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.

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.

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.

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.

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.

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.

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.

Exogenous non-crosslinked collagen enhances granulation tissue formation in dermal excision wounds in guinea pigs.

Based on previous observations indicating a role for collagen peptides in eliciting a positive feedback for collagen biosynthesis, this study was initiated to elucidate the effect of non-crosslinked collagen on granulation tissue formation in dermal excision wounds. The wounds were treated with either non-crosslinked or crosslinked native collagen, or left untreated as controls. Granulation tissue was analyzed for collagen type I mRNA, for levels of interstitial collagen and for the number of blood vessels. The results indicated significant increases in procollagen type I mRNA, in interstitial collagen, in the number of blood vessels and in epithelial advance in the non-crosslinked collagen-treated wounds relative to the untreated controls. It is assumed that the presence of non-crosslinked collagen in a healing wound enhances both procollagen type I biosynthesis and the repair process of dermal wounds, due to the more readily released collagen peptides derived from this exogenous collagen dressing.

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.

Topological differences in the expression of collagen type I and collagen type III mRNAs in the rat gingiva.

Collagen mRNA levels in the gingival cells of molars and incisors in rats were measured and correlated with the ratio of interstitial collagen to DNA in these regions. Hybridization of 32P-labeled specific cDNA probes for collagen types I and III with total RNA isolated from gingival tissue of rat molars and incisors showed that the steady-state levels of mRNAs of type I was significantly higher in the molars than in the incisors (molars/incisors = 2.12 +/- 0.12, P < 0.004). However, the ratio of interstitial collagen to DNA in the gingiva of the molars was significantly lower than that found in the incisors (collagen/DNA = 4.13 +/- 0.90 and 12.89 +/- 1.24 respectively, P < 0.001). It is suggested that the difference between the mRNA levels and those of interstitial collagen may reflect an intrinsic characteristic presumably associated with the different modes of mastication between molars and incisors of the rat.

Lack of influence of cyclosporin A on levels of gingival procollagen types I and III mRNAs in rats of different ages.

Previous studies showed that gingival overgrowth following cyclosporin A (CsA) administration is not associated with an increase in interstitial collagen. It also was shown that CsA causes a significant decrease in collagen content within the gingival stroma. In order to determine whether this decrease is caused by down-regulation of collagen mRNA, the procollagen mRNA level in gingiva of young and old rats was measured correlated with the ratio of interstitial collagen to DNA in these regions. Hybridization of 32P-labelled cDNA probes for procollagen types I and III with total RNA extracted from the molar gingiva showed that administration of Csa did not change the steady-state levels of mRNAs for both procollagens in the gingiva of either young or old rats. The ratio of gingival interstitial collagen to DNA was significantly reduced in the CsA-treated animals (4.2 +/- 0.85) relative to the controls (7.8 +/- 1.6). It is concluded that the reduction in interstitial collagen following CsA treatment is not age-related, and is most probably caused by increased degradation rather by decreased biosynthesis.

The effect of centrifugal force on the transcription levels of collagen type I and collagenase in cultured canine gingival fibroblasts.

An orthodontically treated tooth is often destabilized in its newly corrected location and relapses towards its original position. Hitherto, the explanation for this phenomenon was that orthodontic force brings about "stretching" of gingival collagen fiber, which "pull back" the tooth towards its pretreatment position. A previous ultrastructural study showed that after force application the gingival collagen fibres were torn, laterally spaced and of increased diameter. Therefore, they could not "pull back" the tooth and be the cause of the relapse. In the present study, in order to find a more plausible explanation at the molecular level, the effect of pressure on the gene transcription of collagen type I and tissue collagenase was examined by semiquantitative, reverse transcriptase-polymerase chain reaction assay. Attached buccal gingiva was excised from anaesthetized dogs and gingival fibroblasts were grown in culture. Following application of pressure (0.167 kg/l g cell mass), the transcription of collagen type I was increased while that of tissue collagenase was decreased. These results corroborate the ultrastructural in vivo findings that orthodontic force is associated with larger amounts of collagen type I in the gingiva.

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.

Orthodontic-prosthetic treatment to replace maxillary incisors exfoliated because of improper use of orthodontic elastics: a case report.

This article describes the iatrogenic exfoliation of maxillary central incisors following the improper use of orthodontic elastic bands. The unsecured rubber band had migrated apically and caused an almost "bloodless extraction" of both maxillary central incisors. A combined orthodontic-prosthetic solution was used to replace the lost incisors.

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.

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.

The effect of different porcelain conditioning techniques on shear bond strength of stainless steel brackets.

With the increasing demand for adult orthodontics, a growing need arises to bond attachments to porcelain surfaces. Optimal adhesion to a porcelain surface should allow orthodontic treatment without bond failure but not jeopardize porcelain integrity after debonding. In this study, 90 glazed porcelain facets were divided into three groups according to different conditioning techniques: (1) roughening with a coarse diamond; (2) hydrofluoric acid 8%; (3) microetching with 60 micron aluminum oxide particles. Each group was divided into three groups and stainless steel brackets were then bonded to the conditioned porcelain with three different dental adhesives. The adhesives used were: (1) silane+Right-On; (2) silane+Concise; (3) High-Q-Bond without silane. Four additional facets (three of which conditioned as above and one intact) were analyzed macroscopically and by scanning electron microscopy. Shear bond strength was measured with an Instron universal testing machine and a macroscopic examination of the debonded porcelain surfaces was performed. Results showed that shear bond strength was highly influenced by both conditioning technique and the adhesive. Shear bond strength of the High-Q-Bond groups was significantly lower than both the silane+Right-On and the silane+Concise groups; nevertheless the shear bond strength achieved by High-Q-Bond was enough to sustain full orthodontic treatment duration (except for the group conditioned by roughening with a coarse diamond). Scanning electronic microscopy analysis revealed that diamond roughening and microetching produced only a surface-peeling pattern, whereas hydrofluoric acid conditioning produced an extensive in-depth penetrating pattern. Hydrofluoric acid preparation produced greater shear bond strength than both diamond roughening and microetching. After debonding by means of a shearing force, the percentage of damaged porcelain surfaces in the silane+Concise groups was significantly higher than the silane+Right-On and High-Q-Bond groups.

Gingival response to a new multipurpose dental adhesive: a histologic study in dogs.

The biocompatibility of cementing materials is a prerequisite for any dental procedure. In this study, the tolerance of gingival tissue to an advanced fourth-generation dental adhesive (High-Q-Bond) was tested in dogs. The results from High-Q-Bond adhesive were compared with those obtained from Superbond C&B adhesive. Buccal class V subgingival cavities were restored with either High-Q-Bond or Superbond C&B adhesive Untreated teeth served as normal intact controls. The teeth with the attached buccal gingivae were extracted and processed for histologic examination. The histologic observations showed an inflammatory response in the gingiva of the Superbond C&B adhesive-treated teeth, whereas the High-Q-Bond fillings exhibited no noticeable adverse effect on the gingival tissue.

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.