Parathyroid-hormone-related protein induces expression of receptor activator of NF-{kappa}B ligand in human periodontal ligament cells via a cAMP/protein kinase A-independent pathway.

UNLABELLED: Periodontal ligament (PDL) cells play important roles in root resorption of human deciduous teeth by odontoclasts (osteoclast-like cells). However, it is unclear how PDL cells regulate osteoclastogenesis. We examined the effects of PTHrP, TGF-beta, and EGF, which are all secreted by the tooth germ, on tartrate-resistant acid-phosphatase-positive (TRAP+) cell formation using co-cultures of human PDL cells and mouse spleen cells. Only PTHrP promoted TRAP+ cell formation in co-cultures. PTHrP induced receptor activator of NF-kappaB ligand (RANKL) mRNA expression and slightly reduced osteoprotegerin (OPG) expression in PDL cells. The cAMP/PKA inhibitors Rp-cAMP, H89, and PKI did not affect PTHrP-induced TRAP+ cell formation. The PKC inhibitor, Ro-32-0432, suppressed RANKL expression in PDL cells and PTHrP-induced TRAP+ cell formation. However, this inhibitor directly modulated the number of osteoclast precursors. Thus, PTHrP induces osteoclastogenesis by increasing the relative expression level of RANKL vs. OPG in PDL cells via a cAMP/PKA-independent pathway. ABBREVIATIONS: PTHrP, parathyroid-hormone-related protein; TGF-beta, transforming growth factor-beta; EGF, epidermal growth factor; RANKL, receptor activator of NF-kappaB ligand; OPG, osteoprotegerin; PDL, periodontal ligament; TRAP, tartrate-resistant acid phosphatase; PKA, protein kinase A; PKC, protein kinase C; MAP, mitogen-activated protein; ERK, extracellular signal-regulated kinase; cAMP, cyclic Adenosine 3'5'-Monophosphate.

Fluid and protein secretion by the submandibular glands of weanling rats in response to various agonists.

Secretion of fluid and protein by the submandibular glands of 25-day-old rats was investigated by stimulation with 22 sialogogues classified into five categories, four cholinergic, five beta 1-, seven alpha 1- and three alpha 2-adrenergic, and three peptidergic, at optimal doses. For fluid secretion, cholinergic and peptidergic agonists were the most powerful, whereas the beta 1- and alpha 1-adrenoceptor agonists were the most effective for the concentration of protein among the five categories, except for methoxamine. For total output of protein, the beta 1- and alpha 1-adrenoceptor agonists and pilocarpine were the most powerful among the 22 agonists, except for methoxamine and norephedrine. Cholinergic, peptidergic and alpha 2-adrenergic agonists among the five categories were less effective for protein secretion, except for pilocarpine. For the specific activity of esteroprotease, methoxamine and oxymetazoline, as alpha-adrenoceptor agonists, were the most powerful among the 22 agonists. Thus fluid and protein secretion evoked from the submandibular glands of weanling rats in response to a wide variety of agonists are similar to those of adult rats.

Sialogogic activity in the rat of peptides analogous to [Tyr8]-substance P in which substitutions have been made in the N-terminal amino acids.

In order to elucidate the regulatory roles for salivation of amino acids in positions 1-4 of the N-terminal region of [Tyr8]-substance P (SP), the structure-sialogogic activity correlations of various synthetic octa- to undecapeptides replaced in positions 1-4 of [Tyr8]-SP with each of 19 common amino acids, one by one, and with the same sequence of the C-terminal hepatapeptide as that of [Tyr8]-SP, were studied in the submandibular glands of rats after intraperitoneal injection. Each of 19 octa-, nona-, deca- and undecapeptides with replaced amino acids and a penta- to decapeptide with the progressive elimination of the N-terminal portion were newly synthesized by the multipin peptide method. All octa- to undecapeptides replaced with each of 19 common amino acids in positions 1-4 had sialogogic activities. In 19 octa- and decapeptides in which P4 and P2 had been replaced, four and three replacements, respectively, had significantly increased secretory activities. In contrast, in 19 nonapeptides in which K3 had been replaced, none had significantly increased secretory activities. Furthermore, in 19 undecapeptides in which R1 had been replaced, most replacements had significantly increased or equipotent activities for fluid secretion. It is concluded that amino acids in the N-terminal region of various tachykinins may not need to be strictly conserved and that amino acid residues in the N-terminal portion, R1 in particular and P2, may strongly inhibit secretory activity.

Fluid and protein secretion by the submandibular glands of weanling rats in response to cholinergic and peptidergic agonists at various doses.

Fluid and protein secretion by the submandibular glands of 25-day-old rats were examined and compared in response to three cholinergic and four peptidergic sialogogues at various doses. All cholinergic and peptidergic agonists used were potent sialogogues for the submandibular glands of the weanling rats over the wide range of doses used. The cholinergic agonists, bethanechol and methacholine and the peptidergic agonists, substance P, substance PTyr8 and eledoisin-related peptide used intravenously, acted similarly to each other on the submandibular glands of the rats, late in the natural weaning period, but carbachol and physalaemin had slightly different effects. Of the peptidergic agonists, physalaemin was the most potent sialogogue among four tachykinins tested at the low dose. The types of protein secreted by the submandibular glands of the weanling rats in response to all sialogogues used here were typical of the beta-type. These results indicate that all agonists used could mainly stimulate the acinar cells of the submandibular glands of the weanling rats which have already fully developed functionally at this time.

Bond strengths and pulpal response of light-cured composite resin inlays in primary molars.

The purpose of this study was to: 1) determine the most effective combination of composite resin and adhesive resin cement in the cementation process when fabricating esthetic inlays in severely broken down posterior primary teeth; 2) evaluate the pulpal response to adhesive resin cement in the primary teeth of young dogs. In Part I of the study, P-30 and Dentacolor composite resin inlays were evaluated with regard to their bonding strengths with Panavia-EX and Chemiace adhesive resins. Test samples of the composite resin inlays were prepared in molds according to the manufacturer's instructions. Each sample was polished on a flat, wet surface of 320 grit carborundum until a uniformly flat surface, perpendicular to the long axis of the cylinder was attained. Composite resin plugs, similarly fabricated, were bonded to the test samples using either Panavia-EX or Chemiace adhesive resin cements. A total of 160 samples were divided into four groups. Three of the groups were tested for bonding strength at intervals of 24 hours, 7 days and 30 days. The fourth group was thermocycled through 4 degrees C and 60 degrees C immersion periods. The results were analyzed using Tukey's studentized range test with an alpha (significance level) of 0.05. In Part II of the study, the pulpal response to Panavia-EX as a luting medium was compared with that of HY-Bond polycarboxylate cement. Cavities were prepared in 92 teeth from 8 young dogs and contralateral pairs of teeth were restored with Panavia-EX and HY-Bond polycarboxylate cement respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical evaluation of light-cured composite resin inlays in primary molars.

A study was carried out to evaluate the clinical potential of a visible light-cured composite resin inlay (P-30) cemented with an adhesive resin cement (Panavia-EX) in primary molars. The inlays were placed in Class I complex, Class II MO, DO, MOD and more extensive cavity preparations in primary molars. Fifty restorations were placed in 40 patients and evaluated at baseline, 3 months, 6 months, 1 year and 2 years. The evaluations were carried out according to the U.S. Public Health Service Clinical Rating System. The results showed the composite resin inlay cemented with an adhesive resin cement to be a highly effective combination.

Surgical exposure and orthodontic alignment of an unerupted primary maxillary second molar impacted by an odontoma and a dentigerous cyst: a case report.

This report describes the surgical and orthodontic management of a 3-year old girl with an unerupted primary maxillary second molar impacted by an odontoma and a dentigerous cyst. Following surgical removal of the odontoma and dentigerous cyst, further surgical intervention and orthodontic traction were required to bring the primary maxillary second molar into correct occlusion with resultant proper functioning and good periodontal health.

Effect of experimental fluoride-releasing tooth separator on acid resistance of human enamel in vitro.

This study aimed to investigate the fluoride-releasing ability of an experimental tooth separator consisting of polyurethane elastomer with tin fluoride and its effect on the acid resistance of human enamel. The tooth separator was set around an enamel slab and stored in de-ionized water for 10 days. The daily concentration of fluoride in the de-ionized water was measured. Then the enamel surface was artificially decalcified by a lactic acid buffer solution (pH 4.5) for 96 hours. The mineral density at the surface layer of the enamel was measured to evaluate the acid resistance. The fluoride release increased with the amount of fluoride in the separator, but decreased with the immersion time. Both the enamel area contacting with the separator and its surrounding area showed lower mineral loss and lesion depth compared with the controls (P < 0.05). It is suggested that the experimental tooth separator would release enough fluoride and improve the acid resistance of the enamel surface layer.

Clinical application of visible light-cured fluoride-releasing sealant to non-etched enamel surface of partially erupted permanent molars.

A visible light-cured fluoride-releasing sealant was applied to non-etched enamel surfaces of partially erupted permanent molars. A scanning electron microscope was used to find an effective procedure to clean pits and fissures of the occlusal surfaces prior to application of the sealant. This procedure proved clinically acceptable and effective for prevention of dental caries immediately after eruption of permanent molars.

Inverted impaction of second premolar: two case reports.

This report documents two patients with inversion and impaction of the second premolar tooth. Family and personal histories of both patients were unremarkable with no abnormalities in general growth and development nor any history of trauma. Patient 1 was a 10-year-old female with inversion and impaction of the mandibular right second premolar. Fifteen months previously, pre-operative radiographic examination prior to extraction of the mandibular right second primary molar revealed a normal direction and eruptive pattern of the tooth in question. However, following extraction of the mandibular right second primary molar, the developing succedaneous premolar was seen to be inverted. This was suggestive of inversion resulting from an iatrogenic force during tooth extraction. The second patient was a 9-year-old male with inversion and impaction of the maxillary right second premolar. Radiographic examination 3 months prior to the initial visit at our hospital showed an existing inversion of this tooth. This pointed to a developmental abnormality in the location of the original tooth bud.

Pulp and root development after partial extrusion in immature rat molars: a histopathological study.

Experimental studies were undertaken in immature rat molar teeth to investigate the relationship between root development and the prognosis after partial extrusion. The experimental partial extrusion was induced at 1/2 root formation, 2/3 root formation and 3/4 root formation, using an extrusion device designed by the author. Histopathological studies and SEM observation of the pulpal tissue in rat maxillary first molars with partially formed roots after partial extrusion were conducted and evaluated. The degree of extrusion was changed according to the development of the root to produce a similar luxated state. The rats were sacrificed immediately after experimental extrusion, immediately after operation, and after 3 days, 7 days, 14 days, 30 days, and 60 days to compare the histopathological and SEM findings between experimental groups and control groups. Immediately after the extrusive injury, ablations of the odontoblast layer from dentin were seen with retention of a fluid component in the ablated spaces in the pulp. On 1 and 3 days after surgery, cellular components such as erythrocytes and leukocytes due to bleeding were seen. Ablations of the odontoblast layer were seen in the coronal pulp most frequently in the pulp horn, cervical area and floor of the pulp chamber. In general, pulp reaction after extrusion in groups with more complete root formation was more severe than in groups with less complete root formation. It is suggested that the more complete the root formation, the greater the effect on the pulp as result of partial extrusion, while with less complete root formation, the greater the malformation of the root apices.

[A treated case of facial tic caused by a psychological factor. Successful case approached by psychosomatic dentistry].

As the oral psychosomatic diseases of infants appear connected with a predisposition of their environment, environmental adjustment and psychotherapy on the basis of psychosomatic dentistry are necessary in the treatment. We encountered a 9-year-old boy who seemed to be suffering from a facial tic caused by psychological factors. An attempt of therapy on the basis of psychosomatic dentistry was made in this case. The results as follows were obtained: 1. Intake interview to a mother was carried out regarding a cause of the tic. It was shown that the attitude of the mother will bring up the child and her meddling as well as the stress of school life caused his facial tic. 2. With our guidance, the mother reconsidered her meddling attitude toward the patient. And she was able to handle the patient with a kind attitude. 3. After play therapy as preparation, catharsis was carried out on the patient, the tic decreased rapidly. 4. Finally a token economy method was used. 5. It was thought that sufficient correspondence on the basis of psychosomatic dentistry was beneficial in the therapy of patient with psychosomatic disease in pedodontics.

The roles of the N-terminal portions of various tachykinins in promoting salivation.

OBJECTIVES: In order to determine the active sites for salivation of various tachykinins, the regulatory roles of the N-terminal portion of various newly-synthesized tachykinins were studied after i.p. injection of rats using the submandibular glands as model organs. METHODS: N-shortened oligopeptides from kassinin, eledoisin, neurokinins A (NKA) and NKB were synthesized by the multipin peptide synthesis method. Amino acids were eliminated one by one to form octa- to undeca-peptides adjoining the inactive or less active heptapeptides and various heptapeptides, in which an amino acid in position 8 (Xaa8), numbering as in an undecapeptide, was replaced with Tyr, Phe, Ile or Val. RESULTS: The N-terminal amino acids in positions 1 to 4 could be activators or inhibitors, depending on whether the C-terminal heptapeptide was inactive or less active. The Xaa8 residue, in combination with amino acids in positions 5 and 6, seemed to be very important in determining the sialogogic activity of a heptapeptide. The discrimination between NKA and NKB appeared due to the N-terminal amino acid sequence in positions I to 4 including Phe or Ser in position 6. CONCLUSIONS: It is concluded that the N-terminal amino acids in positions I to 4 serve as either activators or inhibitors depending upon the sialogogic activity of the C-terminal heptapeptide, in which particular amino acids in positions 5, 6 and 8 regulate its activity.

Idiopathic odontoma formation following avulsion of immature permanent incisors: two case reports.

From the findings of Case 1 and those cases reviewed in the literature it would appear that overfilling a canal with gutta percha prevents continued root formation after reimplantation of the tooth. The canal should be underfilled, therefore, if gutta percha is used as the obturating medium. Consequently, the authors recommend that calcium hydroxide be used as the root canal filling material of choice after reimplanting immature permanent teeth subsequent to traumatic avulsion. Since, however, calcium hydroxide paste tends to be resorbed, periodic refilling of the canal with the paste is required. Case 2 emphasizes the importance of periodic postoperative radiographic evaluation for several years after traumatic avulsion of immature permanent teeth.

[A supernumerary primary tooth inducing impaction of primary incisor: a case report].

A case of a primary supernumerary tooth in a 18 month old girl was reported. 1. The supernumerary tooth was located in the maxillary incisor area. 2. The maxillary left primary central incisor and the primary supernumerary tooth were impacted. 3. The clinical and radiographic findings indicated that the primary tooth in the mesial position was the supernumerary tooth, and therefore it was removed. 4. Three days after extraction of the mesiodens, the left primary central incisor erupted. The tooth completely erupted in two months. 5. The radiographic examination showed no supernumerary succedenous teeth.

A method of mixed dentition analysis in the mandible.

We developed a method of space analysis based on the fact that the measurement between the distal surfaces of the mandibular permanent lateral incisors was approximately equal to that of the combined widths of the mandibular permanent canine and premolars. This method is referred to as Interlateral Incisor Width (I.L.I.W.) Analysis. One hundred and nineteen Japanese children, without malocclusion, were selected for the study. Various measurements of teeth were taken in their mouths with a modified, fine-tipped, electrical, digital caliper and recorded in a Handheld Computer by connecting it to the caliper. Statistical analyses were conducted to compare the accuracy of the I.L.I.W., Ono, Moyers, and Ballard and Wylie analyses in the mandibular arch. The summary of the results were: Correlation coefficients for the sum of the actual mesiodistal dimensions of the canine and premolars with their predicted values obtained by each of the four analyses revealed r = 0.63 for I.L.I.W., r = 0.55 for Ono, r = 0.57 for Moyers, and r - 0.55 for Ballard and Wylie. Our I.L.I.W. method presented the best correlation of the four analyses, although each indicated a relatively low correlation. This method does appear to be clinically valid, since it is simple enough to enable the practitioner to estimate the combined dimension of the unerupted canine and premolars by measurement, in the mouth, of the distance between the distal surfaces of both mandibular permanent lateral incisors, instead of on study casts. It is recommended that a radiographic method be used in conjunction with our method to obtain a more accurate estimate.(ABSTRACT TRUNCATED AT 250 WORDS)

[Case report of three impacted supernumerary teeth in the premaxillary region].

A case is presented of a six-year-six-month-old boy with three impacted supernumerary teeth in the premaxillary region. The radiographic examination showed one mesiodens resorbing the root of the left primary central incisor and two inverted supernumerary teeth, also displacement of the unerupted permanent central incisors. Surgical treatment was performed to remove these supernumerary teeth. The forms of the mesiodens exhibited tubercularly shaped crown with four-conical cusp and two inverted supernumerary teeth showed a conicalshaped crown with incomplete root. According to the family history, a sibling had a supernumerary tooth in the same region which had been extracted in the past.

[Psychosomatic study on the relation between oral habits and personality characteristics of the children in a mountain village].

A statistical study was carried out to evaluate the circumstances of the oral habits of the children aged 3-15 yr. (423 boys and 379 girls, 802 children in total) in a mountain village through psychological tests and investigation of the living environments of children and their parents. The following results were obtained: 1. The peak age of finger sucking was 3 years with girls (35.7%) and 4 years with boys (22.2%). After these ages a tendency to decrease in frequency was observed. 2. The peak age of the nail biting was 11 years in girls (26.5%) and 10 years in boys (18.8%). However, the nail biting was observed in girls from infancy. 3. The peak age of bruxism was 7 years in boys (22.7%) and 4 years in girls (15.4%). 4. Based on sex, nail biting was found more with girls than with boys, on the other hand, bruxism was found more in boys than in girls. There was no difference in finger sucking. 5. Based on the analysis of the relationship between oral habits and personality characteristics, nail biting and bruxism showed a tendency towards a low percentile in almost all of the items of personality characteristics, however, scarcely any relationship was found in finger sucking. 6. Based on the analysis of quantification type III, the development of each oral habit showed a relationship to different personality characteristics. 7. In relation to the living environments, the nail biting occurred more in children whose mothers did not work than with those whose mothers worked, and bruxism occurred in the children who often play outdoors.

[An epidemiological study on dental caries of children in the town of Fuji].

An epidemiological investigation of dental caries was undertaken during the period of 1987-1989 with all children of nursery school, kindergarten, elementary and junior high school age in the town of Fuji, Saga prefecture which is a mountain villate, experiencing little movement of the population. From this investigation the following results were obtained. 1. Although the number of the children in each age group who had dental caries in deciduous and permanent teeth appeared to have decreased compared with 1987 and 1989, the dental caries prevalence in the children still remained high. 2. It appeared that it was important to give dental health education during the stage of immature young permanent teeth since there was prior to evidence of high dental caries in this stage. 3. The following was suggested for the improvement of caries experienced in immature young permanent teeth in the school in Fuji: (1) no stock of soft drinks in the refrigerator, (2) guardian's strict supervision of their children concerning snacks and, (3) acquiring of the habit of brushing during infancy and preschool years with parental assistance.

[An epidemiological study on dental caries of children in the town of Fuji. 3. Correlation between dental caries and personality characteristics].

A statistical study was carried out to evaluate the dental caries of permanent teeth in the elementary school children (208 boys and 165 girls, 373 children of total) in the town of Fuji, Saga Prefectur, which is a mountain village, by means of psychological test and investigation of the living environment of children and their parents. The following results were obtained: 1. In analysis of the relationship between the increase of dental caries and personality characteristics, was shown a tendency toward a low degree of direct of correlation. However, in analysis of quantification type III, it was proven that personality characteristics that as dependency, regression, nervousness and emotional instability related to an increase in dental caries. 2. In the analysis of the relationship between living environments and personality characteristics, a tendency towards a low personality profile was recognized in the children with an increase of dental caries. 3. In pasticvcal, there was a distortion of the personality characteristics of slef-uncontrol and dependency. 4. In comparing the first half of the elementary school year with the last half, a difference in the living environment and personality characteristics was observed during the last half year. 5. The results obtained in this study indicated that early discovery of problems in the living environment and synthetic approach during the first half of the elementary school year were important for the prevention of dental caries of permanent teeth.