Retained primary teeth in STAT3 hyper-IgE syndrome: early intervention in childhood is essential.

BACKGROUND: STAT3 hyper-IgE syndrome (STAT3-HIES) is a rare primary immunodeficiency that clinically overlaps with atopic dermatitis. In addition to eczema, elevated serum-IgE, and recurrent infections, STAT3-HIES patients suffer from characteristic facies, midline defects, and retained primary teeth. To optimize dental management we assessed the development of dentition and the long-term outcomes of dental treatment in 13 molecularly defined STAT3-HIES patients using questionnaires, radiographs, and dental investigations. RESULTS: Primary tooth eruption was unremarkable in all STAT3-HIES patients evaluated. Primary tooth exfoliation and permanent tooth eruption was delayed in 83% of patients due to unresorbed tooth roots. A complex orthodontic treatment was needed for one patient receiving delayed extraction of primary molars and canines. Permanent teeth erupted spontaneously in all patients receiving primary teeth extraction of retained primary teeth during average physiologic exfoliation time. CONCLUSIONS: The association of STAT3-HIES with retained primary teeth is important knowledge for dentists and physicians as timely extraction of retained primary teeth prevents dental complications. To enable spontaneous eruption of permanent teeth in children with STAT3-HIES, we recommend extracting retained primary incisors when the patient is not older than 9 years of age and retained primary canines and molars when the patient is not older than 13 years of age, after having confirmed the presence of the permanent successor teeth by radiograph.

Clinical association between chronic periodontitis and the leukocyte extravasation inhibitors developmental endothelial locus-1 and pentraxin-3.

This clinical study aimed to determine whether periodontal disease is associated with expression of developmental endothelial locus-1 (Del-1) and pentraxin-3 (PTX-3), endogenous inhibitors of leukocyte extravasation in humans. Expression of DEL1, PTX3, interleukin-17A (IL17A), and lymphocyte function-associated antigen-1 (LFA1) was determined, using RT-PCR and melting curve analysis, in biopsies of gingival tissues from 95 patients: 42 with moderate periodontitis; 40 with severe periodontitis; and 13 healthy controls. Relative expression of DEL1 and PTX3 was statistically significantly weaker in patients with periodontitis than in the control subjects. On the contrary, both IL17A and LFA1 showed statistically significant stronger expression in patients with periodontitis than in healthy controls. Correlation analysis, performed using Spearman's test, showed that expression of DEL1 was statistically significantly linked to periodontitis (ρ = -0.103) and to age (ρ = -0.134), but not to the gender of the patient, and that expression of PTX3 was significantly correlated with periodontitis (ρ = -0.354). Expression of neutrophil extravasation inhibitors DEL1 and PTX3 show significant, but weak, association with the clinical manifestation of chronic periodontitis.

Efficacy of four preventive measures against enamel demineralization at the bracket periphery-comparison of microhardness and confocal laser microscopy analysis.

OBJECTIVES: The aim of this in-vitro study was to investigate the efficacy of four preventive measures against enamel demineralization and to compare the suitability of microhardness (MH) measurements and confocal laser microscopy (CLSM). MATERIALS AND METHODS: A total of 80 teeth were randomly allocated into four groups. The effect against demineralization of two coating materials (group 1: resin-modified glass ionomer (RMGI) cement varnish (ClinproXT); group 2: composite sealant (ProSeal)) and that of two types of bracket-bonding material (group 3: amorphous calcium phosphate (ACP) composite (AegisOrtho); group 4: RMGI (FujiOrthoLC)) was compared after pH-cycling by MH and CLSM. Measurements were made at the edge of the coating/bracket as well as at 50, 100, 200, and 400 µm distance. The data were converted into values of mineralization (Vol%) and analyzed by parametric (ANOVA and Tukey's post hoc) or non-parametric (Kruskal-Wallis and Games-Howell post hoc) tests. RESULTS: ClinproXT and ProSeal were proved to protect the bracket periphery. However, the area next to them showed demineralizations. The mean area of lesion (CLSM-data) was significantly different between the groups (p < 0.0001). The smallest lesions were revealed for the RMGI-based materials. MH identified only for group 4 a significant difference between the area next to the bracket base and that at 200 and 400 µm distance. CONCLUSION: There was nearly no lesion under both coatings. A stagnation of demineralization was identified particularly for the RMGI. ProSeal showed an inferior protection of the untreated enamel. MH and CLSM analysis were suitable to detect subsurface lesions. CLINICAL RELEVANCE: A diverse efficacy of materials against enamel demineralization at bracket periphery has to be noticed.

Evaluation of the effect of bracket-periphery treatment on prevention of enamel demineralization by consecutive µCT scans.

OBJECTIVES: The aim of this study was to assess the effect of two sealants and two varnishes on the prevention of enamel demineralization, as well as the effect of inattentive surplus enamel-etching by a self-etching primer (SEP). MATERIALS AND METHODS: The sealants ProSeal and Clinpro and the varnishes Protecto and FluorProtector were investigated. For inattentive surplus enamel-etching, Transbond Plus SEP was used. The teeth (N = 75) underwent a pH-cycling for 4 weeks and were examined by weekly consecutive µCT scans (t1-t4) to determine mineral loss (ΔZ Equivalent) and lesion depth (Ld). At t4, we also assessed the fluorescence change (ΔF). RESULTS: For ProSeal, no lesions could be detected. In contrast, we found isolated lesions in the area treated with Clinpro. Teeth with inattentive surplus enamel-etching showed always a higher ΔZ Eqivalent. However, this was not statistically significantly different compared to the teeth treated with the varnishes. The adjacent untreated enamel (except the SEP-treated teeth) always showed significantly more demineralization than any of the treated areas. The ΔF partially confirmed these results. CONCLUSION: No lesions were shown in the area of application of ProSeal. The other materials did not sufficiently protect the enamel; however, a protective effect of all materials was obvious when comparing the bracket-periphery with the adjacent untreated enamel. Additionally, the area of SEP application showed almost always a significantly less demineralization in comparison to that found on the adjacent untreated enamel. CLINICAL RELEVANCE: The bracket-periphery was not always sufficiently protected. The adjacent untreated enamel did not benefit from the bracket-periphery treatment.

Do bonding agents protect the bracket-periphery?--Evaluation by consecutive µCT scans and fluorescence measurements.

OBJECTIVES: The aim of this in vitro study was to consecutively determine the effect of three bonding agents on the prevention of enamel demineralisation at the bracket-periphery and to compare the suitability of micro-computed tomography (µCT) scans and quantitative light-induced fluorescence (QLF) to detect changes within subsurface lesions. MATERIALS AND METHODS: The effect of a resin-modified glass ionomer cement (RMGI) (Fuji Ortho LC), a compomer (Assure) and a composite (Transbond XT) on the prevention of enamel demineralisation at the bracket-periphery was examined. After 7, 14, 21 and 28 days of pH cycling, the teeth (N = 45) were examined by consecutive µCT scans and by using a customised QLF set-up. RESULTS: Particularly for the RMGI and for the compomer, the QLF and µCT scans showed that the formation and the body of the lesion were not precisely located at the enamel next to the bracket margin. There was an area that was almost protected. The progression of demineralisation was decreased for the RMGI and the compomer-treated teeth. CONCLUSION: For bonding orthodontic brackets, the RMGI and compomer were comparably able to decrease the progression of white spot lesions (WSL), although the RMGI showed marginally superior protection. Both methods (QLF and µCT scans) were suitable for investigating the longitudinal fluoride effects on WSL, though these effects were more accurately described by mineral (fluorescence) loss or volume changes than by lesion depth. CLINICAL RELEVANCE: The progression of WSL at the bracket-periphery could be altered by using fluoride-releasing bonding agents for bracket application. This approach represents a minimally invasive preventive measure.

Is there a need for orthodontic plaque indices?--diagnostic accuracy of four plaque indices.

OBJECTIVES: The aim of this study was to assess the diagnostic performance and accuracy of four plaque indices for orthodontic patients. MATERIALS AND METHODS: The plaque accumulation of 140 maxillary incisors with bonded brackets was recorded using intra-oral photographs and assessed using four different plaque indices: the orthodontic plaque (OP) index, the modified orthodontic plaque (MOP) index, the Quigley and Hein (QHP) index and the modified Navy plaque (MNP) index. The assessment was performed twice within a time interval of 4 weeks by four different examiner groups: orthodontists, dentists, students and orthodontic assistants. RESULTS: No significant differences were detected for the OP and MOP indices among the examiner groups. A significant difference was found for the QHP and MNP indices. The inter- and intra-examiner reliability of the OP and MOP indices was good. In contrast, the reliability for the QHP and MNP indices was moderate to poor with few exceptions. The discrimination performance of the OP and MOP indices was excellent. The sum of the sensitivity and specificity was generally lower for the QHP and MNP indices compared with the OP and MOP indices. CONCLUSION: OP and MOP indices showed good performance. The QHP and MNP indices are not appropriate for orthodontic purposes. CLINICAL RELEVANCE: Traditional plaque indices reflect the typical pattern of plaque accumulation for patients without multi-bracket appliances. The performance of these indices for orthodontic patients has never been investigated. Orthodontic plaque indices that focus on the surface along the gingival margin and areas around the bracket exhibit higher diagnostic performance and accuracy compared with traditional indices.

Self-etch adhesives for the bonding of orthodontic brackets: faster, stronger, safer?

OBJECTIVES: This study aimed to evaluate the performance of accelerating procedures for bonding of orthodontic brackets in vitro by comparing different adhesives (etch-and-rinse, self-etch) and polymerization procedures (curing devices, time). The performance was characterized by three parameters: (1) the bond strength achieved, (2) the incidence of enamel damage, and (3) the extent of residual composite on the tooth. MATERIALS AND METHODS: Bracket bonding was performed on 500 extracted human teeth after application of either an etch-and-rinse adhesive or a one-step self-etch adhesive. Two different two-component self-etch adhesives (Clearfil SE and Transbond Plus) and two single-component self-etch adhesives (Ideal and iBond) were investigated after using different polymerization procedures (light-emitting diode for 10 or 20 s or plasma arc curing device for 3 or 6 s). The bond strength, incidence of enamel damage, and extent of residual composite on the tooth were measured. RESULTS: Single-component self-etch adhesives gave the lowest bond strengths. No significant difference in bond strength could be detected between the two-component self-etch adhesives and the etch-and-rinse method. There was a 70.3% risk for enamel damage at bond strengths above 12 MPa, but only 5% risk below 12 MPa and no risk below 8.2 MPa. The risk of enamel damage increased by an odds ratio increment of 1.3 for each additional MPa above 8.2 MPa. CONCLUSION: Single-component self-etch adhesives showed the lowest bond strengths, caused limited enamel damage, and generally left less residual composite on the tooth. CLINICAL RELEVANCE: The nature of the adhesive greatly influences the resultant bond strength, the risk of enamel damage, and the extent of residual composite on the teeth.

Autotransplantation and surgical uprighting of impacted or retained teeth: A retrospective clinical study and evaluation of patient satisfaction.

OBJECTIVES: This retrospective clinical study aimed to determine the success rate of autotransplanted impacted or retained teeth along with a patient satisfaction survey and to analyze the influence of relevant clinical and radiographic parameters. SUBJECTS AND METHODS: Fifty-seven teeth (37 canines, 10 molars, seven premolars, three incisors) in 45 patients (median 15 years) were evaluated over a mean of 1.6 years. The success criteria were pocket probing depth ≤3.5 mm, mobility grade ≤ II, Periotest ≤30 and complete alveolar bone healing. The influencing parameters were oral hygiene, smoking, periodontal screening index, occlusal/proximal contacts, horizontal position, dental age, pulp obliteration and degree of displacement. Furthermore, bone height was measured. RESULTS: The overall success rate was 74%, along with a high patient satisfaction. The survival rate was 96% after a mean follow-up of 1.6 years. The favorable factors were proper oral hygiene, non-smoking, good general periodontal condition, proximal contacts and pulp obliteration. An increase in or maintenance of bone level was found in 96%. CONCLUSIONS: Autotransplantation of impacted or retained teeth is an appropriate treatment, if orthodontic alignment has failed, especially in growing patients.

Does a reduction of polymerization time and bonding steps affect the bond strength of brackets?

High bond strengths are required in order to avoid bracket failure during treatment while brackets should be removable. In addition, chair time should be kept at a minimum. Therefore, the aim of this study was to investigate any differences in bracket's bond strength to enamel by reducing the polymerization time and the steps of bonding procedure. Five hundred teeth were randomly allocated into 20 groups. The groups were established considering the investigated curing units (quartz-tungsten-halogen (QTH) and light-emitting diode (LED), each with two different polymerization times) and the used bonding agents (Clearfil SE Bond, Transbond Plus, Ideal1, iBond, and Transbond XT Primer following acid etching). The brackets were debonded using a shear-peel load and used to calculate the bond strength. The location of adhesive failure was registered by using the modified adhesive remnant index (ARI). The influence of the parameters curing unit, curing time, and bonding agent as well as their interaction products on bond strength showed that the bonding agent influenced the bond strength most followed by curing time. The parameter curing unit as well as all the generated interaction products of it showed a lower impact. Regarding the ARI, the bonding agent exhibited also the highest influence. Using a LED resulted in comparable bond strengths as the QTH curing device also at shorter exposure times. Additionally, the two-component self-etching primers showed similar bond strengths compared to the acid-etching method. Chair time can be reduced by using two-component self-etching primers and LED without decrease of bond strength.

Long-term effectiveness of four pulpotomy techniques: 3-year randomised controlled trial.

A pulpotomy is the therapy for management of pulp exposures due to caries in symptom-free primary molars. The aim was to longitudinally compare the relative effectiveness of the Er:YAG laser, calcium hydroxide and ferric sulphate techniques with dilute formocresol in retaining symptom-free molars. Two hundred primary molars in 107 healthy children were included and randomly allocated to one technique. The treated teeth were blindly reevaluated after 6, 12, 18, 24 and 36 months. Descriptive data analysis and logistic regression analysis accounting for multiple observations per patient by generalised estimating equation were used. Additionally, various influences including tooth type, upper and lower jaws, type of anaesthesia, operator and the final restoration on treatment success were evaluated (Wald chi-square test). After 36 months, the following total (considering clinical and clinically symptom-free radiographic failures) and clinical success rates were determined (in percent): Formocresol 72 (92), laser 73 (89), calcium hydroxide 46 (75), ferric sulphate 76 (97). No significant differences were detected between formocresol and any other technique after 36 months. However, the odds ratio of failure appeared to be three times higher for calcium hydroxide than for formocresol. No significant differences in total success rates were seen regarding the aforementioned influencing clinical parameters. The correct diagnosis of the pulpal status, bleeding control and the specific technique are highly important for long-term success of pulpotomies in primary molars. According to the presented long-term data, pulpotomies using ferric sulphate revealed the best treatment outcome among the used techniques, while calcium hydroxide resulted in the lowest success rates after 3 years. Therefore, we can recommend ferric sulphate for easy and successful treatment of primary molars with caries-exposed pulps.

Effectiveness of ozone against periodontal pathogenic microorganisms.

Ozone has been proposed as an adjunct antiseptic in periodontitis therapy. The aim of this study was to investigate the antimicrobial effectiveness of gaseous/aqueous ozone, in comparison with that of the established antiseptic chlorhexidine digluconate (CHX), against periodontal microorganisms. Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, and Parvimonas micra in planktonic or biofilm cultures were exposed, for 1 min, to gaseous ozone, aqueous ozone, CHX, or phosphate-buffered saline (control). None of the agents was able to substantially reduce the A. actinomycetemcomitans count in biofilm cultures. In contrast, P. gingivalis, T. forsythia, and P. micra could be eliminated by 2% CHX or by ozone gas at 53 gm(-3) . Significantly greater antimicrobial effects were observed against planktonic cultures than against biofilm-associated bacteria. The rate of killing was influenced by the species of bacteria, and by the type and concentration of agent. There were no significant differences in the effectiveness of aqueous ozone (20 µg ml(-1) ) or gaseous ozone (≥ 4 gm(-3) ) compared with 2% CHX but they were more effective than 0.2% CHX. Therefore, high-concentrated gaseous and aqueous ozone merit further investigation as antiseptics in periodontitis therapy. A safe system for applying gaseous ozone into the periodontal pocket that avoids inhalation still needs to be developed.

Effect of different bonding agents on prevention of enamel demineralization around orthodontic brackets.

INTRODUCTION: Demineralization around the bracket is an undesired side effect of orthodontic treatment. The aim of this in-vitro study was to evaluate the efficacy of 5 bonding agents to prevent enamel demineralization. Two quantification methods were used. METHODS: Eighty-five extracted teeth were randomly allocated to 5 groups: (1) Transbond Plus SEP and Transbond XT (both, 3M Unitek, Seefeld, Germany), (2) 37% phosphoric acid, Pro Seal (Reliance Orthodontic Products, Itasca, Ill) and Transbond XT, (3) Clearfil Protect Bond (Kuraray Medical, Okayama, Japan) and Transbond XT, (4) 37% phosphoric acid and Light Bond (Reliance Orthodontic Products), and (5) Ortho Conditioner and Fuji Ortho LC (both, GC, Tokyo, Japan). In-vitro caries was created by pH cycling for 30 days. After demineralization, the teeth were scanned with a commercial cone-beam microtomographic system. Then the teeth were examined by polarized light microscopy. RESULTS: The 2 methods of examination showed significant differences among the 5 groups according to lesion depth and mineral loss (P < 0.01). The resin-modified glass ionomer cement (group 5) had the lowest values for lesion depth and mineral loss. CONCLUSIONS: Fuji Ortho LC showed a significantly smaller lesion depth and less mineral loss compared with the other materials. The cone-beam microtomographic system is suitable for evaluation of subsurface lesions and has considerable advantages.

Failure rate of brackets bonded with antimicrobial and fluoride-releasing, self-etching primer and the effect on prevention of enamel demineralization.

INTRODUCTION: Our aim in this randomized clinical trial was to compare the failure rates of orthodontic brackets by using 2 self-etching primers (SEPs) (Transbond Plus [3M Unitek, Seefeld, Germany] and Clearfil Protect Bond [Kuraray Medical, Okayama, Japan]) with a split-mouth design. Additionally, the effect of Clearfil Protect Bond was investigated regarding inhibition of plaque accumulation and demineralization. METHODS: A total of 480 brackets were bonded in 24 patients with the SEPs. The observation period was 12 months. One week after bonding and at every third recall, the plaque index and a visual rating of the enamel adjacent to the bracket were assessed at the lateral incisors and the first premolars. Additionally, DIAGNOdent (KaVo, Biberach, Germany) values were measured. RESULTS: Over the investigation time, 26 failures were recorded. Five occurred with the brackets bonded with Transbond Plus, and the rest with Clearfil Protect Bond (P = 0.002). The additionally observed parameters had no significant differences. CONCLUSIONS: The failure rate with Clearfil Protect Bond was significantly higher. For our patients, who had adequate oral hygiene, there was no benefit with regard to plaque accumulation and prevention of demineralization with Clearfil Protect Bond.

Artificial saliva contamination effects on bond strength of self-etching primers.

OBJECTIVE: To test the hypothesis that there is no difference in the bond strength with or without contamination with artificial saliva when using two different self-etching primers (Transbond Plus and iBond) in comparison with a conventional acid-etching method (37% phosphoric acid and Transbond XT) for bonding of orthodontic brackets. MATERIALS AND METHODS: One hundred fifty extracted human premolars were randomly allocated to six different groups, with 25 teeth in each group. Orthodontic metal brackets (APC II, Victory Twin 22 UNIV) were used. For contamination, a saliva replacement (Ptyalin) was applied. After contamination the surface was air-dried for 5 seconds and the bonding procedure continued. The bonded teeth were stored in deionized water at 37 degrees C for 30 days and then thermocycled for 24 hours before debonding with a universal testing machine. The load was recorded at bond failure. The location of adhesive failure was determined under magnification using the adhesive remnant index (ARI). RESULTS: Clinically acceptable bond strengths were found for all primers used in this study. The contamination by saliva significantly decreased the bond strength when using the conventional acid-etching method (t = 0.0001). Self-etching primers were less influenced by saliva contamination. There was no significant difference in the ARI score among the groups (P > .05). CONCLUSIONS: Saliva contamination significantly decreased the bond strength when the conventional acid-etching method was used. The self-etching primers were influenced the least. The bond strengths achieved for the self-etching primers and the conventional etching method after saliva contamination were not significantly different.

Orthodontic attachments and chlorhexidine-containing varnish effects on gingival health.

OBJECTIVE: To compare the severity of clinical inflammation parameters and the level of the inflammatory mediator interleukin (IL)-1beta during orthodontic treatment by using brackets and bands. In addition, the effect of a chlorhexidine-containing varnish was investigated. MATERIALS AND METHODS: This prospective randomized controlled trial included 40 healthy children who required an orthodontic treatment of mild crowding. Either brackets or bands were randomly allocated to the premolars with a split-mouth design. Twenty of the children received a chlorhexidine-containing varnish during the treatment (0, 12, 24 weeks), while the remaining children served as a control group. Prior and until 24 weeks after the insertion, data were recorded regarding the pocket depth (PD), the gingival appearance (gingival index [GI]), and the plaque accumulation (plaque index [PI]). Gingival crevicular fluid was collected as well. A quantitative enzyme-linked immunoassay technique was used to detect differences in IL-1beta. RESULTS: The PDs and the gingival index of teeth with brackets showed significantly lower values in comparison with teeth treated with bands (P = .0001). The IL-1beta levels confirmed these findings. In contrast, the PI showed higher values for the teeth with brackets (P = .0001). The teeth that received a chlorhexidine-containing varnish showed significantly lower values in the follow-ups for most of the evaluated parameters (PD Band, PI Band, PI Bracket, GI Band, GI Bracket; P < .015). CONCLUSION: The clinically observed parameters as well as the IL-1beta levels reflected the higher impact of bands on gingival health. These values showed a significant decrease after application of a chlorhexidine-containing varnish. However, the PI showed higher values for the teeth with brackets.

Linking genetic susceptibility to Crohn's disease with Th17 cell function: IL-22 serum levels are increased in Crohn's disease and correlate with disease activity and IL23R genotype status.

BACKGROUND: We analyzed the influence of Crohn's disease (CD)-associated IL23R gene variants on IL-22 that is expressed in IL-23R+ Th17 cells. METHODS: IL-22 serum levels were measured in 242 CD patients and in 31 healthy controls. Subanalyses included serum levels of IL-6, TNF-alpha, IL-17A, IL-17F, C-reactive protein (CRP), and leukocyte count. In all patients, genotyping for 10 CD-associated IL23R single nucleotide polymorphisms (SNPs) and the 3 main CD-associated CARD15 variants was performed. RESULTS: There was a highly significant increase in IL-22 serum expression in CD patients compared to healthy controls (P = 2.53 x 10(-9)). IL-22 serum levels correlated with disease activity: IL-22 levels in patients with a Crohn's disease activity index (CDAI) >150 were significantly higher than in patients with a CDAI <150 (P = 0.001), while TNF-alpha and IL-6 were not significantly different between these 2 groups. Analyzing the effect of 10 IL23R variants on IL-22 serum levels, we demonstrated that the quotients of mean IL-22 serum levels of carriers of the minor allele to the mean serum IL-22 in wildtype carriers correlated highly with the corresponding CD susceptibility risk for each gene variant (r = 0.807). The IL-22 levels in carriers of CD risk-increasing IL23R variants were significantly higher than in carriers of CD risk-decreasing IL23R variants (P = 0.008). CONCLUSIONS: The Th17 cytokine IL-22 is expressed at high levels in CD and correlates with disease activity, offering a better separation between active and inactive CD than IL-6 and TNF-alpha. IL23R genotypes influence IL-22 serum expression, linking genetic CD susceptibility to Th17 cell function for the first time.

Effect of ozone on oral cells compared with established antimicrobials.

Ozone has been proposed as an alternative antiseptic agent in dentistry based on reports of its antimicrobial effects in both gaseous and aqueous forms. This study investigated whether gaseous ozone (4 x 10(6) microg m(-3)) and aqueous ozone (1.25-20 microg ml(-1)) exert any cytotoxic effects on human oral epithelial (BHY) cells and gingival fibroblast (HGF-1) cells compared with established antiseptics [chlorhexidine digluconate (CHX) 2%, 0.2%; sodium hypochlorite (NaOCl) 5.25%, 2.25%; hydrogen peroxide (H(2)O(2)) 3%], over a time of 1 min, and compared with the antibiotic, metronidazole, over 24 h. Cell counts, metabolic activity, Sp-1 binding, actin levels, and apoptosis were evaluated. Ozone gas was found to have toxic effects on both cell types. Essentially no cytotoxic signs were observed for aqueous ozone. CHX (2%, 0.2%) was highly toxic to BHY cells, and slightly (2%) and non-toxic (0.2%) to HGF-1 cells. NaOCl and H(2)O(2) resulted in markedly reduced cell viability (BHY, HGF-1), whereas metronidazole displayed mild toxicity only to BHY cells. Taken together, aqueous ozone revealed the highest level of biocompatibility of the tested antiseptics.

Investigation of shear-peel bond strength of orthodontic brackets on enamel after using Pro Seal.

AIM: The aim of this investigation was to ascertain whether the use of a fluoride-releasing, light-curing sealant (Pro Seal, Reliance Orthodontic Products, Itasca, IL, USA) results in differences in shear-peel bond strength when teeth are etched via the conventional acid-etching method and with self-etching primers (SEP), respectively. We also examined whether Pro Seal functions as a substitute for the bonding agents recommended by the manufacturers. MATERIAL AND METHODS: To carry out this study, we randomly allocated 300 extracted molars (ISO 11405) into twelve groups (n=25). The brackets used (Victory Series, Twin UBi 0T/0A .022, 3M Unitek, Seefeld, Germany) were bonded using the same layer thickness of adhesive. The teeth were then stored for 24 h in de-ionized water (37 degrees C) and subsequently thermocycled. The brackets were debonded using a universal testing machine with a crosshead speed of 0.5 mm/min. For statistical evaluation we used the one-way analysis of variance (ANOVA [alpha = 0.05]) and the post hoc Tukey test and Weibull analysis. RESULTS: We could establish that the use of Pro Seal does not have a negative influence on shear-peel bond strength. When the compomer Assure was used, Pro Seal even led to an increase in shear-peel bond strength, especially when it was applied using the bonding agent recommended by the manufacturer. The highest Weibull modulus (m) was found for the self-etching primer IDEAL 1 without using Pro Seal (m=6.5) and the lowest for First Step SEP when using Pro Seal (m=2.2). There were also clear differences in characteristic shear-peel bond strength (sigma(0)) within some of the groups investigated. CONCLUSIONS: Although the statistical evaluation showed no significant negative influence on the shear-peel bond strength either when Pro Seal was used in addition, or when that fluoride-releasing, light-curing sealant was substituted for the bonding agent recommended by the manufacturer, the Weibull analysis showed that the use of Pro Seal in combination with SEP resulted in bond strength values that were less reliably reproducible.