The efficacy and safety of different doses of calcitriol combined with neutral phosphate in X-linked hypophosphatemia: a prospective study.

The present study was the first prospective cohort evaluated the efficacy and safety of different doses of calcitriol in XLH children. The results suggested that a dose of 40 ng/kg/day calcitriol, compared with 20 ng/kg/day, was more effective in relieving the rickets, with similar safety outcomes. Further investigations were expected to set more dose groups. INTRODUCTION: Dose recommended for calcitriol in X-linked hypophosphatemia (XLH) varies in different studies. Therefore, we aimed to compare the efficacy as well as the safety of 20 ng/kg/d and 40 ng/kg/d calcitriol in Chinese XLH pediatrics population. METHODS: A 2-year, randomized, open-label, prospective study recruited 68 XLH children, which were randomized to receive either 40 ng/kg/day or 20 ng/kg/day calcitriol. Efficacy endpoints were the total Thacher ricket severity score (RSS) change from baseline to month 12 and 24, the difference in serum TALP level, fasting serum phosphate level, body height Z-score, and frequency of dental abscess. Safety assessments were done using renal ultrasound nephrocalcinosis grades (0-4), fasting serum and 24 h urine calcium level, and the occurrence of hyperparathyroidism. RESULTS: The decrease in the total RSS from baseline was more significant in the high-dose group at 12 (difference 0.87, p = 0.049) and 24 month (difference 1.23, p = 0.011). The serum TALP level was significantly lower in the high-dose group at 6 months. Pi level, height Z-score change, frequency of dental abscess and ratio of de novo nephrocalcinosis were comparable. A lower incidence of secondary hyperparathyroidism was seen in the high-dose group (p < 0.0001). CONCLUSION: For the first time in this prospective cohort, 40 ng/kg/d calcitriol was shown to be the more effective therapy in XLH children than the 20 ng/kg/d. Moreover, 40 ng/kg/d calcitriol was not associated with increasing adverse events. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT 03,820,518.

[Application of folded flap in laryngeal and hypopharyngeal function reconstructions after surgery of piriform sinus cancer].

Objective: To investigate the use of folded flap for repair of laryngeal and hypopharyngeal defect and the clinical efficacies of laryngeal and hypopharyngeal function reconstructions after surgery of piriform sinus cancer. Methods: A retrospective analysis was performed for 10 cases of piriform sinus cancer that were treated in the Second Norman Bethune Hospital of Jilin University from January 2020 to April 2023 and all patients were males, aged 42-68 years. The first choice of treatment for all patients was surgery. After function neck dissection and tracheotomy, partial laryngectomy and hypopharyngectomy were carried out. The folded island flaps were prepared and used for the repairs of laryngeal and hypopharyngeal defects and the reconstructions laryngeal and hypopharyngeal functions. The patients were followed up. Results: The laryngeal and pharyngeal cavities were reconstructed well in 10 patients, and all the flaps survived, with no case of pharyngeal fistula. All patients were able to eat normally through the mouth at 2 weeks after surgery without obvious choking, and 4 patients completed the swallowing function evaluation without aspiration or only a small amount of aspiration. All the 10 patients underwent postoperative radiotherapy. The postoperative follow-up time was 5.4-41.4 months, and there was no case with tumor recurrence or death. Laryngoscopy showed that 8 patients had a spacious new laryngeal orifice, which met the conditions for extubation, of whom 7 patients had their tracheal tubes removed and 1 patient was still under observation, and that 2 patients had a slightly narrowed new laryngeal orifice due to a thick skin flap, with further follow-up observation. All patients retained their phonatory functions after surgery. Conclusion: Folded island flap can be used for the function reconstructions of the larynx and hypopharynx after surgery of pyriform sinus cancer.

[A two-dimensional photographic and three-dimensional digital dental model comparative analysis in maxillary anterior teeth].

Objective: To assess the accuracy of two-dimensional (2D) photographs in measuring esthetic parameters of the maxillary anterior teeth by comparing them with measurements obtained from three-dimensional (3D) dental models. Methods: A total of one hundred volunteers (49 males, 51 females, aged 18-23 years) were recruited from School and Hospital of Stomatology, Wuhan University from January to February 2024. 3D digital models of their dentitions were obtained using an intraoral scanner, and standardized frontal 2D intraoral photographs were captured with a digital camera. The lengths, widths and width/length ratio of the bilateral incisors, lateral incisors and canines were measured on both the 3D digital models and the 2D intraoral photographs. The width ratios of adjacent maxillary anterior were also calculated on the 2D intraoral photographs and the frontal view of 3D digital models. Results: The widths of lateral incisors [(5.85±0.60) mm] and canines [(4.73±0.71) mm] and the lengths of canines [(8.72±0.96) mm] in the 2D intraoral photographs were significantly lower than those in 3D digital models [(6.65±0.59), (7.76±0.60), (8.90±0.86) mm] (t=-18.24, P<0.001; t=-54.43, P<0.001; t=-4.40, P<0.001), while there were no significant differences in the lengths and widths of the other teeth (P>0.05). The width/length ratios measured from the 2D intraoral photographs for the lateral incisors and canines (0.74±0.08, 0.55±0.08) were significantly lower than those measured in the 3D digital models (0.84±0.09, 0.88±0.09) (t=-19.68, P<0.001; t=-50.21, P<0.001), and the width/length ratio of the central incisors showed no significant difference between the two groups (P>0.05). The width ratios of canines/lateral incisors and lateral incisors/central incisors measured on the 2D intraoral photographs (0.72±0.06, 0.85±0.11) were significantly smaller than those measured in the frontal view of 3D digital models (0.75±0.06, 0.89±0.11) (t=-9.31, P<0.001; t=-6.58, P<0.001). Conclusions: There is a difference between 2D and 3D measurement results of teeth in the esthetic area and the magnitude of the difference varies with their position in the dental arch. When analyzing the measurement of the anterior teeth, it is necessary to choose the appropriate method according to the target tooth position.

Effects of Different Primers on the Bond Strength to Properly and Excessively Etched Ceramic-coated Zirconia.

PURPOSE: To determine the effects of various primers on the immediate and long-term bond strength of ceramic-coated ultratranslucent zirconia that is properly or excessively etched. METHODS AND MATERIALS: Ceramic-coated zirconia plates were etched with 9.5% hydrofluoric acid (HF) for 2 or 5 minutes, after which the surface morphology and elemental composition were examined. The etched specimens were treated with different primers including methacryloyloxydecyl dihydrogen phosphate (MDP)-only containing primer, silane-only containing primer, MDP and silane-containing ceramic primer as well as MDP and silane-containing adhesive system. For surface contact angle and shear bond strength (SBS) data, the difference between groups was evaluated by one-way analysis of variance (ANOVA) and three-way ANOVA factorial analysis, respectively. The statistical significance level of 0.05 was set and the Tukey test and the Dunnett-T3 test were used for post-hoc multiple comparisons. RESULTS: Excessive etching (9.5% HF for 5 minutes) led to overconsumption of the glass layer and exposure of zirconia substrate compared to proper etching (9.5% HF for 2 minutes). Among different primers, the surface contact angle of the silane-only containing primer group was the lowest. The silane-only containing primer and MDP and silane-containing ceramic primer produced higher shear bond strength of properly and excessively etched ceramic-coated zirconia, respectively, both before and after thermal aging. CONCLUSIONS: The silane-only containing primer and MDP and silane-containing primer can obtain better immediate and long-term shear bond strength for properly and excessively etched ceramic-coated zirconia, respectively.

[Characteristics of consonant among children with speech sound disorder].

Objective: To investigate the characteristics of consonant among children with speech sound disorder (SSD) and to provide an empirical basis for the subsequent clinical evaluation and evidence-based intervention. Methods: In this retrospective research a total of 1 395 children diagnosed with SSD from the Language-Speech Clinic of the Department of Children Health Care, Children's Hospital, Capital Institute of Pediatrics from January 2007 to December 2018 were enrolled and underwent the phonological examination on the lexical level with picture naming, according to phoneme development in Chinese mandarin. The Chi-square trend test was applied to analyze the differences and trends of the proportion of consonant error subtypes in children of different age groups. The Chi-square test was conducted to compare the proportion of consonant error subtypes in different gender. Results: The 1 395 children diagnosed with SSD included 1 044 boys and 351 girls, with an age of (5.1±0.8) years. The occurrence of consonant errors in different locations of articulation was the highest for blade-alveolar /l/ (71.8%, 1 002/1 395) and the lowest for labial/b/(9.3%, 130/1 395). The occurrence of consonant errors of labial/p/f/, supra-dental/z/c/s/, blade-alveolar/t/l/, blade-palatal/ch/r/, velar/k/h/, and lingua-palatal/q/decreased with age (all P<0.05). The occurrence of consonant errors of labial/b/m/, supra-dental/z/c/, blade-alveolar/n/l/, blade-palatal/sh/, velar/h/, and lingua-palatal/x/were higher in boys than those in girls (10.3% (108/1 044) vs. 6.3% (22/351), 11.4% (119/1 044) vs. 6.0% (21/351), 64.8% (676/1 044) vs. 51.9% (182/351), 67.8% (708/1 044) vs. 59.8% (210/351), 16.7% (174/1 044) vs. 8.8% (31/351), 73.7% (769/1 044) vs. 66.1% (232/351), 58.0% (606/1 044) vs. 47.6% (167/351), 24.0% (251/1 044) vs. 14.2% (50/351), and 39.9% (417/1 044) vs. 27.6% (97/351); χ²=5.167, 8.533, 16.889, 7.447, 12.863, 7.412, 11.650, 14.900, and 17.099, all P<0.05). The error types of consonant were substitution, omission, and distortion. Omission was the main error type of blade-alveolar/l/(53.3%, 743/1 395), distortion was the main error type of velar/h/(11.8%, 165/1 395), and substitution was the main error type of all other consonants. Substitution with blade-palatal/ch/having the highest occurrence of error (60.2%, 840/1 395). Conclusions: The occurrence of the blade-alveolar/l/error is the highest in children with SSD, with boys demonstrating more serious articulation problems. The main error type of consonant is substitution, with blade-palatal/ch/having the highest occurrence of error. These results suggest the necessity of attending to preschoolers' articulation development. Phonological training targeting blade-alveolar/l/and blade-palatal/ch/should be carried out as early as possible.

[Analysis of functional speech sound disorder and related erroneous consonants in children].

Objective: To investigate the features and trends of functional speech sound disorder and related erroneous consonants in children, so as to provide evidence for clinical evaluation and rational intervention. Methods: Clinical data of 1 562 children diagnosed with functional speech sound disorder in the language-speech clinic of the Department of Child Health Care, Children's Hospital, Capital Institute of Pediatrics from January 2007 to December 2018 were analyzed retrospectively. By using the mandarin phonetic test table, the picture-naming method was adopted to test the word-level pronunciation. The Chi-square test was conducted to analyze the incidence of consonant errors in different age groups, gender and different places of articulation. The trend in incidence of the consonant errors in different age groups and during the last 12 years were analyzed by chi-square trend test. Results: A total of 1 562 cases were diagnosed with functional speech sound disorder, including 1 171 males and 391 females, the age was 4-17 years. The incidence of consonant errors in different places of articulation was 43.0% (672/1 562) for labial, 47.0% (734/1 562) for lingua-palatal, 63.7% (995/1 562) for velar, 77.7% (1 213/1 562) for linguo-alveolar, 78.9% (1 233/1 562) for apico-dental and 81.6% (1 274/1 562) for palatal. The incidence of consonant errors in males on labial, lingua-palatal, linguo-alveolar and palatal was higher than that in females (44.7% (523/1 171) vs. 38.1% (149/391), 49.1% (575/1 171) vs. 40.7% (159/391), 80.1% (938/1 171) vs. 70.3% (275/391), 82.8% (970/1 171) vs. 77.7% (304/391), χ²=5.138, 8.379, 16.126 and 5.042,all P<0.05). The incidence of consonant errors on labial, lingua-palatal, velar, linguo-alveolar, apico-dental and palatal decreased with age (χ²=27.023, 13.230, 20.579, 29.718, 26.390, and 17.887, all P<0.01). The incidence of consonant errors on labial, linguo-alveolar, apico-dental increased with years (χ²=9.030, 51.894 and 18.507, all P<0.01). Conclusions: The incidence of palatal errors is the highest in children with functional speech sound disorder. As part of the palatal errors could not be completely self-healing with growing, the phonological therapy for palatal errors should be carried out as early as possible. The incidence of consonant errors on labial, linguo-alveolar, and apico-dental presents an upward tendency with years, more attention should be paid to the factors related to the acquisition of these consonants.

Titanium-coated mesh versus standard polypropylene mesh in laparoscopic inguinal hernia repair: a prospective, randomized, controlled clinical trial.

OBJECTIVE: We aimed to compare the clinical outcome of titanium-coated mesh and polypropylene mesh in laparoscopic inguinal hernia repair. METHODS: A total of 102 patients who received laparoscopic inguinal hernia repair in January-June 2016 in Beijing Chao-Yang Hospital were enrolled in this study. Patients were randomly divided into two groups, receiving either titanium-coated mesh (n = 50) or standard polypropylene mesh (n = 52). Multiple clinical parameters were collected and analyzed, including clinical manifestations, operative time, intraoperative blood loss, hospital stay, hospital cost, recovery time, and postoperative complications. RESULTS: All procedures were completed. A statistical difference between two groups was not identified in regards to operative time, intraoperative blood loss, hospital stay, and recovery time (P > 0.05). Three cases with seroma and 15 with foreign body sensation were reported in the titanium-coated mesh group; 9 cases with seroma and 17 with foreign body sensation were reported in the standard polypropylene mesh group. There was no significant difference in the incidence of seroma and/or foreign body sensation. A lower hospital cost but longer recovery period was documented in the standard polypropylene mesh group (P < 0.05). No recurrence, infection or chronic pain was observed during 1-year follow-up in both groups. CONCLUSION: Titanium-coated mesh possesses comparable clinical qualities as the standard polypropylene mesh but with a shorter recovery period. Therefore, this mesh is promising for clinical practice though the cost is higher than the standard polypropylene mesh.

Biological properties of carbon nanotubes.

Carbon nanotubes are novel materials with unique physical and chemical properties, and have been considered for use in numerous technological applications. More recently, attention has turned to the unique biological and medical properties of these materials. In this review, the processing, chemical properties, physical properties, nucleic acid interaction, cell interaction, and toxicologic properties of nanotubes are described. Finally, future directions in this area are discussed.

Understanding ß-mannanase from Streptomyces sp. CS147 and its potential application in lignocellulose based biorefining.

Hydrolytic enzymes such as cellulase and hemicellulase have been attracted in lignocellulose based biorefinery. Especially, mannanase has been a growing interest in industrial applications due to its importance in the bioconversion. In this study, an extracellular endo-ß-1,4-D-mannanase was produced by Streptomyces sp. CS147 (Mn147) and purified 8.5-fold with a 43.4% yield using Sephadex G-50 column. The characterization of Mn147 was performed, and the results were as follows: molecular weight of ∼25 kDa with an optimum temperature of 50°C and pH of 11.0. The effect of metal ions and various reagents on Mn147 was strongly activated by Ca(+2) but inhibited by Mg(+2) , Fe(+2) , hydrogen peroxide, EDTA and EGTA. Km and Vmax values of Mn147 were 0.13 mg/mL and 294 µmol/min mg, respectively, when different concentrations (3.1 to 50 mg/mL) of locust bean gum galactomannan were used as substrate. In enzymatic hydrolysis of heterogeneous substrate (spent coffee grounds), Mn147 shows a similar conversion compared to commercial enzymes. In addition, lignocellulosic biomass can be hydrolyzed to oligosaccharides (reducing sugars), which can be further utilized for the production of biomaterials. These results showed that Mn147 is attractive in quest of potential bioindustrial applications.

Role of self-assembled gold nanodots in improving the electrical and optical characteristics of zinc oxide films.

We have studied the effect of embedding nanocrystalline Au particles on the electrical and optical characteristics of ZnO films. Au-embedded epitaxial ZnO films were deposited on (0001) sapphire substrates with a pulsed laser deposition technique. The crystalline quality of both the ZnO matrix and Au nanoparticles was investigated by X-ray diffraction and transmission electron microscopy. Composite films were characterized by photoluminescence, optical absorption, and low-temperature electrical resistivity measurements. Photoluminescence spectra of theses films showed a sharp excitonic peak at 3.22 +/- 0.05 eV without any signature of green band emission. Electrical resistivity measurements showed these films to be highly conducting, with a room-temperature resistivity of 3.4 +/- 0.2 m omega-cm.

[An approach to the morphology of buccal armature of Sergentomyia nankingensis].

OBJECTIVE: To describe the morphological variation of pointed teeth of buccal armature of Sergentomyia nankingensis in a supplementary study. METHODS: The morphology of Sergentomyia nankingensis was observed and the specimens included S. nankingensis captured from the field as well as the female ones bred in the laboratory and their offspring of first generation. RESULTS: The buccal armature of females and males, consists of about 10-19 and 8-15 pointed teeth and the pigmented plate is polymorphous. In the nature, the number of pointed teeth of buccal armature of Sergentomyia is unstable, varying in more than 10 teeth in the same species sometimes. CONCLUSION: Identification of species needs large amount of specimens for comparative observation. Sergentomyia sandfly should be raised separately and individually for morphological observation of its newly emerged offspring, especially when the sandfly specimens and data collected in the field were not sufficient.

Pulsed laser deposition of antimicrobial silver coating on Ormocer microneedles.

One promising option for transdermal delivery of protein- and nucleic acid-based pharmacologic agents involves the use of microneedles. However, microneedle-generated pores may allow microorganisms to penetrate the stratum corneum layer of the epidermis and cause local or systemic infection. In this study, microneedles with antimicrobial functionality were fabricated using two-photon polymerization-micromolding and pulsed laser deposition.The antibacterial activity of the silver-coated organically modified ceramic (Ormocer)microneedles was demonstrated using an agar diffusion assay. Human epidermal keratinocyte viability on the Ormocer surfaces coated with silver was similar to that on uncoated Ormocer surfaces. This study indicates that coating microneedles with silver thin films using pulsed laser deposition is a useful and novel approach for creating microneedles with antimicrobial functionality.

Nanoscale surface topography enhances cell adhesion and gene expression of madine darby canine kidney cells.

Substrate topography is one of the key factors that influence cell behavior, such as cell attachment, adhesion, proliferation and differentiation. In the present work, nanostructures were produced on polystyrene Petri dish by polarized laser irradiation with the wavelength of 266 nm and the energy of 3.0 mJ/cm2. Cell adhesion, growth and gene expression of Madine darby canine kidney (MDCK) cells cultured on smooth and nanogrooved substrates were investigated. The results indicated that cells preferred to adhere and grow on nanogrooved substrate. The distribution of cell cycle for cells on smooth substrates was different from that on nanogrooved substrate. The percentage of G1 phase cells on nanogrooved substrate (48.6 +/- 1.4%) was lower than that on smooth substrate (57.6 +/- 4.4%), while the percentage of cells on nanogrooved substrate in S (30.2 +/- 0.5%) and G2/M (21.2 +/- 1.1%) phase was higher than those on smooth substrate (25.1 +/- 1.5% and 17.3 +/- 3.3%, respectively). Moreover, the gene expression of cyclin D1 and keratin 18, which was examined by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR), was significantly enhanced by nanogrooves, with an increase of cyclin D1 mRNA by 98% and an increase of keratin 18 mRNA by 75%. In conclusion, the nanogrooved surface features on polystyrene could alter cell cycle and enhance gene expression of cyclin D1 and keratin 18 in MDCK cells, which partly explained the increased cell adhesion and growth on nanogrooved substrate.

The effect of paclitaxel-loaded nanoparticles with radiation on hypoxic MCF-7 cells.

BACKGROUND AND OBJECTIVE: The inability of radiotherapy to eradicate completely certain human tumours may be due to the presence of resistant hypoxic cells. Several studies have confirmed the radiosensitizing effect of paclitaxel, a microtubular inhibitor. The object of this study was to evaluate the physicochemical characteristics of paclitaxel-loaded nanoparticles, and determine the ability of the released paclitaxel to radiosensitize hypoxic human breast carcinoma cells (MCF-7) with respect to radiation dose. METHODS: The poly(d,l-lactide-co-glycolide) (PLGA) nanoparticles containing paclitaxel were prepared by o/w emulsification-solvent evaporation method. The morphology of the paclitaxel-loaded nanoparticles was investigated by scanning electron microscopy. The drug encapsulation efficiency (EE) and in vitro release profile were measured by high-performance liquid chromatography. Cell cycle was evaluated by flow cytometry. Cell viability was measured by the ability of single cells to form colonies in vitro. RESULTS: The prepared nanoparticles were spherical with diameter between 200 and 800 nm. The EE was 85.5%. The drug release pattern was biphasic with a fast release rate followed by a slow one. Co-culture of human breast carcinoma cells (MCF-7) with paclitaxel-loaded nanoparticles demonstrated that released paclitaxel retained its bioactivity to block cells in the G2/M phase of the cell cycle and effectively sensitized hypoxic MCF-7 cells to radiation with radiosensitivity shown to be dependent of radiation dose at levels of dosages studied. The sensitizer enhancement ratio for paclitaxe-loaded nanoparticles at 10% survival is approximately 1.4. CONCLUSION: This work has demonstrated that paclitaxel can be effectively released from a biodegradable PLGA nanoparticle delivery system while maintaining potent combined cytotoxic and radiosensitizing abilities for hypoxic tumour cells.

The effect of saliva or serum on bacterial and Candida albicans colonization on type I collagen.

Colonization of Candida albicans on oral surfaces can serve as a reservoir for disseminated infections, such as aspiration pneumonia and gastrointestinal infection, particularly in the immunocompromised host. Therefore, the aim of this study was to investigate the effects of salivary and serum pellicles on C. albicans, Streptococcus mutans, S. sanguis, Lactobacillus and Actinomyces colonization on type I collagen, a major organic component of periodontal ligaments. The colonization potential of two isolates each of C. albicans, S. mutans and S. sanguis, and a single isolate each of Lactobacillus and Actinomyces to uncoated (control), saliva-coated or serum-coated type I collagen plates (surface area 143 mm(2), Cell Disk; Sumitomo, Tokyo, Japan) was examined using a bioluminescent adenosine triphosphate assay based on firefly luciferase-luciferin system. The results revealed that with mutans streptococci, a saliva pellicle was significantly more effective in promoting bacterial colonization compared with the pellicle-free collagen disc, and the serum-coated sample significantly inhibited the colonization of streptococci (anova; P < 0b01). In contrast, in the case of C. albicans, Lactobacillus and Actinomyces isolates, a serum pellicle was significantly more effective in promoting the colonization, followed by saliva pellicle and uncoated specimen (anova; P < 0b01). These results suggested that crevicular fluid rich in seruminous components would promote the colonization of Candida, Lactobacillus and Actinomyces on type I collagen as opposed to streptococci which showed greater avidity to saliva-coated collagen.

A field emission SEM and HVTEM study of collagen fiber bundles in the lamina propria of the palatine mucosa in the developing mouse.

The ultrastructural development of the surface belonging to the epithelium-connective tissue interface of the hard and soft palatine mucosa of mouse was studied using field emission scanning electron microscopy and high voltage transmission electron microscopy methods. The tissues were analysed at 18 days of gestation, and, 1, 3, 7, 14, 21, 30 and 90 days after birth. The three-dimensional architecture of the connective tissue in the lamina propria showed different shapes. The papillae began to form on days 7 and 14 but continued to growth until the adult period. Different stages of primary and secondary connective tissue papillae were recognized in the hard palatine mucosa whereas the soft palate showed erect connective tissue papillae, small round formations containing taste buds and several openings of the salivary glands ducts.

Interactions between thermal cycled resilient denture lining materials, salivary and serum pellicles and Candida albicans in vitro. Part I. Effects on fungal growth.

In the present study, the growth of a single isolate of Candida albicans on seven saliva-, serum-coated or protein free (uncoated), thermocycled (4-70 degrees C for 1 min, respectively; 0, 1000 and 10 000 times) commercial resilient lining materials was investigated by monitoring pH changes in growth media. The inhibitory effect of the tissue conditioners on fungal growth was observed using three parameters, i.e. (i) the delay in the onset of the rapid decline in pH, (ii) the reduction in the rate of pH change and (iii) the pH minima reached. In the case of control soft liners (not thermocycled and uncoated), the antifungal effect appeared to depend upon the type of commercial soft liner used. Thus, an initial delay in pH decline and a very high pH minima were observed with fluoric and heat-cured silicone materials. High pH minima were also observed with cold-cured acrylic soft liners, whereas cold-cured silicone materials did not significantly differ from heat-cured acrylic resin (P>0.05). However, the antifungal effect of the materials was significantly reduced both by thermal cycling (ANOVA, P<0.01) and a layer of protein coating (saliva, P<0.05; serum, P<0.01). These results, taken together, suggest that the ageing of the materials and the biological fluids of the host, particularly serum, promote yeast growth on soft lining materials.

Changes in surface roughness and colour stability of soft denture lining materials caused by denture cleansers.

Soft denture lining materials were immersed into solutions of denture cleansers for 8 h at room temperature, and immersed into distilled water for the remainder of the 24-h period at 37 degrees C. Surface roughness of the soft denture lining materials was measured by contact type surface roughness instrument. For the colour stability test, soft denture lining materials were immersed in the denture cleansers as described above for 180 days. Finally, the colour changes of each material were quantitatively measured by a photometrical instrument to obtain the colour differences between newly processed specimen and immersed specimens (P < 0.01). An autopolymerizing silicone material, Evatouch, exhibited severe changes in surface roughness by all denture cleanser, and the generic material GC Denture Relining showed the minimal changes. Severe colour changes were also observed with some liner and cleanser combinations (P < 0.01). Except for Evatouth, the four silicone soft liners were more stable in surface roughness and in colour change than the two acrylic soft liners. One autopolymerizing silicone (GC denture relining) and one heat curing silicone (Molloplast B) demonstrated the best stability.

Biofilm formation of Candida albicans on the surfaces of deteriorated soft denture lining materials caused by denture cleansers in vitro.

Candidal colonization and subsequent biofilm formation on denture materials are important in the development of pathogenesis, such as denture stomatitis. Routine use of denture cleansers is one of the most effective methods of denture plaque control, although the incompatibility of soft liners and denture cleansers cause damage to the materials. The present study, biofilm formation of Candida albicans on the surfaces of soft denture lining materials, immersed in denture cleansers for 180 days were studied. Seven commercially available soft denture lining materials, were artificially deteriorated by immersion into three commercially available denture cleansers for 180 days, and subsequent fungal growth and biofilm formation were studied by measuring pH of the media and by the use of adenosine triphosphate (ATP) analysis. Fungal biofilm formation on the deteriorated soft liners varied depending upon the combination of the soft liners and denture cleansers. Several combinations of soft liners with denture cleansers exhibited the significantly high colonization capacity as compared with each sample immersed in distilled water, used as individual controls. The relationship between the biofilm formation on the samples of each material and the surface roughness of the soft lining materials was analyzed. However, no significant correlation was observed. The results, taken together, suggested that fungal colonization could be predominantly regulated by the combination of lining material with denture cleansers. In clinical terms, our findings suggests that daily cleansing of soft lining materials with mismatched denture cleansers promoted the subsequent biofilm formation of fungi on the materials.