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For people with type 1 diabetes, self-management is a necessity. However, self-management can be impeded by aspects of everyday life, which may impact young adults moving to independence. However, it is not yet clear which aspects are most relevant, nor what knowledge gaps remain. An established scoping review methodology was used to select and synthesise the existing literature. Sixteen peer reviewed articles were included for analysis. Type 1 diabetes self-management exists within a disordered space, impeded by aspects of everyday life, while simultaneously impeding daily living. Negative attitudes, concealment, non-adherence, Diabetes Distress, and mental illness were each associated with difficulty in self-management. A cyclical relationship between these characteristics emerged: they are obstacles to self-management yet also result from poor self-management. Young adults were identified as a vulnerable demographic: they tend to perceive type 1 diabetes more negatively and have additional life priorities (e.g., education/work) that lead to suboptimal self-management, including non-adherence behaviours, which can reduce quality of life. Several gaps in the literature were found, notably around psychological experiences, employment, and effective interventions. Few studies involved in-depth exploration of lived experiences. There is a need to develop novel interventions to support self-management of type 1 diabetes that target the obstacles identified here. Furthermore, experiential research into younger adults' experiences of life and work with type 1 diabetes will help fill the knowledge gap for this demographic. • Several factors associated with everyday life are obstacles to self-management of type 1 diabetes. • Little is known about what works for whom in self-management support. • Young adults are a particularly vulnerable demographic, for whom novel interventions for self-management support are needed. [ABSTRACT FROM AUTHOR]

Background: Many countries have recently experienced a rapid increase in the demand for forensic age estimates of unaccompanied minors. Hong Kong is a major tourist and business center where there has been an increase in the number of people intercepted with false travel documents. An accurate estimation of age is only possible when a dataset for age estimation that has been derived from the corresponding ethnic population. Thus, the aim of this study was to develop and validate a Reference Data Set (RDS) for dental age estimation for southern Chinese.Materials and Methods: A total of 2306 subjects were selected from the patient archives of a large dental hospital and the chronological age for each subject was recorded. This age was assigned to each specific stage of dental development for each tooth to create a RDS. To validate this RDS, a further 484 subjects were randomly chosen from the patient archives and their dental age was assessed based on the scores from the RDS. Dental age was estimated using meta-analysis command corresponding to random effects statistical model. Chronological age (CA) and Dental Age (DA) were compared using the paired t-test.Results: The overall difference between the chronological and dental age (CA-DA) was 0.05 years (2.6 weeks) for males and 0.03 years (1.6 weeks) for females. The paired t-test indicated that there was no statistically significant difference between the chronological and dental age (p > 0.05).Conclusion: The validated southern Chinese reference dataset based on dental maturation accurately estimated the chronological age. [ABSTRACT FROM AUTHOR]

Summary Background Pre-registration nursing students throughout the United Kingdom (UK) are required to complete a minimum number of theory hours within the course. Anecdotal evidence suggests that students are required to attend campus for approximately fifty percent of the theory hours. The remaining theory hours are often labelled as ‘study time’ in which students are not required to attend campus. There is a general assumption amongst many academics that all students are prepared and motivated to direct their learning and therefore use this time to study. However some students chose to work during this time and many have dependents. Considering the increasing cost of nurse education combined with the government cuts to student bursaries in England it is timely to review the literature to determine how study time is used within pre-registration nurse education. Objective To present a critical review of the literature pertaining to study time in pre-registration nurse education. Design An integrative review of the literature. Data Sources A search of electronic databases: Cumulative Index to Nursing and Allied Health (CINAHL); Cochrane; Medline; Science Direct; Blackwell Synergy; Electronic Journals Service (EJS); Scopus; Taylor & Francis, Eric and Routledge Wiley was undertaken. Review Methods The inclusion criteria consisted of peer reviewed primary research, discussion papers, unpublished doctoral theses' and editorial papers directly related to the key words and nurse education published in English. Results Twelve papers were included in the review. Analysis of the papers led to the development of two themes: orientation to self-directed learning (SDL) and preparation for SDL. Conclusions The literature demonstrates that pre-registration nursing students lack the necessary skills for SDL. There is a lack of research on how study time is used within pre-registration nurse education. This calls for empirical research to fully explore how nursing students and lecturers perceive study time within pre-registration nursing curricula. [ABSTRACT FROM AUTHOR]

Introduction: Treatment of impacted maxillary canines frequently requires surgical intervention, which can involve substantial complications. Thus, it is desirable to identify a reliable method for the early diagnosis of canine displacement. In this study, we sought to determine whether impaction of a maxillary canine can be predicted using measurements made on a panoramic radiograph. Methods: This retrospective study was conducted at a dental hospital in Hong Kong with panoramic radiographs. Geometric measurements were made on 384 panoramic radiographs of patients with a unilaterally impacted maxillary canine (group I) to characterize its presentation and compare them with the unaffected antimere (group II). Results: There was a clinically discernible difference of 4 mm at the age of 8 years and beyond between the mean distance of the tip of the impacted canine (group I) and that of the antimere (group II) from the occlusal plane (P <0.05). Furthermore, there was a statistically significant difference at the age of 9 years and beyond between the 2 groups according to the position in different sectors and according to the mean angle made with the midline (P <0.05). Conclusions: Diagnosis of maxillary canine impaction is possible at 8 years of age by using geometric measurements on panoramic radiographs. [ABSTRACT FROM AUTHOR]

Purpose: Impaction of a maxillary canine is a frequent occurrence and often requires a multidisciplinary approach for proper management. The success of different treatment modalities used to treat impacted maxillary canines is largely based on clinical experience and anecdotal evidence, with only a few studies published in the literature on the subject. Hence the aim of this study was to determine the success rate and the difference in duration of the various treatment modalities for impacted maxillary canines. Materials and Methods: Four hundred forty-eight southern Chinese children and adolescents who were provided treatment for their impacted maxillary canines between February 1982 and February 2009 were included in the analysis. Because this was a retrospective study and did not involve human subjects, it was exempt from requiring review board approval. Results: The most commonly performed treatment for correction of an impacted maxillary canine was surgical removal of the impacted tooth. In cases where surgical exposure of the impacted canine followed by bonding an attachment was performed, the mean time required for the impacted canine to erupt postoperatively through the soft tissue was 12.6 months (SD, 7.5 months). Conclusions: The success rate of all forms of treatment modalities used to treat impacted maxillary canines was 90.9%, which was commensurate with figures reported at other centers. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: This study investigated the use of 3.8% silver diamine fluoride (Ag[NH3]2F) as an antibacterial agent against Enterococcus faecalis biofilms and its ability to penetrate dentinal tubules by the formation of silver salts. Methods: Biofims were generated on membrane filter discs and subjected to 15-minute and 60-minute exposure times with 3.8% Ag(NH3)2F, saturated Ca(OH)2, 5.25% NaOCl (negative control), and 0.9% NaCl (positive control). Cleaned and shaped radicular dentin were applied with Ag(NH3)2F for 24, 48, and 72 hours. The presence of silver salts on the dentin surface was examined using low-pressure scanning electron microscopy. Results: Both NaOCl and Ag(NH3)2F were effective against E. faecalis biofilms, with no significant difference in reduction of microorganisms for both exposure times. Silver deposits were present on 66.5% of the radicular dentin surfaces after 72-hour application of Ag(NH3)2F as simulated interappointment dressings. Penetration of the silver deposits was observed at most 40 μm into dentinal tubules after smear layer removal. Conclusion: Ag(NH3)2F has potential to be used as an antimicrobial root canal irrigant or interappointment dressing, especially in locations in which potential browning/blackening of dentin by metallic silver is not a major concern. [Copyright &y& Elsevier]

Abstract: Introduction: This study evaluated the extent of chlorhexidine release from experimental chlorhexidine-containing polymethyl methacrylate (PMMA)-based root canal sealers prepared from a methacrylate-based sealer (SuperBond Sealer, Sun Medical Co Ltd, Shiga, Japan) and to examine its antimicrobial effect against Enterococcus faecalis using the direct contact test. Methods: Chlorhexidine diacetate powder was mixed with PMMA powder of SuperBond Sealer to obtain chlorhexidine concentrations of 1 wt%, 2 wt%, and 3 wt%, respectively. PMMA disks were fabricated by self-curing the experimental PMMA powder and pure SuperBond sealer (control) and immersing them in distilled water at 37 °C for 12 weeks. Chlorhexidine release was analyzed by high-performance liquid chromatography. The direct contact test was performed on wells of 96-well plates coated with the respective experimental root canal sealers (n = 6). Bacterial suspensions were placed directly on the sealers that were aged for 12 weeks. Results: The cumulative chlorhexidine release after 12 weeks of water immersion was largely dependent on the amount of chlorhexidine powder that was initially incorporated into the PMMA-based sealer. Kruskal-Wallis test revealed that chlorhexidine concentration had a significant effect on the cumulative release (p = 0.0005). Experimental sealers with the incorporation of 2 wt% and 3 wt% chlorhexidine exhibited sustained antimicrobial effect for at least 4 weeks and 8 weeks. Conclusion: The incorporation of 2wt% and 3wt% chlorhexidine in the PMMA-based sealer had a long lasing antimicrobial effect against Enterococcus faecalis as a result of the turbidimetric determination of bacterial growth. [Copyright &y& Elsevier]

Abstract: The susceptibility of Resilon (Pentron Clinical Technologies, Wallingford, CT) to biotic biodegradation by two hydrolases, lipase PS and cholesterol esterase, was investigated with a turbidimetric approach by measuring the optical density reductions in aqueous emulsions containing dissolved, filtered, surfactant-stabilized polymeric components of Resilon. Polycaprolactone, the major polymeric component of Resilon, was also examined in a similar manner using equivalent or a four-fold increase in enzyme concentration. Optical density time plots were characterized by an initially linear steep reduction in optical density, from which the reaction rates were derived. For both enzymes, the rates of hydrolysis for Resilon were much faster than those of polycaprolactone at 1× or even 4× enzyme concentration. Field-emission scanning electron microscopy of air-dried Resilon and polycaprolactone emulsions revealed the presence of spherical polymer droplets that appeared deformed, pitted, or much reduced in dimensions after enzymatic hydrolysis. [Copyright &y& Elsevier]

Abstract: Potential intrinsic tetracycline staining of intraradicular dentin has been observed when BioPure MTAD was employed as the final irrigant after initial rinsing with NaOCl. This study examined the effect of NaOCl-MTAD interaction on the antimicrobial substantivity of MTAD in dentin. Dentin cores previously irrigated with either MTAD, or in conjunction with 1.3% NaOCl as an initial irrigant were placed on blood agar plates inoculated with Escherichia faecalis at 105 cfu/ml. Dentin cores irrigated with 1.3% NaOCl only, and autoclaved dentin disks were used as the respective positive and negative controls. After anaerobic incubation, the mean diameter of bacterial inhibition zones formed around the MTAD group was significantly larger than the NaOCl/MTAD group, which, in turn, was not significantly different from the NaOCl positive control. Oxidation of MTAD by NaOCl resulted in the partial loss of antimicrobial substantivity in a manner similar to the peroxidation of tetracycline by reactive oxygen species. [Copyright &y& Elsevier]

Abstract: This study examined the effects of copolymer hydrophilicity and temperature on water sorption and solubility characteristics of five copolymer blends of increasing degree of hydrophilicity using gravimetric measurements. Six resin disks (15mm in diameter×1mm in thickness) were prepared from each copolymer blend and were stored in deionised water at 23, 37 and 55°C. Water sorption and solubility of the resin disks were measured before and after water immersion and desiccation. Multiple regression analysis of water sorption was performed on two independent variables, copolymer hydrophilicity and temperature. Maximum water sorption increased significantly with Hoy''s total cohesive energy density (), Hoy''s solubility parameter for polar forces () and hydrogen bonding (), but was not influenced by temperature. However, a significant positive relationship was observed between diffusion coefficients (obtained using Fick''s law of diffusion) and temperature. The water absorption activation energy was 10kJ/mol for the most hydrophilic copolymer blend R5 and 35–51kJ/mol for copolymer blends R1–R4. The positive relationship between maximum water uptake and copolymer hydrophilicity suggests that water molecules diffuse through the polymer matrices by binding successively to the polar sites via hydrogen bonding. Such water sorption may determine the durability of resin–dentine bonds. [Copyright &y& Elsevier]

Abstract: The structure of mechanically instrumented intraradicular dentin after irrigation with NaOCl as the initial rinse and BioPure MTAD as the final rinse were examined from the coronal, middle, and apical parts of root canal walls using transmission electron microscopy. Sterile distilled water and EDTA as final rinses were employed as the respective positive and negative controls under the same experimental conditions. There were 2 to 5 μm thick smear layers produced on mechanically instrumented root canal walls that were completely removed by EDTA and BioPure MTAD under agitation. Both irrigants created a zone of demineralized collagen matrices in eroded dentin and around the dentinal tubules, with the mildly acidic BioPure MTAD being more aggressive than EDTA. These demineralized dentin zones create the opportunity for dentin hybridization by infiltration of hydrophilic adhesives/sealers. However, the potential consequences of compaction of hydrophobic sealers against air-dried, collapsed collagen matrices, and hydrolytic degradation of incompletely infiltrated matrices remain unresolved. [Copyright &y& Elsevier]

Abstract: Polycaprolactone is susceptible to enzymatic biodegradation via ester bond cleavage. This study examined the susceptibility of Resilon, a polycaprolactone-based root filling material to enzymatic hydrolysis. Resilon, gutta-percha, and polycaprolactone disks, prepared by compression molding, were incubated in phosphate-buffered saline, lipase PS or cholesterol esterase at 37°C for 96 h. They were retrieved at different time intervals for gravimetric analysis and scanning electron microscopy. The materials exhibited slight weight gains when incubated in phosphate-buffered saline that can be attributed to water sorption. Gutta-percha showed similar weight gains in the two enzymes. Conversely, Resilon and polycaprolactone exhibited extensive surface thinning and weight losses after incubation in lipase PS and cholesterol esterase. Glass filler particles in Resilon were exposed following surface dissolution of the polymer matrix, creating rough surface topography. Biodegradation of Resilon by bacterial and salivary enzymes warrants further investigation of their activities using cultures of endodontically relevant microbes and human saliva extracts. [Copyright &y& Elsevier]

Abstract: Polycaprolactone, a thermoplastic aliphatic polyester, is reportedly susceptible to both alkaline and enzymatic hydrolyzes. This screening study examined the susceptibility of Resilon, a polycaprolactone-based root filling composite, to alkaline hydrolysis. There were 15-mm diameter disks of Resilon and Obtura gutta-percha prepared by compressive molding and immersed in 20% sodium ethoxide for 20 or 60 min. Control disks were immersed in ethanol for 60 min. These disks were examined using field-emission scanning electron microscopy and energy dispersive X-ray analysis. For Resilon, the surface resinous component was hydrolyzed after 20 min of sodium ethoxide immersion, exposing the spherulitic polymer structure and subsurface glass and bismuth oxychloride fillers. More severe erosion occurred after 60 min of sodium ethoxide treatment. Gutta-percha was unaffected after immersion in sodium ethoxide. As Resilon is susceptible to alkaline hydrolysis, it is possible that enzymatic hydrolysis may occur. Biodegradation of Resilon by bacterial/salivary enzymes and endodontically relevant bacteria warrants further investigation. [Copyright &y& Elsevier]

This systematic review and meta-analysis aimed to evaluate the overall, clinical, and radiographical success rates of alternative pulpotomy medicaments in primary teeth. A systematic search of five databases was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Prospective clinical trials using alternative pulpotomy medicaments in children were included. The outcome measures were overall, clinical, and radiographic success, expressed in percentages and converted to odds ratios. Fifteen articles were included in the meta-analysis. Combined odds ratios for overall, clinical, and radiographic success was 0.55 (95% confidence interval [CI]: 0.12-2.41; P =.42; I2 = 76%), 1.03 (95% CI: 0.57-1.86; P =.92; I2 = 0%), and 0.84 (95% CI: 0.54-1.47; P =.66; I2 = 34%), respectively. The results suggest an inconclusive outcome in the success rate of alternative medicaments. There is insufficient evidence to support the efficacy of alternative pulpotomy medicaments for use in primary teeth. Further robust studies are required before such alternative medicaments should be used in clinical practice. [ABSTRACT FROM AUTHOR]

Abstract: The aetiology of impacted maxillary canines remains obscure. Numerous researchers have focused on identifying specific and non-specific aetiological factors responsible for canine displacement. Currently, the two most popular hypotheses that have gained consensus worldwide are the guidance theory and the genetic theory. However, no single hypotheses, can completely explain the aetiology of impaction of maxillary canines. This retrospective study was used to develop and postulate the aetiology of both buccally and palatally impacted maxillary canines. The study was conducted on a sample of 533 patients for whom the pattern and distribution of the impacted maxillary canines, sex differences, the dental age of the patients, dental anomalies and various geometric measurements which were made on the panoramic radiographs were recorded. Based on these findings, the sequential hypothesis of impaction of the maxillary canine was postulated. The hypothesis states that both buccally and palatally impacted canines have similar aetiological factors leading to their impaction. It is suggested that genetic mechanisms strongly influence the potential of the maxillary canine to be impacted and the guidance from the lateral incisor and the stage of development plays a vital role in determining the ultimate position of the impacted canine. [Copyright &y& Elsevier]

Hypodontia in combination with hyperdontia (hypohyperdontia) is a condition of mixed numeric variation in the human dentition. A comprehensive review on the hypohyperdontia literatures reported prevalence ranges from 0.002% to 3.1%. Our seven cases of hypohyperdontia involved both the maxillary and the mandibular arches. A traditional narrative review is included to describe the prevalence, etiology, and previously reported cases on hypohyperdontia. Furthermore, we opine that comprehensive clinical and radiographic examinations are essential for recognizing such rare dental anomalies. Judicious use of radiographs not only enhances the detection of hypohyperdontia, but also leads to changes in the course of management. [Copyright &y& Elsevier]

Objectives: This was a retrospective study to determine the characteristics and distribution of supernumerary teeth in southern Chinese children. Methods: The study population consisted of 208 children aged from 2 to 16 years. Results: Males were more frequently affected than females in the ratio 3.1:1. Of the 283 supernumerary teeth, 95.0% were located in the premaxilla, 71.5% were conical, 70.7% were unilateral, 29.3% were bilateral, 47.7% were inverted, and 16.9% were erupted. The mean age at the time of diagnosis and removal of the supernumerary teeth was 7.3 ± 2.7 years (the minimum age was 2.1 years) and 8.1± 2.7 years (the minimum age was 4.1 years), respectively. Seventy percent of the children were in the mixed dentition and 81.3% of the supernumeraries were removed under general anesthesia. Conclusion: In accordance with previous studies, the majority of the supernumerary teeth were located in the premaxillary region, were conical shaped, and remained unerupted. [Copyright &y& Elsevier]

Double teeth and talon cusps are rare developmental dental anomalies affecting both primary and permanent dentitions. Talon cusps normally occur on the palatal surface of permanent maxillary incisors, although double teeth are more common in the primary anterior dentition. This paper describes a rare case of fusion of the mandibular permanent incisors with labial and lingual talon cusps. An understanding of these dental anomalies and their associated problems are important to provide prophylactic measures, thereby preventing or minimizing possible complications. [Copyright &y& Elsevier]

Due to the significant increase in the incidence and prevalence of the fetal alcohol syndrome (FAS) in developing and developed nations, it is important that dental professionals recognize this condition. Patients with FAS have orofacial characteristics and various psychological and physical symptoms that may affect a dental treatment plan. This article reviews the prevalence, incidence, alcohol dose response and metabolism, and clinical characteristics of FAS. A case demonstrating moderate signs of the condition is included to illustrate some of the characteristics. [Copyright &y& Elsevier]

Abstract: Dental age assessment is one the most accurate methods for estimating the age of an unknown person. Demirjian''s dataset on a French-Canadian population has been widely tested for its applicability on various ethnic groups including southern Chinese. Following inaccurate results from these studies, investigators are now confronted with using alternate datasets for comparison. Testing the applicability of other reliable datasets which result in accurate findings might limit the need to develop population specific standards. Recently, a Reference Data Set (RDS) similar to the Demirjian was prepared in the United Kingdom (UK) and has been subsequently validated. The advantages of the UK Caucasian RDS includes versatility from including both the maxillary and mandibular dentitions, involvement of a wide age group of subjects for evaluation and the possibility of precise age estimation with the mathematical technique of meta-analysis. The aim of this study was to evaluate the applicability of the United Kingdom Caucasian RDS on southern Chinese subjects. Dental panoramic tomographs (DPT) of 266 subjects (133 males and 133 females) aged 2–21 years that were previously taken for clinical diagnostic purposes were selected and scored by a single calibrated examiner based on Demirjian''s classification of tooth developmental stages (A–H). The ages corresponding to each stage of tooth developmental stage were obtained from the UK dataset. Intra-examiner reproducibility was tested and the Cohen kappa (0.88) showed that the level of agreement was ‘almost perfect’. The estimated dental age was then compared with the chronological age using a paired t-test, with statistical significance set at p <0.01. The results showed that the UK dataset, underestimated the age of southern Chinese subjects by 0.24 years but the results were not statistically significant. In conclusion, the UK Caucasian RDS may not be suitable for estimating the age of southern Chinese subjects and there is a need for an ethnic specific reference dataset for southern Chinese. [Copyright &y& Elsevier]

The impeded/unimpeded eruption rates of the rat incisor have been much studied. The most commonly used optical microscopic method, which has inherent weaknesses, was compared here with an image-analysis method to measure the eruption rate of the mandibular incisor. The study also evaluated the incisal edge as a reference point for the measurement of the unimpeded eruption rate, and the frequency of shortening the mandibular incisor. The image-analysis method was found to be a simple and reliable technique that could replace the optical method. There was no significant difference between the data from the two methods; their κ coefficients were similar at the 0.99 level. It was concluded that shortening the incisor in the measurement of the unimpeded eruption rate should be done at least every 48 h, and that the incisal edge of the shortened incisor can be used as the reference point for that measurement. [Copyright &y& Elsevier]

Eroding coastlines composed of sequences of till, carbon rich peat and sand layers are characteristic of many formerly glaciated coastlines due to the interplay of relative land and sea levels. Dune cliffs cut into these materials represent one of the most sensitive systems to the processes of coastal change. Establishing appropriate scales for the quantification and analysis of change in coastal dune cliffs remains limited by the speed and nature of change, the intensity of environmental processes and the challenges of achieving adequate survey control. This paper presents the results from multi-scale analyses into the behaviour of dune cliffs on the northeast coast, UK, over a 118 year period. Repeat unmanned aerial vehicle (UAV) survey differences have been used to identify and quantify system behaviour, set in context with historic map comparisons. At the landform scale, monthly dune cliff dynamics have been analysed over the course of a year with terrestrial laser scanning (TLS) in order to gain insights into the drivers of contemporary dune cliff behaviour. Finally, pseudo three-dimensional ground-penetrating radar (GPR) data are used to trace subsurface stratigraphy from which the potential extent of stored carbon (in excess of 100 t over 50 m of monitored dune cliff) at risk of release by coastal erosion over the next 50 years can be calculated. The consideration of multi-scale changes over time periods relevant to well-constrained sea level change has revealed a complex combination of failure mechanisms that have resulted in an acceleration in dune cliff recession (particularly over the last decade) and a form change to shallower, divergent profiles. This potential acceleration in contemporary dune cliff response holds significant implications for both coastal management and the contribution of this poorly quantified input to the coastal carbon flux. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effect of adjunctive application of ethanol-wet bonding and chlorhexidine (CHX) with a hydrophobic adhesive on bond durability of fibre posts to intraradicular dentine. Methods: Ninety-six extracted human teeth with a single root and root canal were prepared for post placement after endodontic treatment. The teeth were randomly divided into four groups (n = 24) after etching and rinsing for rewetting: Group 1: water-wet bonding, Group 2: water- wet bonding with CHX, Group 3: ethanol-wet bonding and Group 4: ethanol-wet bonding with CHX. Teeth in Groups 1 and 2 were treated with either distilled water or distilled water with 2% CHX for 60 s; while teeth in Groups 3 and 4 were treated with either 100% ethanol or 100% ethanol with 2% CHX. Two coats of primer, followed by neat resin were applied and light-cured for 40 s. Fibre posts were luted to bonded root dentine using dual-cure resin cement. Bonded roots were subjected to push-out bond strength testing and interfacial nanoleakage evaluation after 24 h, 6 and 12 months of storage. Data were analyzed using 3-way ANOVA (rewetting solutions, time and post space regions) and SNK tests. Results: Groups 3 and 4 showed significantly ( p < 0.05) higher bond strengths and lower nano- leakage than Groups 1 and 2 after 12 months of ageing. Addition of 2% chlorhexidine to ethanol- wet bonding with a hydrophobic adhesive did not further improve the bonding of a fibre post to intraradicular dentine, when compared to ethanol-wet bonding alone after 12 months of ageing. Clinical significance: Ethanol-wet bonding with a hydrophobic adhesive alone could improve the bond durability of fibre post to intraradicular dentine and therefore would increase the success rate of post and core restorations of endodontically treated teeth. [ABSTRACT FROM AUTHOR]

Objectives: To examine the effect of adjunctive application of chlorhexidine (CHX) and ethanol-wet bonding (EWB) on bond durability and nanoleakage of hydrophobic adhesive to sound (SD) and caries-affected dentine (CAD). Methods: Dentine surfaces of molars were etched after caries removal and randomly allocated to four groups (n = 12). In Groups 1 and 2, dentine surfaces were saturated with either 2 ml of 100% ethanol or 2 ml of ethanol with 2% CHX for 60 s. In Groups 3 and 4, dentine surfaces were saturated with either 15 μL of distilled water or 15 μL of distilled water with 2% CHX for 60 s. Two coats of primer, followed by neat resin were applied and lightcured for 40 s. Resin composite build-ups were placed and bonded specimens were sectioned for bond strength testing after 24 h and 12 months' storage in artificial saliva. Bond strength data were analyzed using 3-way ANOVA and SNK tests. Interfacial nanoleakage was evaluated after 24 h and 12 months using a field-emission scanning electron microscopy and data were analyzed using Kruskal-Wallis test. Results: Significant differences were observed for the three factors: ''substrate'' ( p < 0.001), ''rewetting agents'' ( p < 0.001) and ''time'' ( p < 0.001) on bond strength. Incorporation of 2% CHX to EWB preserved bond strength to SD and CAD and reduced interfacial nanoleakage after 12 months. Incorporation of 2% CHX to WWB also preserved bond strength to SD after ageing. Conclusions: Incorporation of chlorhexidine to ethanol-wet bonding has an interaction effect on preservation of bond durability to sound and caries-affected dentine. Clinical significance: Incorporation of chlorhexidine to ethanol-wet bonding with hydropho- bic adhesive enhances the success rate of aesthetic bonded restorations. [ABSTRACT FROM AUTHOR]

Summary: Objectives: This study examined the changes in hydraulic conductance and ultrastructure of dentine bonded with simplified etch-and-rinse adhesives to oxalate desensitiser pre-treated acid-etched dentine. Methods: Human dentine disks were acid-etched, treated with an oxalate desensitiser (BisBlock, Bisco), and bonded with One-Step (OS), Single Bond (SB), OptiBond Solo Plus (OB) or Prime and Bond NT (PB). Similar disks from each group were acid-etched, and bonded without oxalate pre-treatment. Hydraulic conductance of the specimens was measured at 20cm of water pressure and analysed with nonparametric statistical methods. Epoxy resin replicas of the smear layer-covered dentine and bonded dentine were examined with SEM for the extent of fluid transudation. Specimens bonded under perfusion were examined with TEM after tracer immersion. Results: OB and PB exhibited a highly significant reversal of the reduced hydraulic conductance obtained with BisBlock on unbonded acid-etched dentine. Profuse water transudation across the bonded dentine was observed from the replicas. Adhesive interfaces were covered with spherical globules that interfered with dentine hybridization. Conversely, no significant difference in hydraulic conductance was observed in SB, between Bisblock pre-treated, unbonded and bonded acid-etched dentine. Significantly lower hydraulic conductance was shown on application of OS to Bisblock-treated acid-etched dentine. Water transudation was sparse, interfering surface globular structures were absent, and only angular subsurface crystals were seen in the dentinal tubules. Conclusions: Convective water fluxes through dentine may be reduced by applying Bisblock to acid-etched dentine before bonding with One-Step or Single Bond. However, reducing adhesive permeability with the use of oxalate desensitiser is not applicable to low acidity adhesives such as OptiBond Solo Plus and Prime and Bond NT. [Copyright &y& Elsevier]

Abstract: This study examined the extent of organic solvent and water retention in comonomer blends with different hydrophilicity (Hoy''s solubility parameter for hydrogen bonding, ) after solvent evaporation, and the extent of tracer penetration in polymerised films prepared from these resins. For each comonomer blend, adhesive/solvent mixtures were prepared by addition of (1) 50wt% acetone, (2) 50wt% ethanol, (3) 30wt% acetone and 20wt% water and (4) 30wt% ethanol and 20wt% water. The mixtures were placed in glass wells and evaporated for 30–60s for acetone-based resins, and 60–120s for ethanol-based resins. The weight of the comonomer mixtures was measured before and after solvent evaporation. Resin films were prepared for transmission electron microscopy (TEM) after immersion in ammonical silver nitrate. The percentages of solvent and water retained in the comonomer mixtures, and between the acetone and ethanol groups were measured gravimetrically and were statistically compared. In comonomer-organic solvent mixtures, the percentage of solvent retained in acetone and ethanol-based mixtures increased significantly with hydrophilicity of the comonomer blends (). In resin-organic solvent–water mixtures, significantly more solvent and water were retained in the ethanol-based mixtures (), when compared to acetone-based mixtures after 60s of air-drying. TEM revealed residual water being trapped as droplets in resin films containing acetone and water. Water-filled channels were seen along the film periphery of all groups and throughout the entire resin films containing ethanol and water. The addition of water to comonomer-ethanol mixtures results in increased retention of both ethanol and water because both solvents can hydrogen bond to the monomers. [Copyright &y& Elsevier]