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OBJECTIVE: The purpose of this study was to evaluate the effectiveness of glazing, two zirconia, and two lithium disilicate polishing systems on surface roughness of a CAD/CAM lithium disilicate and virgilite ceramic with atomic force microscopy (AFM) and visual assessment performed by dental students and faculty. METHODS AND MATERIALS: Sixty maxillary right central incisor crowns made of a novel chairside CAD/CAM lithium disilicate and virgilite (CEREC Tessera) were milled for glazing and polishing. The crowns were divided into six groups: no polishing/glazing provided (NoP/G); glazed (GZ); glazed and polished with Brasseler Dialite LD Lithium Disilicate (DiLD); glazed and polished with Meisinger Luster Lithium Disilicate (LuLD); glazed and polished with Brasseler Dialite ZR Zirconia (DiZR); and glazed and polished with Meisinger Luster Zirconia (LuZR). Surfaces were scanned with AFM to measure roughness (Ra) and root mean square roughness (Rq) and generate micrographs. Crowns were visually assessed by 10 dental students and 10 dental school faculty members to determine clinical acceptableness. RESULTS: Glazing and all polishing kits significantly reduced Ra and Rq compared to no polishing/glazing. No significant Ra differences were found between glazing and all polishing kits (p>0.05). DiZR significantly reduced Rq compared to other groups (p<0.05). Visual assessment showed that GZ, LuLD, and DiZR were the most clinically acceptable crowns. CONCLUSION: Polishing and glazing considerably improve the surface smoothness of maxillary central incisor crowns fabricated out of a chairside CAD/CAM lithium disilicate and virgilite ceramic. Altogether, zirconia polishing systems provided smoother and more clinically acceptable surfaces than the lithium disilicate kits.
Subject(s)
Dental Polishing , Dental Porcelain , Humans , Materials Testing , Dental Polishing/methods , Surface Properties , Ceramics , Crowns , Computer-Aided Design , Microscopy, Electron, ScanningABSTRACT
We report on the commissioning of a full aperture backscatter diagnostics station for the kilojoule, nanosecond high repetition rate L4n laser operating at a wavelength of 527 nm at the Extreme Light Infrastructure (ELI) - Beamlines, Dolni Brezany, Czech Republic. Light scattered back from laser-plasma interaction into the cone of the final focusing lens is captured and split into different channels to measure the signatures of laser plasma instabilities from stimulated Brillouin scattering, stimulated Raman scattering, and two plasmon decay with respect to back scattered energy, its spectrum, and its temporal profile. The performance was confirmed in a commissioning experiment with more than 800 shots at laser intensities ranging from 0.5 × 1013 to 1.1 × 1015 W cm-2. These diagnostics are permanently installed at ELI Beamlines, and can be used to understand the details of laser-plasma interactions in experiments with kJ and 527 nm light. The large number of shots that can be collected in an experimental campaign will allow us to study the details of the laser-plasma interaction with a high level of confidence.
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OBJECTIVE: This case report describes a minimally invasive approach with tooth whitening and partial ceramic veneers in the esthetic zone with a 5-year follow-up. CLINICAL CONSIDERATIONS: The patient was initially concerned about the tooth color and previous direct resin composite restorations that chipped on the incisal edges of both maxillary central incisors. Tooth whitening and partial veneers for both central incisors were recommended after clinical evaluation. Two sessions of in-office tooth whitening, first with 35% hydrogen peroxide and later with 10% carbamide peroxide from first premolar to first premolar, were provided. Minimal tooth preparation that only removed the fractured composite restorations was performed followed by placement of feldspathic porcelain ultrathin partial ceramic veneers for both central incisors. We emphasize the benefits of minimal tooth preparation paired with partial ceramic veneers and the importance of masking discolored tooth structure with such thin veneers, including potential tooth whitening. CONCLUSIONS: Overall, we demonstrate a well-planned and executed restorative procedure combining tooth whitening and ultrathin partial ceramic veneers to achieve desired results in the esthetic zone that remained successful for five years.
Subject(s)
Dental Porcelain , Tooth Bleaching , Humans , Dental Porcelain/therapeutic use , Dental Porcelain/chemistry , Esthetics, Dental , Ceramics/therapeutic use , Composite Resins/chemistry , Dental VeneersABSTRACT
INTRODUCTION: After recent presentation of the first complete robot-assisted retroperitoneal nephroureterectomy with bladder cuff (RRNU) for patients with upper tract urothelial cancer (UTUC), we aimed to compare this new surgical technique with robot-assisted transperitoneal nephroureterectomy (TRNU) representing the current standard of care. METHODS: Robot-assisted nephroureterectomies (NUs) were retrospectively analyzed and compared based on two groups: transperitoneal versus retroperitoneal approach. Baseline data were collected for patient demographics, tumor characteristics, intra- (EAUiaiC) and postoperative (Clavien-Dindo) complications, and perioperative variables. Tumor characteristics included grade of malignancy, clinical stage, and surgical margin status. Short-term follow-up data including 30-day readmission rates were collected. Statistical analyses were performed assuming a significant p-value of < 0.05. RESULTS: The analysis includes perioperative patient data after proven UTUC of 24 TRNU versus 12 RRNU (mean age: 70 versus 71 years; BMI: 25.9 versus 26.1 kg/m2; CCI score ≥ 4: 83% versus 75%; ASA score ≥ 3: 37% vs 33%). Intraoperative (16.4% vs 0%, p = 0.35) and postoperative (25% vs 12.5%, p = 0.64) complications demonstrated no significant discrepancy. Notably, RRNU demonstrated significantly shorter surgery time (p < 0.05) and length of stay (p < 0.05). There was no significant difference in histopathological tumor characteristics, whereas significantly more lymph nodes were removed through RRNU (11.0±3.3 vs. 6.4±5.1, p < 0.05). Finally, no statistical difference was shown in short-term follow-up. CONCLUSION: We report the first head-to-head comparison between RRNU and TRNU. RRNU proves to be a safe and feasible approach which appears to be non-inferior to TRNU. RRNU expands the spectrum of minimally invasive treatment options, particularly for patients with major previous abdominal surgery.
Subject(s)
Carcinoma, Transitional Cell , Laparoscopy , Robotic Surgical Procedures , Robotics , Urinary Bladder Neoplasms , Humans , Aged , Nephroureterectomy , Urinary Bladder/pathology , Retrospective Studies , Carcinoma, Transitional Cell/surgery , Carcinoma, Transitional Cell/pathology , Urinary Bladder Neoplasms/surgery , Laparoscopy/methods , Robotic Surgical Procedures/methods , Treatment OutcomeABSTRACT
OBJECTIVE: This case report describes the use of a combination of a polychromatic resin composite restoration and resin infiltration to achieve a satisfactory esthetic outcome that has lasted over five years. CLINICAL CONSIDERATIONS: The patient's primary complaint was a desire to replace an existing stained resin composite on the facial and mesial surfaces of the maxillary left central incisor, and a white spot on the facial surface of the maxillary right central incisor. After clinical evaluation, the patient was offered either replacement of the restoration with a polychromatic restoration simulating a white spot, or a combined treatment with polychromatic composite and resin infiltration restorations, which was recommended. The patient selected the latter treatment. A putty matrix was fabricated, and a quick mock-up was done using various enamel and dentin shades of resin composite to determine proper material selection. The previous resin composite restoration was removed, and layers of new dentin, body, and enamel composite were placed. An interproximal matrix was used in order to provide ideal contour and contact. Finishing and polishing procedures were performed. The maxillary right central incisor was treated with resin infiltration in order to subdue the white spot on the facial surface. CONCLUSIONS: Polychromatic resin composite and resin infiltration restorations to replace a stained restoration and mask a white spot can achieve desired results in the esthetic zone and maintain them for five years.
Subject(s)
Dental Restoration, Permanent , Esthetics, Dental , Humans , Dental Restoration, Permanent/methods , Composite Resins/therapeutic use , Dental Enamel , Dental CareABSTRACT
BACKGROUND: While no gold standard exists for the management of Achilles tendon ruptures, surgical repair is common in healthy and active patients. Minimally invasive repair methods have become increasingly popular, while biomechanical equivalency hasn't been proven yet. METHODS: A mid-substance Achilles tendon rupture was created 6 cm proximal to the calcaneal insertion in 27 fresh-frozen cadaveric ankles. Specimens were randomly allocated to 1 of 3 repair techniques: Huttunen et al. (2014) (1) PARS Achilles Jig System, Nyyssönen et al. (2008) (2) Achilles Midsubstance SpeedBridge™, Schipper and Cohen (2017) (3) Dresdner Instrument and subsequently subjected to cyclic loading with 250 cycles each at 1 Hz with 4 different loading ranges (20-100 N, 20-200 N, 20-300 N, and 20-400 N). FINDINGS: After 250 cycles no significant differences in elongation were observed between PARS and Dresdner Instrument(p = 1.0). Furthermore, SpeedBridge™ repairs elongated less than either Dresdner Instrument (p = 0.0006) or PARS (p = 0.102). Main elongation (85%) occurred within the first 10 cycles with a comparable elongation in between 10 and 100 and 100-250 cycles. While all repairs withstood the first 250 cycles of cyclic loading from 20 to 100 N, only the PARS (468 ± 175) and Midsubstance SpeedBridge™ (538 ± 208) survived more cycles. Within all 3 groups suture cut out was seen to be the most common failure mechanism. INTERPRETATION: Within all groups early repair elongation was seen. While this was least obvious within the SpeedBridge™ technique, ultimate strengths of repairs (cycles to failure) were comparable across PARS and SpeedBridge™ with a decline in the Dresdner Instrument group.
Subject(s)
Achilles Tendon , Tendon Injuries , Achilles Tendon/surgery , Biomechanical Phenomena , Cadaver , Humans , Rupture/surgery , Suture Techniques , Sutures , Tendon Injuries/surgeryABSTRACT
OBJECTIVES: The case report describes a minimally invasive, multidisciplinary approach to a single discolored anterior tooth, with internal bleaching using traditional Japanese paper (Washi), a gingivoplasty with a three-dimensional (3D) printed surgical guide, and ultrathin feldspathic porcelain veneers. CLINICAL CONSIDERATION: The patient's primary concern was improving her smile. After clinical evaluation, internal tooth bleaching for the discolored tooth and gingivoplasty with restoration of the maxillary anterior six teeth and first premolars was recommended. The internal tooth whitening was accomplished with sodium perborate mixed with 30% hydrogen peroxide impregnated in Washi and sealed in the root canal with glass ionomer. Once the tooth bleaching was completed, the 3D printed surgical guide was placed in the patient's maxillary anterior region and used to guide soft tissue recontouring. After 6 months, ultrathin feldspathic porcelain veneers were placed. CONCLUSION: Well-planned restorative procedures combining internal tooth bleaching using Washi, gingivoplasty performed with electrosurgery using a 3D printed surgical guide, and ultrathin feldspathic porcelain veneers can achieve the desired results in the esthetic zone and remain successful for 4 years.
Subject(s)
Tooth Bleaching , Tooth Discoloration , Dental Porcelain , Dental Veneers , Esthetics, Dental , Female , Humans , Hydrogen Peroxide/therapeutic use , Tooth Bleaching/methodsABSTRACT
OBJECTIVE: The purpose of this study was to evaluate the effectiveness of five different polishing systems on a computer-aided design and computer-aided manufacturing (CAD/CAM) polymer-infiltrated ceramic-network restoration with nanoscale assessment using atomic force microscopy (AFM) and visual assessment performed by dental school senior students and faculty members. METHOD: Forty-eight full coverage crowns were milled out of polymer-infiltrated ceramic-network CAD/CAM blocks (Vita Enamic) for polishing with one company proprietary, two ceramic and two composite polishing systems. The prepared crowns were divided into six groups: (1) no polishing (control); (2) polishing with Vita Enamic Polishing Kit (VEna); (3) polishing with Shofu Porcelain Laminate Polishing Kit (SCer); (4) polishing with Brasseler Dialite Feather lite All-Ceramic Adjusting & Polishing System (BCer); (5) polishing with Shofu Composite Polishing Kit (SCom); and (6) polishing with Brasseler Composite Polishing Kit (BCom). The polished crown surface topography was observed, and surface roughness and area were measured with AFM. In addition, polished crowns were visually assessed by 15 senior dental students and 15 dental school faculty members. RESULTS: All polishing treatments significantly reduced the surface roughness and area of the crown compared with the control. SCom and BCom showed significantly higher surface area than VEna, and the SCer and BCer groups were intermediate, showing no significant difference from either VEna or SCom and BCom. There were no significant differences in surface roughness between any of the systems. Dental students and faculty members classified the groups polished with VEna, SCer, and BCer groups as clinically acceptable, and they selected BCer group as the best polished restorations and the control group as the least polished restorations. CONCLUSIONS: Ceramic and composite polishing systems produced similar polishing results as that observed using a company proprietary polishing system. However, effectiveness for polishing using a company proprietary and ceramic polishing system tends to be higher than composite polishing systems.
Subject(s)
Ceramics , Polymers , Computer-Aided Design , Dental Polishing , Dental Porcelain , Humans , Materials Testing , Surface PropertiesABSTRACT
INTRODUCTION: In this pilot study, we wished to determine if C-reactive protein (CRP) levels could be a useful severity or treatment biomarker for canine atopic dermatitis (AD). Nine atopic dogs received allergen immunotherapy for 1 year. Blood was collected before and at four re-evaluation visits. At each time point, the skin lesions were graded with the Canine Atopic Dermatitis Extent and Severity Index (CADESI) 4, and the plasma CRP levels were measured by Enzyme-linked Immunosorbent Assay (ELISA). We found a significant yet minimal correlation between the CRP levels and the CADESI4 scores. The CRP levels were not significantly different between dogs with AD of increasing severity. Finally, there was no correlation between the percentage change in CADESI4 and CRP values during immunotherapy. In conclusion, the lack of significant difference in CRP levels between dogs of increasing AD severity and lack of correlation between percentage changes in skin lesion and CRP values suggest that this protein would not be a clinically-useful biomarker in atopic dogs.
INTRODUCTION: Dans cette étude pilote, nous avons souhaité déterminer si les niveaux de protéine C-réactive (CRP) pourraient être un biomarqueur de gravité ou de traitement utile pour la dermatite atopique canine (DA). Neuf chiens atopiques ont reçu une immunothérapie allergénique spécifique pendant un an. Du sang a été prélevé avant et lors de quatre visites de réévaluation. À chacune de ces visites, les lésions cutanées ont été classées au moyen de l'indice d'étendue et de gravité de la dermatite atopique canine (CADESI) 4 et les taux plasmatiques de CRP ont été mesurés par dosage immuno-enzymatique (ELISA). Nous avons trouvé une corrélation significative mais minime entre les niveaux de CRP et les scores CADESI4. Les niveaux de CRP n'étaient pas significativement différents entre les chiens atteints de DA de gravité croissante. Enfin, il n'y avait pas de corrélation entre le pourcentage de changement des valeurs de CADESI4 et de CRP pendant l'immunothérapie. En conclusion, l'absence de différence significative des taux de CRP entre les chiens de gravité croissante de DA et le manque de corrélation entre les changements de pourcentage de lésion cutanée et les valeurs de CRP suggèrent que cette protéine ne serait pas un biomarqueur cliniquement utile chez les chiens atopiques.
Subject(s)
Biomarkers/blood , C-Reactive Protein/analysis , Dermatitis, Atopic/veterinary , Desensitization, Immunologic/veterinary , Dog Diseases/therapy , Animals , Dermatitis, Atopic/blood , Dermatitis, Atopic/pathology , Dermatitis, Atopic/therapy , Dog Diseases/blood , Dog Diseases/diagnosis , Dogs , Pilot Projects , Plasma/chemistryABSTRACT
BACKGROUND: In surgical fields there has been a perceivable paradigm shift during the last decade concerning patient pre- and rehabilitation. Current literature suggests close interdisciplinary collaboration after complex procedures such as radical cystectomy in order to optimize perioperative patient care for the benefit of "fast-track" surgery. OBJECTIVES: To compose a catalogue of standardized measures after radical cystectomy based on guidelines set by the ERAS®-Society. RESULTS: The protocol commences with preoperative education in order to improve the physical and psychological condition of the patient. Crucial aspects in peri- and postoperative patient care are gentle surgical technique, adequate pain management, early mobilization and oral food intake, early removal of drains and foreign material and a seamless return to normal, daily life. CONCLUSIONS: Prospective data analysis will be the next step in order to establish the effectiveness of the protocol especially regarding postoperative complications and median duration of hospital stay.
Subject(s)
Cystectomy , Urinary Bladder Neoplasms , Academic Medical Centers , Enhanced Recovery After Surgery , Humans , Length of Stay , Postoperative Complications/prevention & control , Prospective Studies , Urinary Bladder Neoplasms/surgeryABSTRACT
The importance of measurement quality cannot be over emphasized in medical applications, as one is dealing with life issues and the wellbeing of society, from oncology to new-borns, and more recently to patients of the COVID-19 pandemic. In all these dire situations, the accuracy of fluid delivered according to a prescribed dose can be critical. Microflow applications are growing in importance for a wide variety of scientific fields, namely drug development and administration, Organ-on-a-Chip, or bioanalysis, but accurate and reliable measurements are a tough challenge in micro-to-femto flow operating ranges, from 2.78 × 10-4 mL/s down to 2.78 × 10-7 mL/s (1000 µL/h down to 1 µL/h). Several sources of error have been established such as the mass measurement, the fluid evaporation dependent on the gravimetric methodology implemented, the tube adsorption and the repeatability, believed to be closely related to the operating mode of the stepper motor and drive screw pitch of a syringe pump. In addition, the difficulty in dealing with microflow applications extends to the evaluation of measurement uncertainty which will qualify the quality of measurement. This is due to the conditions entailed when measuring very small values, close to zero, of a quantity such as the flow rate which is inherently positive. Alternative methods able to handle these features were developed and implemented, and their suitability will be discussed.
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Even though sexual activity frequently takes place with another person, research rarely focuses on how partners influence each other's sexual lives. This study used the sexual dyad to compare the concept of actual versus perceived discrepancy in sexual interest and explored how each is related to older partnered individuals' sexual satisfaction. Further, the study assessed the robustness of the association between sexual interest discrepancy and sexual satisfaction, if any, by controlling for emotional intimacy. The actor-partner interdependence model (APIM) using structural equation modeling (SEM) was applied to examine 677 heterosexual couples ages 60 to 75 in Norway, Denmark, Belgium, and Portugal. Although a couple's actual discrepancy in sexual interest was not predictive of female and male partners' sexual satisfaction, perceived discrepancy was negatively associated with sexual satisfaction in both partners after controlling for emotional intimacy. This indicates that the subjective feelings of being sexually dissimilar seem to be more important to sexual satisfaction than the actual mismatch among partners in older heterosexual couples. Moreover, the finding that emotional intimacy is linked with sexual satisfaction underscores the importance of a broader perspective on sexuality among older adults.
Subject(s)
Heterosexuality , Orgasm , Aged , Female , Humans , Male , Middle Aged , Personal Satisfaction , Sexual Behavior , Sexual PartnersABSTRACT
Hodgkin lymphoma (HL) in older patients appears to be a different disease compared with younger patients with historically lower survival rates. This is related to a variety of factors, including increased treatment-related toxicity, the presence of comorbidities, and biologic differences. In order to better assess the clinical characteristics, treatment strategies, and outcome of this particular population, we conducted a population-based, retrospective analysis including 269 patients with HL older than 60 years (median age 71 years, range 60-94), treated between 2000 and 2017 in 15 referral centers across Switzerland. Primary endpoints were overall survival (OS), progression-free survival (PFS), and cause-specific survival (CSS). The vast majority of patients were treated with curative intent, either with a combined modality approach (chemotherapy followed by radiation therapy) or with systemic therapy. At a median follow-up of 6.6 years (95% confidence interval [CI], 6.0-7.6), 5-year PFS was 52.2% (95% CI, 46.0-59.2), 5-year OS was 62.5% (95% CI, 56.4-69.2), and 5-year CSS was 85.1.8% (95% CI, 80.3-90.1) for the entire cohort. A significant difference in terms of CSS was observed for patients older than 71 years in comparison to patients aged 60-70 years (hazard ratio 2.6, 1.3-5.0, p = 0.005). Bleomycin-induced lung toxicity (BLT) was documented in 26 patients (17.7%) out of the 147 patients exposed to this compound and was more frequent in patients older than 71 years (15/60, 25%). Outcome of HL pts older than 71 years appeared to decrease substantially in comparison to the younger counterpart. Treatment-related toxicities appeared to be relevant, in particular, BLT. New, potentially less toxic strategies need to be investigated in prospective clinical trials in this particular frail population.
Subject(s)
Hodgkin Disease/epidemiology , Age Factors , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Retrospective Studies , SwitzerlandABSTRACT
The ways in which the discrepancy between one's own interest in sex and that of one's partner may affect personal sexual satisfaction has rarely been systematically studied, especially among older adults. Previous research among younger adults indicates that a discrepancy in sexual desire can be detrimental in terms of several relationship outcomes, including sexual satisfaction. This study aimed to investigate a conceptual model of sexual satisfaction among coupled older adults which posits that the association between perceived discrepancy in sexual interest and sexual satisfaction is mediated by the frequency of sexual activity and emotional closeness during sex. Data from a probability-based postal survey that included 2695 partnered heterosexual adults aged 60-75 years from four European countries (Norway, Denmark, Belgium, and Portugal) were used to test the mediation model. Due to expected gender differences in the two mediators, all analyses were carried out separately for men and women. The findings supported the proposed model, suggesting that as an individual's perception of a discrepancy in sexual interest increases, his or her levels of sexual frequency and perceived closeness during sex decrease-which in turn diminishes sexual satisfaction. The results of this study provide insights into links among sexual interest, sexual frequency, emotional closeness, and sexual satisfaction in older adults, and point to substantial similarities in the sexuality of aging men and women in this regard.
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CLINICAL RELEVANCE: Some bulk-fill flowable resin composites produce less cuspal deflection than a conventional incrementally filled flowable resin composites. SUMMARY: Objective: This study investigated simulated cuspal deflection and flexural properties of bulk-fill and conventional flowable resin composites.Methods and Materials: Five bulk-fill and six conventional flowable resin composites were evaluated. Aluminium blocks with a mesio-occlusal-distal cavity were prepared and randomly divided into groups for each of the different measurement techniques and were further subdivided according to the type of flowable resin composite. The simulated cuspal deflection caused by the polymerization of resin composite within an aluminium block was measured using a highly accurate submicron digimatic micrometer or a confocal laser scanning microscope (CLSM). In addition, the flexural properties of tested resin composites were measured to investigate the relation between cuspal deflection and flexural properties, and the resin composites were observed using scanning electron microscopy.Results: Simulated cuspal deflection of some bulk-fill flowable resin composites was found to be significantly lower than or similar to those for conventional counterparts, regardless of the measurement method. There were statistically significant differences in flexural properties depending on the material, regardless of the type of flowable resin composite. Pearson correlation analysis did not reveal a statistically significant relationship between flexural properties and cuspal deflection.Conclusion: These results indicate that some bulk-fill flowable resin composites exhibit lower cuspal deflection with the bulk-filling technique than is shown by conventional flowable resin composites using the incremental filling technique. Simulated cuspal deflection can be measured using either a micrometer or CLSM, but this experiment failed to show a significant relationship between cuspal deflection and flexural properties of flowable resin composites.
Subject(s)
Composite Resins , Flexural Strength , Materials Testing , PolymerizationABSTRACT
Canine atopic dermatitis (CAD) is a prevalent inflammatory skin disease of dogs worldwide. Certain breeds such as the West Highland White Terriers (WHWT) are predisposed to suffer from CAD. Microbial dysbiosis is known to play a significant role in the pathogenesis of the disease, which is similar to its human counterpart, atopic dermatitis (AD). To date, no large cohort-study has been conducted in a predisposed dog breed to study the impact of the early-life microbiota on the development of CAD, as well as the possible implication of factors such as hygiene and access to the outdoors. In this study skin samples of 143 WHWT, including 109 puppies up to three weeks old and 34 parent dogs, from 17 breeders, were subjected to 16S rRNA gene and ITS2 amplicon sequencing to disclose the bacterial and fungal oral and skin microbiota, respectively. The oral samples served as a control group to confirm differences between haired and mucosal surfaces. The cutaneous microbiota differed between sample sites and age of the dogs. The season of sampling, geographical origin as well as hygiene status of the household and the access to the outdoors shaped the skin microbiota of the puppies significantly. However, we found that the individual early-life microbiota did not predispose for the later development of CAD.
Subject(s)
Bacteria/classification , Dermatitis, Atopic/microbiology , Dermatitis, Atopic/veterinary , Fungi/classification , Mouth/microbiology , Skin/microbiology , Aging , Animals , Bacteria/genetics , Bacteria/isolation & purification , DNA, Intergenic/genetics , Dermatitis, Atopic/pathology , Dog Diseases/microbiology , Dog Diseases/pathology , Dogs , Female , Fungi/genetics , Fungi/isolation & purification , Male , Microbiota/physiology , Pruritus/microbiology , Pruritus/pathology , Pruritus/veterinary , RNA, Ribosomal, 16S/geneticsABSTRACT
OBJECTIVE: The purpose of this study was to evaluate whether different enamel etching methods with reduced etching times would improve the bonding effectiveness of universal adhesives. METHODS AND MATERIALS: Three enamel etching methods, phosphoric acid ester monomer (PPM) etching, phosphoric acid (PPA) etching, and polyalkenoic acid (PLA) etching, and three universal adhesives, G-Premio Bond (GP), Prime&Bond elect (PE), and Scotchbond Universal Adhesive (SU), were evaluated. Initial bond strengths and fatigue strengths of universal adhesives to ground enamel and ground enamel etched for less than one, five, 10, and 15 seconds using different etching methods were determined. The bonded fatigue specimens were loaded using a sine wave at a frequency of 20 Hz for 50,000 cycles or until failure occurred with a staircase method. Atomic force micrograph (AFM) observations along with measurements of surface Ra roughness and modified surface area of enamel with different etching protocols were also conducted. RESULTS: The bond fatigue durability of universal adhesives to enamel with PPA etching from less than one to 15 seconds and PLA etching for 15 seconds was significantly higher than that to ground enamel. The bond fatigue durability to enamel with PPM etching was not increased compared with ground enamel. The surface Ra roughness and surface area obtained with AFM of enamel increased after PPA and PLA etching, and those values were significantly higher than those of ground enamel. Furthermore, surface Ra roughness and surface area with PPA etching were significantly higher than those with PLA etching. However, surface Ra roughness and surface area of enamel with PPM etching were similar to those of ground enamel regardless of etching time. CONCLUSION: PPA etching for less than one to 15 seconds and PLA etching for 15 seconds improve universal adhesive bonding, surface Ra roughness, and surface area of enamel. However, PPM etching is not effective, regardless of etching time, in improving bonds strengths, increasing surface roughness, and increasing surface area.
Subject(s)
Acid Etching, Dental , Dental Bonding , Dental Cements , Dental Enamel , Materials Testing , Phosphoric Acids , Resin Cements , Shear Strength , Surface PropertiesABSTRACT
The evolution of bonded restorations has undergone great progress over several decades. Nonetheless, life spans of bonded restorations are limited mainly because of the eventual incidence of recurrent caries. Over time, water and waterborne agents (acids, enzymes) degrade the components of the dentin/restoration interface, allowing bacterial colonization and dentin reinfection at the margins of the restoration. We developed a 2-tier protective technology consisting of priming/coating dentin with amphipathic and antimicrobial peptides (AAMPs) to obtain hydrophobic/water-repellent and antibiofilm dentin-resisting recurrent caries around bonded restorations. We tested a series of AAMPs to assess their structure-function relationships as well as the effects of different dentin-conditioning methods on the structural features of AAMP-coated dentin. We found relation between the secondary structure of AAMPs (high portion of ß-sheet), the antimicrobial potency of AAMPs, and the AAMPs' ability to form hydrophobic coatings on dentin. We also determined that AAMPs had preferential adsorption on the mineral phase of dentin, which suggested that peptides arrange their cationic and hydrophilic motifs in direct contact with the negatively charged minerals in the hydrophilic dentin. These results led us to explore different dentin-conditioning methods that would increase the mineral/collagen ratio and their effect on AAMP immobilization. We innovatively imaged the spatial distribution of the AAMPs in relation to the dentinal tubules and collagen network using a minimally invasive multimodal imaging technique: multiphoton-second harmonic generation. Using multiphoton-second harmonic generation imaging, we determined that partial deproteinization of dentin increased the amount of immobilized AAMPs as compared with the total etched dentin at the dentin surface and extended deeply around dentinal tubules. Last, we analyzed the release rate of AAMPs from dentin coatings in artificial saliva to predict their stability in the clinical setting. In conclusion, priming dentin with AAMPs is a versatile new approach with potential to fortify the otherwise vulnerable adhesive-based interfaces.