Sialochemistry and cortisol levels in patients with Sjogren's syndrome.

OBJECTIVES: (i) To determine whether salivary cortisol and electrolyte levels differ between patients with Sjogren's syndrome (SjS) and healthy individuals. (ii) To assess correlations between whole-saliva cortisol and some clinical manifestations in patients with SjS. METHODS: A total of 24 healthy women (mean age 49.3±9.8) served as controls (C) vis-à-vis 17 patients with SjS (mean age 55.5±15.7). Salivary cortisol concentration was determined, and sialochemistry analysis was performed. RESULTS: Significantly lower saliva flow rates and higher salivary chloride (Cl(-) ), potassium (K(+) ), and Ca(2+) levels were found in the SjS group. No significant differences or correlations were found in other parameters, including sodium (Na(+) ), magnesium (Mg(2+) ), phosphate ((-) ), urea (U), and salivary cortisol levels. CONCLUSION: Increased whole-salivary output of Cl(-) and K(+) in SjS may reflect release from apoptotic rests of acinar cells after secondary necrosis. Normal levels of salivary Na(+) , Mg(2+) , and (-) argue against concentration effect, deranged tubular function or cortisol (mineralocorticosteroid) effect as the cause for these findings. Increased salivary Ca(2+) levels probably reflect leakage of plasma Ca(2+) through the injured oral mucosa in SjS. In spite of disease-associated stress, salivary cortisol, a stress biomarker, was not increased, suggesting insufficient hypothalamus-pituitary-adrenal (HPA) axis response and/or local consumption of cortisol by lymphocyte infiltrates.

2-Butoxyethanol model of haemolysis and disseminated thrombosis in female rats: a preliminary study of the vascular mechanism of osteoarthritis in the temporomandibular joint.

Female rats develop haemolytic anaemia and disseminated thrombosis and infarction in multiple organs, including bone, when exposed to 2-butoxyethanol (BE). There is growing evidence that vascular occlusion of the subchondral bone may play a part in some cases of osteoarthritis. The subchondral bone is the main weight bearer as well as the source of the blood supply to the mandibular articular cartilage. Vascular occlusion is thought to be linked to sclerosis of the subchondral bone associated with disintegration of the articular cartilage. The aim of this study was to find out whether this model of haemolysis and disseminated thrombosis supports the vascular hypothesis of osteoarthritis. Six female rats were given BE orally for 4 consecutive days and the two control rats were given tap water alone. The rats were killed 26 days after the final dose. The mandibular condyles showed histological and radiological features consistent with osteoarthritis in three of the four experimental rats and in neither of the control rats. These results may support the need to explore the vascular mechanism of osteoarthritis further.

Increased dental trauma in children with attention deficit hyperactivity disorder treated with methylphenidate--a pilot study.

The purpose of this pilot study was to investigate the prevalence of trauma to incisor teeth in children with normal overjet and lip competence, treated with methylphenidate (Ritalin) for attention deficit hyperactivity disorder (ADHD). The study group consisted of 24 children (19 boys, 5 girls) aged 5-12 years (mean 8.45 +/- 2.25), diagnosed with ADHD and treated with methylphenidate at a minimal dosage of 10 mg per day. The control group consisted of 22 healthy children (13 boys, 9 girls) aged 5-12 years (mean 9.15 +/- 2.28). The dental examination included incisor relation measurements in the anterior segment (overjet), which was recorded using an orthodontic ruler. Lip competence was clinically determined, and anterior teeth were examined for dental trauma. The prevalence of dental trauma was significantly higher in the study group than in the control group (29.1% vs. 4.5% P = 0.02, t-test one tail). In conclusion, children with ADHD treated with methylphenidate have a high-risk for dental trauma. We believe that preventing dental trauma in this high risk group is possible. Consequently, the pediatrician and all medical staff attending to these children should encourage parents to consult frequently with a pediatric dentist to diagnose dental trauma and provide early treatment when needed.

Comparative proteomic analysis of human oral fluids according to gender and age.

BACKGROUND: Recently, interest in finding disease bio-markers in human body fluids including oral fluids (OF), mainly saliva has increased. However, the physiologic differences in salivary proteins according to gender and age should be explored to establish a clinical diagnostic tool. OBJECTIVE: To compare OF protein expression according to gender and age, using proteomic approaches. MATERIALS AND METHODS: Oral fluids from 27 healthy volunteers (14 males, 13 females) was collected and divided into three age-groups. OF proteins were separated by means of 2D-SDS-PAGE. A total of 51 proteins in 37 protein spots were identified by ESI-MS/MS. RESULTS: Gender differences revealed six proteins with significant higher expression in females, including ß-2-microglobulin and transferrin. Age differences revealed decrease in expression of eight proteins with aging among males and seven proteins differentially expressed with aging among females including prolactin inducible protein, Ig-k light chain, transferrin, and calgranulin-B. CONCLUSION: Proteomic analysis of OF revealed differences in protein expression according to gender and age and therefore can highlight future use of this technique for diagnostic purposes in health and in disease.

Cortisol daily rhythm in saliva of healthy school children.

AIM: To investigate the daily rhythm of cortisol levels in saliva of school children. SUBJECTS AND METHODS: Probands (10-14 years, both genders) were recruited via personal contact and school visits. Exclusion criteria included hormonal and dental treatments during the trial, pharmaceuticals containing cortisol, or poor oral hygiene. Each volunteer collected 20 saliva samples during one day at defined times starting immediately after waking up and ending at night. Additionally, they completed a sampling diary. Saliva samples were analysed in duplicate using a commercial cortisol luminescence kit. RESULTS: Cortisol concentration in saliva followed a daily rhythm. Within 20 minutes after waking up cortisol reached the highest level of 9.69 (+/-3.89) nmol/L. After 90 minutes cortisol concentration decreased linearly by 50% and stagnated at 4.14 (+/-1.93) nmol/L for 3 to 8 hours. Thereafter, levels decreased gradually reaching almost zero after 14 hours. Overall, no gender-specific differences in saliva cortisol levels were observed except for 3 time points: 3, 10 and 11 hours after waking. CONCLUSION: This study establishes guidelines for a normal secretion pattern, plus explores pain level measurements and their correlation to saliva cortisol levels in this age group.

Different proteomic protein patterns in saliva of Sjögren's syndrome patients.

OBJECTIVE: To investigate the salivary protein profile in patients with Sjögren's syndrome (SS), and healthy control subjects. MATERIALS AND METHODS: Unstimulated whole saliva samples were collected from 16 age-matched females; eight healthy subjects and eight patients diagnosed with SS (six primary SS, one incomplete SS and one primary SS associated with B cell lymphoma). Proteins were extracted and separated individually by 2D sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Selected protein spots of interest were analysed by electrospray ionization--tandem mass spectrometry. Obtained data were searched against the Swiss-Prot and NCBI non-redundant protein databases using Mascot software. RESULTS: Two groups of patterns of protein expression were observed in the eight SS patients: a major group (six patients) with significant expression differences from the healthy subjects and the second group (two patients) with a pattern similar to the eight healthy subjects. CONCLUSION: In this preliminary study, protein expression differences were found between SS patients and healthy subjects. Individual analysis of SS patients exhibited two patterns of protein expression with no direct relation to the clinical, serological or histological severity of disease. This study emphasizes the difficulty of the present proteomic knowledge to diagnose and monitor the sequel of SS development.

Improved orthodontic stainless steel wires coated with inorganic fullerene-like nanoparticles of WS(2) impregnated in electroless nickel-phosphorous film.

OBJECTIVE: To reduce friction between orthodontic stainless wires and bracket by coating the wire with nickel-phosphorous electroless film impregnated with inorganic fullerene-like nanoparticles of tungsten disulfide (IF-WS(2)) which are potent dry lubricants. METHODS: Coating was preformed by inserting stainless steel (SS) wires into electroless solutions of nickel-phosphorus (Ni-P) and IF-WS(2). The coated wires were analyzed by SEM (scanning electron microscope) and EDS (energy-dispersive X-ray spectrometer) as well as by tribological tests using a ball-on-flat device. Friction tests simulating archwire functioning of the coated and uncoated wires were carried out by an Instron machine. The adhesion properties of the coated wires after friction were analyzed by a Raman microscope. RESULTS: SEM/EDS analysis of the coated wires showed clear impregnation of the IF-WS(2) nanoparticles in the Ni-P matrix. The friction coefficient measured by the ball-on-flat tribometer was significantly reduced (from 0.25 to 0.08). The friction forces as measured with the Instron on the coated wire were reduced by up to 54% (4.00 N+/-0.19 uncoated vs. 1.85 N+/-0.21 coated). Raman spectra showed that even after extensive friction tests the Ni-P with the IF-WS(2) nanoparticles is attached to the underlying stainless steel wire. CONCLUSIONS: It is proposed that the wires coated with these nanoparticles might offer a novel opportunity to substantially reduce friction during tooth movement. A few tests undertaken to evaluate the toxicity of the fullerene-like nanoparticles have provided indications that they might be biocompatible.

A new system for scanning, measuring and analyzing dental casts based on a 3D holographic sensor.

OBJECTIVES: To evaluate the reliability of a new technique for measuring 3D-scanned orthodontic cast models with cross-section planes using teledent, a new software, developed at Technion - for the purpose of this research. EXPERIMENTAL VARIABLE: Thirty orthodontic plaster models were divided into three equal groups according to severity of teeth crowding. Measurements of mesio-distal tooth width and the arch length were performed manually on the casts using a conventional caliper. Thereafter, the models were scanned and processed into the software using a 3-D measuring scanner with a holographic sensor 'ConoProbe' (by Optimet, Jerusalem, Israel). teledent used two types of digital measurements; linear and cross-section planes to perform a space analysis on the scanned teeth. Significance was determined by the paired Wilcoxon rank sum test. RESULTS: Results show that 3D measurements of tooth width and arch length obtained by cross-section planes were generally similar to manual caliper measurements, while linear measurements were statistically smaller. When comparing space analysis, both digital measurements were statistically smaller than the caliper (p < 0.05). The difference in space analysis between the caliper and the cross-section plane measurements was very small (0.38-0.74 mm) and can be considered clinically acceptable. However, a difference of 1.19-3 mm between the linear measurements and the caliper might have clinical implications especially in severely crowded dentition. CONCLUSIONS: This study suggests that measurements performed by cross-section planes are as accurate as the manual caliper and can be employed clinically while the accuracy of linear measurements is sometimes questionable.

Proteomic analysis of protein components in periodontal ligament fibroblasts.

BACKGROUND: Characterization of periodontal ligament (PDL) fibroblast proteome is an important tool for understanding PDL physiology and regulation and for identifying disease-related protein markers. PDL fibroblast protein expression has been studied using immunological methods, although limited to previously identified proteins for which specific antibodies are available. METHODS: We applied proteomic analysis coupled with mass spectrometry and database knowledge to human PDL fibroblasts. RESULTS: We detected 900 spots and identified 117 protein spots originating in 74 different genes. In addition to scaffold cytoskeletal proteins, e.g., actin, tubulin, and vimentin, we identified proteins implicated with cellular motility and membrane trafficking, chaparonine, stress and folding proteins, metabolic enzymes, proteins associated with detoxification and membrane activity, biodegradative metabolism, translation and transduction, extracellular proteins, and cell cycle regulation proteins. CONCLUSIONS: Most of these identified proteins are closely related to the extensive PDL fibroblasts' functions and homeostasis. Our PDL fibroblast proteome map can serve as a reference map for future clinical studies as well as basic research.

Histopathologic changes in dental and oral soft tissues in 2-butoxyethanol-induced hemolysis and thrombosis in rats*.

BACKGROUND: 2-Butoxyethanol (2-BE; ethylene glycol monobutyl ether) is extensively used as a solvent in surface coatings, such as lacquers, enamels, and varnishes in industrial and household cleaning products. Its major toxicity is manifested in the circulation, as it induces hemolytic anemia and thrombosis in various organs. While 2-BE has been implicated in the induction of anemia in different species, the rat has proven most sensitive, especially the female of this species. The purpose of this study was to document the effects of 2-BE on dentition, the periodontal ligament, the tongue, the salivary glands, and the oral mucosa in male and female Fischer 344 rats. METHODS: The experiment included 40 rats divided into five groups. Four groups were exposed to 2, 3, or 4 daily doses of 2-BE, and a fifth group served as control. The rats were killed on days 2, 3, 4, and 29. The teeth and soft oral tissues were prepared for histopathologic observation. RESULTS: The histopathologic analysis showed that the major effect of 2-BE was exerted on the odontoblasts of the incisors and on molars, with greater effect on the incisors. Foci of damaged muscle cells in the tongue were also observed. The blood vessels were dilated and congested, and a primary thrombosis was seen in the dental pulp. CONCLUSIONS: The results of this study revealed a resemblance between the dental injuries in this rat model and those seen in sickle cell anemia in humans. This 2-BE animal model holds potential to assist in the discovery of preventive measures and/or treatment for dental injuries that occur in human diseases with hemolytic anemia.

Pressure simulation of orthodontic force in osteoblasts: a pilot study.

OBJECTIVES: To elucidate the RUNX2 gene expression induction in human osteoblasts after mechanical loading. DESIGN: Using a stringent pulse-chase protocol human osteoblasts were exposed to centrifugal pressure force for 30 and 90 min. Untreated control cells were processed in parallel. Before, and at defined times after centrifugation, total RNA was isolated. RUNX2 gene expression was measured using real-time quantitative reverse transcriptase polymerase chain reaction. The stress/control ratio was used to illustrate possible stimulatory or diminishing effects of force application. RESULTS: Immediately after 30 min of force application the RUNX2 gene expression was induced by a factor of 1.7 +/- 0.14 as compared with the negative control. This induction decreased rapidly and reached its pre-load levels within 30 min. Longer force applications (up to 90 min) did not change the RUNX2 gene expression. CONCLUSION: In mature osteoblasts centrifugal pressure force stimulates RUNX2 gene expression within a narrow time frame: loading of mature cells results in a temporary increase of RUNX2 expression and a fast downregulation back to its pre-load expression level. With this pilot study the gene expression behavior after mechanical stimuli could be determined with a simple laboratory setup.

The effect of centrifugal force on mRNA levels of collagenase, collagen type-I, tissue inhibitors of metalloproteinases and beta-actin in cultured human periodontal ligament fibroblasts.

BACKGROUND: The aim of orthodontic treatment is to relocate teeth abnormally positioned in the jaws. This is achieved by application of continuous force on the tooth, which is immediately being sensed by the periodontal ligament (PDL), bone and the gingiva. Since the bony response is mediated by the PDL, tooth movement is primarily a PDL phenomenon. OBJECTIVES: Thus, the purpose of the present study was to evaluate the direct effect of force (excluding the in vivo tissue response) on the molecular level of matrix metalloproteinase-1 (MMP-1) and collagen type-I (Col-I) in human PDL fibroblasts. METHODS: PDL cell culture flasks were centrifuged for 10, 20, 30, 60, 90 and 120 min by horizontal microplate rotor. The effect of force on mRNA levels of beta-actin, MMP-1, Col-I, tissue inhibitors-1 and -2 (TIMPs) genes was analyzed by RT-PCR. RESULTS: The results showed that force had no effect on the mRNA levels of beta-actin during the first 90 min of application of force, indicating for the first time the use of beta-actin gene as an internal invariant control. It increased the mRNA levels of MMP-1 while almost no effect on Col-I and TIMPs was observed. CONCLUSIONS: The results indicate that PDL remodeling following application of orthodontic force could be partly attributed to the direct effect of the force on MMP-1 gene expression in fibroblasts.

Prediction of premolar tooth lengths based on their panoramic radiographic lengths.

OBJECTIVE: Establishing a linear regression model for the determination of first premolar lengths based on panoramic radiographs. MATERIALS AND METHODS: The real lengths of 112 first premolars extracted for orthodontic reasons were measured and compared with their panoramic lengths. The teeth were divided into four groups according to their intraoral quadrant locations (T14, T24, T34, T44) and regression analysis was conducted for each group. RESULTS: A linear regression model for the prediction of tooth length (mm) based on the panoramic length was established (P < 0.0001): For group T14 the predicted length = (panoramic length x 0.698) + 2.61. For group T24 the predicted length = (panoramic length x 0.5056) + 7.844. For group T34 the predicted length = (panoramic length x 0.5075) + 9.282. For group T44 the predicted length = (panoramic length x 0.436) + 11.298. CONCLUSION: Prediction of all first premolar lengths using their panoramic images is both feasible and reliable.

Osteonecrosis in a chemically induced rat model of human hemolytic disorders associated with thrombosis--a new model for avascular necrosis of bone.

Bone injury occurs in human hemolytic disorders associated with thrombosis, such as beta-thalassemia and sickle cell disease. Exposure of rats to 2-butoxyethanol (BE) has been associated with hemolytic anemia, disseminated thrombosis, and infarction in multiple organs including bone. This rat model apparently mimics acute hemolysis and thrombosis in humans. To elucidate the extent of bone injury, male and female Fischer F344 rats were given 4 daily doses of 250 mg BE/5 ml water/kg of body weight. Tail vertebrae were studied by histopathology and magnetic resonance imaging (MRI). Thrombosis and infarction were seen in both sexes, but females were more severely affected. Lesions were characterized by extensive medullary fat necrosis, granulomatous inflammation, fibroplasia, growth plate degeneration, and new woven bone formation adjacent to necrotic bone trabeculae. MRI mean and standard deviation tissue-density data for both sexes indicated a significant (P < or = 0.05) decrease following 4-days treatment and a significant increase (P < or = 0.05) following an additional 24 days without treatment. Thus, MRI was useful in revealing BE-induced bone injury, which was predominantly necrotic initially and subsequently regenerative with proliferation of connective tissue and bone following postischemia recovery.

Basic fibroblast growth factor suppresses tropoelastin gene expression in cultured human periodontal fibroblasts.

Growth factors are known to play a major role in the regeneration of the periodontium. Basic fibroblast growth factor (bFGF) is a polypeptide growth factor considered to have a role in chemotaxis and mitogenesis of periodontal ligament (PDL) cells. The aim of this study was to assess the effect of bFGF on the transcription level of tropoelastin. As known controls, we assessed the transcription levels of collagen type I, collagen type II and the housekeeping gene, actin. Initially, PDL cells were cultured without bFGF for 3, 7 and 14 days. At each time point. total RNA was extracted and the levels of transcription were assessed by semiquantitative reverse transcription polymerase chain reaction (RT-PCR) assay. The results showed that tropoelastin mRNA is transcribed in PDL cells and its levels increased from minimal amounts by day 3 to maximal amounts by day 14 of culture. We further examined the effect of the addition of 10 ng/ml bFGF to the culture media by day 14. The results showed that the addition of bFGF suppressed the transcription level of tropoelastin. At that time, as expected, a decrease in collagen type I transcription level was shown, while the transcription level of collagen type III was not affected. The findings that elastin is transcribed in vitro by PDL cells, but only negligibly in vivo, imply mechanisms that downregulate or even shut down the expression of the elastin gene in the functioning PDL. Basic FGF might be one of the cytokines involved in control of elastin expression in vivo.

The effect of mechanical force on mRNA levels of collagenase, collagen type I, and tissue inhibitors of metalloproteinases in gingivae of dogs.

Orthodontic force causes an injury to and subsequent degradation of the attachment apparatus, thus leading to the transposition of the tooth. The gingiva, however, is compressed and sometimes becomes hypertrophic with tooth movement and often shrinks after treatment. To study the effect of force on the gingiva, we applied orthodontic force in dogs and analyzed gingival tissues 1, 2, 3, 7, 14, and 28 days later as well as after removing the force. The effect of force on mRNA levels of collagen type I (col-I), matrix metalloproteinase-1 (MMP- 1), and tissue inhibitors 1 and 2 (TIMPs) genes was analyzed by RT-PCR, and MMP-1 activity was determined by zymography. The results showed that force significantly increased both the mRNA levels of MMP-1 and its interstitial activity. After the removal of force, MMP-1 gene expression was significantly decreased. The results could partly explain the clinically observed shrinkage and adaptation of the gingiva during tooth movement.

A new multipurpose dental adhesive for orthodontic use: an in vitro bond-strength study.

The purpose of this study was to evaluate the compatibility of a new dental adhesive, High-Q-Bond (HQB) adhesive, for the bonding of orthodontic brackets by determining its bond strength and the mode of bond failure after debonding. Eighty extracted human premolars were divided into 4 groups, 20 in each group. In groups 1 and 2, stainless steel brackets were bonded to etched enamel with HQB and Right-On adhesives respectively. In groups 3 and 4, the same adhesives were used to bond stainless-steel brackets to roughened, old amalgam restorations prepared in the teeth. After 72 hours of incubation in saline solution at 37 degrees C, debonding was performed with a shearing force. The force at bond failure was recorded, and the mode of bond failure was examined. Results showed that when bonding to enamel, both the HQB and the Right-On material achieved adequate bond strength, and no significant difference was found between the two. However, after debonding, the HQB material left no adhesive on the enamel, whereas the Right-On material left significant amounts of adhesive on the enamel. When bonding to amalgam, the HQB material had a significantly higher shear bond strength than did the Right-On adhesive. It is suggested that HQB can be applied for orthodontic use, but further clinical studies are required to evaluate its efficacy.

Immediate placement of implants in extraction sites of maxillary impacted canines.

BACKGROUND: Treatment of asymptomatic impacted maxillary canines in adults is inevitable when primary canine becomes lost through extraction or exfoliation or when the impacted tooth becomes symptomatic. Treatment alternatives include an orthodontic procedure to bring the unerupted tooth to the dental arch or prosthetic replacement of the missing tooth. The authors describe an alternative treatment that involves immediate placement of implants into extraction sockets of the teeth. CASE DESCRIPTION: A patient with bilateral palatally impacted upper canines chose to have the unerupted teeth removed and replaced with implants and crowns. Two hydroxyapatite cylindrical implants were inserted through the alveolar ridge into the extraction sites. The unfilled areas in the extraction sites, around the dental implants, were packed and covered with demineralized freeze-dried bone allograft in conjunction with a collagen membrane barrier. Six months after implantation, computed tomography revealed complete osseous fill of the extraction defects and no bone loss around the implants. The implants were uncovered, and porcelain-fused-to-metal restorations were fabricated and placed. CLINICAL IMPLICATIONS: This treatment modality avoids the need for conventional preparation of teeth as part of prosthetic reconstruction or prolonged orthodontic treatment aimed at bringing the impacted canine to the dental arch. Combining the implantation with bone augmentation preserved the alveolar bone and shortened the treatment period.

Severe high Angle Class II Division 1 malocclusion with vertical maxillary excess and gummy smile: a case report.

Severe Class II Division 1 malocclusion with vertical maxillary excess and gummy smiles can be treated in several ways. Early orthodontic treatment with vertical control may decrease the malocclusion as well as improve the appearance. In severe cases, orthognathic surgery might be the optimal solution. The following case report describes a patient with a severe gummy smile, where the final esthetic improvement was achieved by using a periodontal procedure after orthodontic treatment.

Gingival response to orthodontic force.

Orthodontic tooth movement is brought about by prolonged application of force on the attachment apparatus. This results in cellular and extracellular changes within the periodontium. As shown in numerous studies, tooth movement is achieved after the remodeling of alveolar bone and the response of the periodontal ligament to the mechanical force. Although gingival changes have also been found to be an important factor in the overall response, the effect of orthodontic tooth movement on the gingiva has been investigated to a lesser extent. Unlike bone and periodontal ligament, which regain their original structure after removal of force, the gingival tissue does not regain its pretreatment structure, a fact on which a hypothesis has been made that tooth relapse after removal of retention may be associated with changes in the gingiva. The present review summarizes available data on the effect of orthodontic force on collagen, elastin, and collagenase in the gingiva and its relevance to understanding the mechanism of tooth relapse.