Histological study of therapy for infected nonvital permanent teeth with incompletely formed apices.

The histological response of periapical tissues to root canal fillings with calcium hydroxide (Ca(OH)2)-iodoform paste, Vitapex (Neo Dental Chemical Products Co., Ltd., Tokyo, Japan), and Ca(OH)2-camphorated paramonochlorophenol (CMCP) paste in nonvital permanent teeth with incompletely formed apices was investigated in 160 root canals from 90 dog premolar and incisor teeth. Periapical inflammatory lesions were initially induced in the experimental teeth. After debridement and cleaning, root canals were filled with one of the two materials. The animals were sacrificed after 30, 60, 120, or 180 days, and histological sections of each specimen were prepared with hematoxylin and eosin staining. Histological findings showed periapical repair and apical closure in both experimental groups. However, the differences in the level of inflammation, apical closure, and reparative process among the two groups were significant (p less than 0.05). It was concluded that the Ca(OH)2-iodoform paste, Vitapex, produced better results than Ca(OH)2-CMCP paste in treatment of infected nonvital permanent teeth with incompletely formed apices.     

Topical chemotherapy in human periodontitis using a new controlled-release insert containing ofloxacin. I. Microbiological observation

The recognition that destructive periodontal diseases may be caused by specific microorganisms in periodontal pockets has led to an increased interest in and usage of antimicrobial agents in periodontal therapy. Recently, a new controlled-release insert containing ofloxacin, a synthetic antibiotic, has been developed. In this study, the controlled-release insert (PT-01) was microbiologically evaluated in combination with or without subgingival mechanical debridement. PT-01 was applied in the periodontal pockets of 27 patients with chronic periodontitis. Three sites with a deep probing pocket depth (greater than or equal to 5 mm) were randomly selected in different quadrants of each patient, and were assigned into three groups, i.e., PT-01 applied (T), placebo applied (P) and control sites (C). Periodontal treatments consisted of supragingival scaling with oral hygiene instruction for the first 2 weeks followed by root planing and subgingival scaling PT-01 was applied weekly on day 0 to 35, and the subgingival plaque samples from each site were collected on d 0, 14, 21 and 42. The dynamics of the subgingival microflora was investigated by dark field microscopy and by anaerobic and aerobic cultivation. In the supragingival scaling period, significant reduction in percentages of spirochetes and motile rods and significant increase of the percentage of coccoid cells were observed only at T sites. In addition, the total viable counts of bacteria, black-pigmented Bacteroides and Fusobacterium species were significantly reduced at T sites. After mechanical subgingival debridement, significant shifts in the proportion and reduction of the viable counts in the subgingival microflora were found at all sites.(ABSTRACT TRUNCATED AT 250 WORDS)     

Tooth length determination: a review

Tooth length determination is a crucial step in endodontic treatment. Until the late 1970s, tooth length determination was based mainly on radiographic interpretation. The advent of apex locators, which identify the difference in the electrical resistance between the root canal and the periodontal membrane, ushered in a new era for measuring tooth length. However, the accuracy of these devices has been questioned. Pertinent literature is discussed with the aim of providing information on the development of the concept, techniques, and devices for tooth length determination.     

Effects of zinc oxide-eugenol on leucocyte number and lipoxygenase products in artificially inflamed rat dental pulp

The number of leucocytes and level of endogenous LTC4 in the pulp tissue were measured by a histological method and radioimmunoassay, respectively. When the mandibular incisor pulp was irritated by drilling a hole in the dentine without using any coolant, the number of polymorphonuclear leucocytes and lymphocytes and the concentration of LTC4 increased to 3.2, 1.9 and 1.8 times their respective levels in normal pulp 6 h after the injury. The total leucocyte number in blood collected from these rats was also increased significantly. In contrast, when the cavities cut in dentine were filled with a zinc oxide-eugenol mixture (powder: liquid 100 mg/25 microliters), the increase in the number of cells was significantly curtailed, and the LTC4 level fell to 50% of that in normal pulp within 1 h after the filling. No decrease in the LTC4 level was observed after filling with a zinc oxide-water mixture, but the level decreased in response to an increase in eugenol content in the zinc oxide-eugenol placed in the cavity. Biosynthesis of [14C]-HETE and HPETE from [14C]-arachidonic acid was inhibited by the addition of 10 microM eugenol to the pulp homogenate. Thus eugenol released from zinc oxide-eugenol inhibited the biosynthesis of lipoxygenase products and the early chemotactic accumulation of leucocytes.     

A case of undifferentiated carcinoma arising in the mandible

A case of undifferentiated carcinoma arising in the minor salivary gland is reported. Preoperative chemotherapy, surgery and postoperative immunotherapy were performed and good results were obtained for 15 months after surgery. However, metastasis to the lung occurred 18 months after surgery. The histologic diagnosis, clinical findings and origin of this tumor are discussed.     

Osteochondroma of the coronoid process of the mandible. Report of a case showing histological evidence of neoplasia

A case of unilateral enlargement of the coronoid process of the mandible is presented. The patient, a 37-year-old woman complained of restricted mandibular movement and swelling in the left zygomatic region. Coronoidectomy was performed intraorally, producing improved mandibular movement. The specimen consisted of a large amount of cartilage and mature bone. Most of the cartilage showed a marked disturbance in endochondral ossification. The histopathological diagnosis was osteochondroma. A review of the basic nature of the disease in the reported cases is presented. The value of computed tomography in deciding on a surgical procedure is briefly mentioned.     

Clinical significance of serum acid soluble glycoproteins (ASP) and immunosuppressive acidic protein (IAP) in inflammatory diseases and liver diseases

In order to study the clinical significance of ASP and IAP, we have measured serum concentration of ASP and IAP in 259 patients with inflammatory diseases, non-inflammatory diseases, autoimmune diseases and liver diseases. Significantly higher correlation (coefficient of correlation = 0.922) was found between ASP and IAP. There were good correlation between ASP, IAP levels and erythrocyte sedimentation rate (ESR), C-reactive protein (CRP). Coefficient of correlation were 0.705 and 0.673 between ESR and ASP, IAP; 0.621 and 0.623 between CRP and ASP,IAP, respectively. There were food correlations between ASP levels and thrombo test (TT) and hepaplastin test (HPT). The positive rate and mean concentration of ASP, IAP in patients with inflammatory diseases were significantly higher than noninflammatory diseases. It is suggested that serum ASP, IAP could be one of the useful indicator for evaluating the clinical course of patients with inflammatory diseases. Serum concentration of ASP, IAP in patients with chronic liver diseases were lower than normal subjects, especially serum levels in patients with decompensated liver cirrhosis and chronic hepatitis (active) were significantly lower than normal subjects. In patients with hepatoma with cirrhosis, serum levels of ASP, IAP were significantly lower than the hepatoma patients without cirrhosis. The determination of ASP, IAP in liver diseases seems to be useful for evaluating the severity of diseases, the effects of therapy and the forecast of prognosis.     

Clinical evaluation of the GaALAs laser treatment for hypersensitive dentin

The methods available for treatment of hypersensitive dentin include the application of heavy metal salts such as diamine silver fluoride to the tooth, iontophoresis, Hyper-Band patching and restoration with various filling materials following cavity lining. Laser beam therapy, which has recently been used in dental treatment, is also expected to be applied to the treatment of hypersensitive dentin. In the present study, we obtained interesting results from the clinical use of a GaAlAs semiconductor Laser (Semilaser Nanox LX-800, GC Co.). The subjects were 63 patients with hypersensitive dentin: 8 patients without the exposed root, 40 with the exposed root, 21 treated with filling materials, 5 given Hyper-Band treatment, 14 with wedge-shaped defect, attrition or abrasion, and one with primary caries. Twenty-six fell into two or more categories. The effect of treatment was assessed by a single examiner in order to minimize error of estimates. Each lesion was directly irradiated for less than 3 minutes, and assessment of the result was conducted according to the criteria and method of Suzuki and Ishikawa. The results were as follows: The treatment was markedly effective in 44 (69.8%), effective in 12 (19.0%) and not effective in 7 (11.1%) of 63 patients. No case of exacerbation was found. The efficacy rate was 88.9%.     

Microscopic and crystallographic examinations of the teeth of the X-linked hypophosphatemic mouse

Teeth from the C57BL/6J-Hyp mouse (Hyp mouse) were examined histologically, radiographically, and crystallographically. Microscopic examinations of the ground sections, the decalcified and H-E-stained sections, and the contact microradiograms of molars and incisors from the Hyp mouse showed several abnormalities--such as large pulp chamber, wide predentin, thin dentin at the pulp floor, and multiple occurrences of interglobular dentin. Powder and microbeam x-ray diffraction analyses showed that the crystallinity of hydroxyapatite in incisor globular dentin from the Hyp mouse was higher than that in incisor dentin from the normal mouse. On the other hand, the findings of transmission electron microscopy demonstrated that the sizes of hydroxyapatite crystals of globular dentin in the Hyp incisor were larger than those in normal incisor dentin. These results demonstrated that the findings in Hyp mouse teeth were in accord with those of human XLH teeth.     

Clinical evaluation of serum immunosuppressive acidic protein (IAP) and acid soluble glycoproteins (ASP) in patients with malignant tumors

In order to study the clinical significance of IAP and ASP, we have measured serum concentration of IAP and ASP in patients with different cancer types including digestive organs, head and neck. Significantly higher correlation (coefficient of correlation = 0.924) was found between IAP and ASP. IAP and ASP levels were elevated in about 60-80% of cancer from digestive organs except hepatocellular carcinoma, and in about 56-100% of head and neck tumor. There was no correlation between IAP, ASP and various tumor markers (CEA, CA19-9, AFP) in all malignancies except pancreatic cancer. There was positive correlation between CEA and IAP, ASP in pancreatic cancer. IAP and ASP levels were significantly higher in patients with cancer having evidence of disease than the patients with cancer who had no evidence of disease, and so the determination of IAP and ASP was clinically useful for the diagnosis of tumor existence. At the time of diagnosis of recurrence, the levels of IAP and ASP were elevated in about 70% of patients with cancer recurrence. There was a definite relation between IAP, ASP and the gastric cancer stage. In later state (stage III and IV), serum IAP and ASP levels were significantly higher than the levels of stage I and II. In hepatocellular carcinoma without liver cirrhosis, the levels of IAP and ASP were higher than the patients with cirrhosis. The determination of IAP and ASP seems to be useful for monitoring clinical course, judgement of therapeutic effects.