful factor for further clinical developments of regenerative endodontic procedures.

A prospective, randomized clinical trial of a two-step self-etching vs two-step etch-and-rinse adhesive and SEM margin analysis: four-year results.

PURPOSE: The aim of this blinded, randomized, prospective long-term study was to evaluate the clinical performance of the two-step self-etching adhesive AdheSE (AS, Ivoclar Vivadent) compared to the etch-and-rinse adhesive system Excite (EX, Ivoclar Vivadent) in combination with the hybrid resin composite Tetric Ceram HB (Ivoclar Vivadent) for Class I and II restorations. MATERIALS AND METHODS: In accordance with a split mouth design, 50 patients received 100 restorations in premolars and molars. The restorations were assigned at random to the self-etching (AS) or the etch-and-rinse (EX) group. Each restoration was scored according to the modified Ryge criteria at baseline and after 6, 12, 24 and 48 months. Epoxy resin replicas of 60 restorations were made at each observation period for an additional SEM analysis of the occlusal margins. RESULTS: After 4 years, 60 of 100 restorations could be evaluated. The cumulative survival rate for group EX was 100% and for group AS 96.7%. One restoration in group AS had failed due to marginal gap formation. For the criterion marginal adaption in group AS, significantly more bravo ratings (30%) were observed after 4 years compared to group EX (6.7%) (p < 0.05; Mann-Whitney U-test). The results of the SEM margin analysis revealed no significant differences between groups AS and EX (Mann-Whitney U-test; p > 0.05). CONCLUSION: Both adhesive systems performed satisfactorily over the four-year observation period. A significant deterioration over time was found for the criterion marginal adaption in AdheSE.

The influence of application of different desensitisers on root dentine demineralisation in situ.

AIM: To evaluate the influence of three desensitisers on root caries demineralisation in situ. METHODS: The root surfaces of 36 freshly extracted human molars were used to prepare root dentine specimens. These specimens were distributed among the following groups: A: Admira Protect, V: VivaSens, H: Hyposen, C: control group, untreated. Two dentine specimens of each group were inserted into two buccal aspects of intraoral mandibular appliances. The appliances were worn by nine persons for five weeks, day and night. One side was brushed daily with a toothpaste. On the other side, plaque was allowed to grow. Individual oral hygiene techniques were performed without any fluorides. After the in situ period, two slabs were ground. The depth of the demineralised areas was determined using a polarised light microscope. RESULTS: ANOVA revealed significant differences between brushed and non-brushed specimens. Lesion depths in the brushed group were significantly decreased (p < 0.05, Tukey's test). CONCLUSIONS: Within the limitations of an in situ study it can be concluded that the demineralisation of the root surface can be hampered by application of desensitisers under different oral hygiene conditions. The application of clinical proven desensitising agents might have a caries-protective effect on exposed root surfaces.

Efficacy of 8% arginine on dentin hypersensitivity: A multicenter clinical trial in 273 patients over 24 weeks.

OBJECTIVES: To assess the efficacy of 8% arginine containing prophylaxis products over 24 weeks in subjects with dentin hypersensitivity (DH). METHODS: 297 patients with established DH (Schiff score 2, 3) in three European study centers were randomly assigned to either 8% arginine and calcium carbonate in-office prophylaxis paste and the respective toothpaste (test group) or fluoride-free prophylaxis paste and sodium monoflourophosphate toothpaste as a negative control group. Air blast (Schiff Score) and tactile (Visual Analog Scale) sensitivity scores were assessed at baseline (BL_0), after single application of the prophylaxis paste (BL_1) and after 4, 8, and 24 weeks of continuous at-home use of the toothpaste. RESULTS: 273 subjects completed the study. Test and control group presented statistically significant percentage reductions (t-test, p < 0.05) in Schiff Score at BL_1 and at 24 weeks relative to BL_0 (difference in %; test group: -23.6, -44.9, control group: -8.8, -32.7). The pooled Schiff Score for the two evaluated teeth yielded a significantly greater alleviation of DH in the test group than in the control group at all evaluation appointments (Ancova, p < 0.05; difference in %: 15.3, 7.4, 10.6, 17.2). CONCLUSIONS: A significant relief of DH was demonstrated after application of the 8% arginine prophylaxis products over 24 weeks compared to a negative control. CLINICAL SIGNIFICANCE: Whilst DH is influencing patients' eating, drinking and tooth brushing habits as well as social life interactions it is important that clinicians are able to offer evidence based immediate and long-lasting treatment methods in order to manage their patients' discomfort.

Effects of the desensitizing agents Gluma and Hyposen on the tensile bond strength of dentin adhesives.

PURPOSE: To evaluate the influence of two desensitizers (Gluma Desensitizer and Hyposen) on the tensile bond strength of three different dentin adhesives. METHODS: 90 freshly extracted third molars were specially prepared to allow simulation of dentin perfusion. The specimens were divided at random into nine groups: Group AC: Clearfil New Bond/Clearfil Core; Group AX: Xeno III/Tetric Flow; Group AA: AdheSE/Tetric Flow; Group BC: Gluma/Clearfil New Bond/Clearfil Core; Group BX: Gluma/Xeno III/Tetric Flow; Group BA: Gluma/AdheSE/Tetric Flow; Group CC: Hyposen/Clearfil New Bond/Clearfil Core; Group CX: Hyposen/Xeno III/Tetric Flow; Group CA: Hyposen/AdheSE/Tetric Flow. Tensile bond strength of the above mentioned bonding agents was measured using a universal testing machine. RESULTS: The following tensile bond strengths were obtained (mean values and standard deviations in MPa): Group AC: 11.05 +/- 1.92, Group AX: 6.01 +/- 1.35, Group AA: 8.91 +/- 1.20, Group BC: 10.25 +/- 1.44, Group BX: 7.17 +/- 1.24, Group BA: 10.35 +/- 1.26, group CC: 8.11 +/- 0.70, Group CX: 8.03 +/- 1.20, Group CA: 9.22 +/- 1.75. Statistical analysis showed a significant influence of the variable, dentin bonding agent on tensile bond strength (ANOVA, Tukey's, P < 0.05). Treatment with Hyposen in combination with Clearfil New Bond resulted in significantly lower bond strength values. Gluma had no significant influence on bond strength of the three adhesive systems. Within the limitations of an in vitro investigation it can be concluded that Gluma did not significantly affect the bond strength of any of the adhesive systems tested. Hyposen significantly decreased the bond strength values of Clearfil New Bond.

Influence of different brazing and welding methods on tensile strength and microhardness of orthodontic stainless steel wire.

The aim of this study was to compare the mechanical strength and microhardness of joints made by conventional brazing and tungsten inert gas (TIG) and laser welding. A standardized end-to-end joint configuration of the orthodontic wire material in spring hard quality was used. The joints were made using five different methods: brazing (soldering > 450 degrees C) with universal silver solder, two TIG, and two laser welders. Laser parameters and welding conditions were used according to the manufacturers' guidance. The tensile strengths were measured with a universal testing machine (Zwick 005). The microhardness measurements were carried out with a hardness tester (Zwick 3202). Data were analysed using one-way analysis of variance and Bonferroni's post hoc correction (P < 0.05). In all cases, brazing joints ruptured at low levels of tensile strength (198 +/- 146 MPa). Significant differences (P < 0.001) between brazing and TIG or laser welding were found. The highest means were observed for TIG welding (699-754 MPa). Laser welding showed a significantly lower mean tensile strength (369-520 MPa) compared with TIG welding. Significant differences (P < 0.001) were found between the original orthodontic wire and the mean microhardness at the centre of the welded area. The mean microhardness differed significantly between brazing (1.99 GPa), TIG (2.22-2.39 GPa) and laser welding (2.21-2.68 GPa). For orthodontic purposes, laser and TIG welding are solder-free alternatives to joining metal. TIG welding with a lower investment cost is comparable with laser welding. However, while expensive, the laser technique is a sophisticated and simple method.

Influence of three different sealants on root dentin demineralization in situ.

PURPOSE: To evaluate in situ the onset of initial demineralization in human dentin pretreated either with two different dentin bonding agents or a desensitizer. METHODS: 28 freshly extracted human molars were included in this study. The root surfaces were thoroughly cleaned, thereby removing the cementum. From each tooth four root dentin specimens were prepared. The specimens were distributed among the following experimental groups: C: control group (untreated), S: Syntac Classic, X: Xeno III, and H: Hyposen. For each subject, one dentin specimen of each group was inserted into both buccal aspects of a bilateral intraoral mandibular appliance. The appliances were worn by 14 subjects for 5 weeks day and night. One side was brushed daily with fluoride-containing toothpaste (Aronal) (B). On the other side, plaque was allowed to grow (NB). Individual oral hygiene techniques were performed without any fluorides. During meals, the appliance was stored in 10% sucrose solution. After the in situ period, slabs (150 microm) were ground and studied using polarized light microscopy. RESULTS: For lesion depth, ANOVA revealed significant differences between brushed and unbrushed specimens. In the brushed groups, the following lesion depths were evaluated (mean values and standard deviation in microns): Group B-C: 74.1 (+/- 18.5), Group B-S: 27.6 (+/- 9.6); Group B-X: 28.7 (+/- 9.6), and Group B-H: 34.3 (+/- 20.6). The non-brushed specimens showed following lesion depths: Group NB-C: 101.7 (+/- 23.9), Group NB-S: 59.9 (+/- 13.1), Group NB-X: 52.5 (+/- 12.1), and Group NB-H: 72.9 (+/- 19.9). Compared to the non-brushed groups, lesion depths in the brushed group were significantly decreased (P < 0.05, Tukey's test). The reduction of lesion depths after application of the three agents was significant in both cases (brushed and non-brushed groups). Within the limitations of an in situ study it can be concluded that the demineralization of the root surface can be inhibited by application of dentin adhesives and desensitizers under different oral hygiene conditions.

Apical sealing ability of 2 epoxy resin-based sealers used with root canal obturation techniques based on warm gutta-percha compared to cold lateral condensation.

OBJECTIVE: To evaluate the apical sealing ability of 2 epoxy resin-based root canal sealers used with 2 different warm gutta-percha obturation techniques and cold lateral condensation. METHOD AND MATERIALS: The root canals of 72 freshly extracted single-root incisors were prepared and randomly assigned to 6 experimental groups. Root canal fillings were performed using either cold lateral condensation, warm vertical condensation, or Thermafil obturators with EndoRez or AH Plus as sealer. After root canal filling, the teeth were stored in 5% methylene blue solution for 7 days. Linear dye penetration was measured in bisected specimens by a calibrated investigator using a light microscope. RESULTS: Statistical analysis revealed significantly higher penetration depths in groups where EndoRez was used (P < .05, Tukey test). Regarding the different obturation techniques, the least amount of dye penetration was observed for AH Plus and EndoRez when warm vertical condensation was used. CONCLUSION: The results of this study indicate that the apical sealing ability of EndoRez is not as effective as that of AH Plus. Thermafil obturators and warm vertical condensation achieved seals with low dye penetration depth. The use of these techniques might decrease the risk of apical leakage.

The influence of human plasma used for in vitro dentin perfusion on microtensile bond strength of 5 self-conditioning dentin adhesives.

OBJECTIVE: The aim of this in vitro study was to evaluate the effect of human plasma, compared to physiologic saline, on microtensile bond strengths of 5 self-conditioning dentin adhesives when used as a dentin perfusion medium. METHOD AND MATERIALS: One hundred and fifty extracted human third molars were prepared in a special manner allowing the simulation of intrapulpal pressure and dentin perfusion. The specimens were randomly divided into 10 experimental groups. Five groups were perfused with physiologic saline, while the others were perfused with diluted human plasma, each under constant hydrostatic pressure of 30 cm H2O. One saline group and 1 human plasma group was then assigned to each of the following dentin adhesives: Clearfil SE Bond (Kuraray), Clearfil Protect Bond (Kuraray), Xeno 3 (Dentsply), Futurabond NR (Voco), and iBond (Heraeus Kulzer). The microtensile bond strength for each group was evaluated using a Zwick universal testing machine 10 minutes after light curing. RESULTS: Pairwise comparison showed a significant increase of bond strength in all human plasma-perfused subgroups (P < .05, Tukey's test). The influence of the different dentin adhesives was significant (P < .001, analysis of variance). The highest significant values were observed for Futurabond NR and iBond with human plasma (P < .05, closed test procedure). CONCLUSION: The use of human plasma might be a suitable alternative to imitate perfused dentin conditions in testing devices and might eliminate the discrepancy between different in vitro investigations focusing on bond strength of dentin adhesives.

The influence of human plasma used for dentin perfusion on tensile bond strength of different light-curing materials.

PURPOSE: To evaluate the influence of two perfusion solutions, saline and human plasma, on tensile bond strengths of five different light-curing materials in an in vitro investigation. METHODS: 150 human third molars were used. All teeth were prepared in a special manner allowing the simulation of intrapulpal pressure and dentin perfusion. Dentin specimens with a thickness of 3.5 mm were obtained under standardized conditions. The specimens were randomly assigned to 10 experimental groups. Five groups were perfused with physiologic saline while with the other five with human plasma under constant hydrostatic pressure of 30 cm H2O was used for at least 1 hour. Tensile bond strength of the different dentin bonding agents and composite or compomer materials (A: Syntac/Tetric, B: Prime & Bond NT/Spectrum TPH, C: Solobond Plus/Arabesk, D: Compoglass SCA/Compoglass, E: Dyract PSA/Dyract) was evaluated using an Zwick Universal testing machine 10 minutes after light-curing. RESULTS: Pairwise comparison showed a significant increase of bond strengths in all human plasma perfused subgroups (P< 0.05; Wilcoxon). The influence of the different dentin adhesives was significant (P< 0.001; ANOVA). The significantly highest values were observed for the composite groups Syntac/Tetric and Solobond Plus/Arabesk (P< 0.05; closed test procedure). The compomer Group D (Compoglass SCA/Compoglass) showed significantly decreased values compared to all other groups (P< 0.05; closed test procedure). Within the limitations of an in vitro study, it can be concluded that the use of human plasma might result in higher tensile bond strength compared to saline.

Short-term retentive values of zirconium oxide posts cemented with glass ionomer and resin cement: an in vitro study and a case report.

OBJECTIVE: This paper presents the results of an investigation focusing on the retention of all-ceramic posts. The aim of the study was to evaluate the influence of two luting agents--a glass-ionomer cement (Ketac Cem) and a resin cement (Panavia F)--on the retention of a prefabricated ceramic post (Cerapost) after different pretreatment techniques in vitro. METHOD AND MATERIALS: Forty freshly extracted incisors and canines were treated endodontically. The root canals were filled with laterally condensed gutta-percha and sealer. The teeth were assigned to 1 of 4 groups, each containing 10 specimens: sandblasted/nonsandblasted post cemented with glass-ionomer cement and sandblasted/nonsandblasted post cemented with resin cement. Tensile tests were carried out. The specimens were also quantitatively analyzed under a scanning electron microscope. RESULTS: The retentive strengths of posts, sandblasted and nonsandblasted, and cemented with Panavia F resin cement, were significantly increased as compared to those cemented with Ketac Cem. CONCLUSION: Both the luting agent and the post-surface pretreatment had a significant influence on the retention of the ceramic post.

The effect of different desensitizing agents on initial demineralization of human root dentin.

OBJECTIVES: The aim of this study was to determine the caries-protective effect of 3 different desensitizing agents (Seal & Protect 2.0, D/Sense 2, and Gluma Desensitizer) on root dentin in vitro. METHOD AND MATERIALS: The root surfaces of 60 freshly extracted, caries-free human molars were used. After removing the cementum, the teeth were coated with an acid-resistant nail varnish, exposing 2 rectangular windows of 2 X 3 mm each on the root surface. One window served as an untreated control, and the other window was treated with 1 of the desensitizing agents. The specimens were randomly distributed among the following experimental groups: group A, D/Sense 2; group B, Seal & Protect 2.0; and group C, Gluma Desensitizer. Subsequently, all specimens were demineralized for 14 days with acidified gel (HEC, pH 4.8, 37 degrees C). Two dentinal slabs were cut from each window. The slabs were ground to a thickness of 80 microm and immersed in water. The demineralization depth was determined using a polarized light microscope. RESULTS: The nontreated control specimens showed lesions with a mean depth of 84.9 microm (+/- 6.0). In the specimens treated with the desensitizing agents, lesion depth was generally significantly reduced. Statistical analysis revealed significantly lower values for the specimens in group B in comparison with the others. CONCLUSION: Within the limitations of an in vitro investigation, it can be concluded that the demineralization of the root surface can be hampered by applying the desensitizing agents tested.

Tensile bond strength of different adhesive systems between bone and composite compared: an in vitro study.

INTRODUCTION: The aim was to compare tensile bond strength of three dentine adhesive systems (Excite, Clearfil New Bond, Etch & Prime 3.0) and two cyanoacrylate adhesives (Cyano Veneer, Histoacryl) to animal bone in vitro. MATERIAL AND METHODS: Specimens from five porcine mandibles (diameter 9 mm) with a total thickness of 4mm (+/-0.5mm) and a cortical layer of 1.5mm (+/-0.2mm) were prepared using trephine burs under constant water cooling and under standardized conditions. They were assigned to five experimental groups. Tensile bond strength of five different adhesive agents (Clearfil New Bond, Etch & Prime 3.0, Excite, Histoacryl and Cyano Veneer was measured 15 min after application and after light curing of a composite material (Tetric Ceram, colour A2) added thereupon using a universal testing machine. Qualitative control was performed by scanning electron microscopy, while examining loaded and unloaded specimens. RESULTS: The measured tensile bond strength was as follows: Clearfil New Bond 8.00 MPa (+/-1.36 MPa), Etch & Prime 3.0 4.05 MPa (+/-1.52 MPa), Excite 2.96 MPa (+/-1.34 MPa), Histoacryl 5.22 MPa (+/-2.00 MPa), Cyano Veneer 4.56 MPa (+/-0.76 MPa). Clearfil New Bond showed significantly higher bond strength than the other four adhesives. Scanning electron microscopy analysis of unloaded specimens showed mixed modes of fracture. As regards the loaded specimens, no tag formation as known for dentine was found. CONCLUSION: Within the limitations of an in vitro investigation it can be concluded that dentine adhesive systems might be useful for bone bonding. Tensile bond strength of the dentine adhesive systems tested on bone is comparable to that evaluated for dentine in earlier investigations.