Response properties of periodontal single afferents were investigated in cats with inflammatory irritant-induced pulpitis. A deep dentin cavity was prepared on the right mandibular canine in order to apply an inflammatory agent and small fiber excitant, allyl-isothiocyanate (mustard oil : MO), and single afferents innervating the canine periodontal mechanoreceptor were dissected from the mandibular nerve bundle by examining impulse responses while applying mechanical stimuli to the tip of the crown. Evoked impulses by mechanical stimuli were increased in number for 15 minutes with MO application to the pulp when compared with those with mineral oil. The mechanoreceptive thresholds of single nerve fibers were decreased after the MO application to the pulp when compared with those with mineral oil. These results suggest that the alteration of responses in the periodontal afferent fiber, or the peripheral sensitization, can be produced by MO-induced pulpal inflammation probably due to the axon reflex mechanism in the furcating branches of nerve fibers innervating both the tooth pulp and periodontal ligament.
Although highly concentrated hydrogen peroxide (HP) has been used to bleach vital discolored teeth during office whitening, low-concentration HP was recognized to have insufficient whitening ability. We demonstrated that using a visible light-responsive titania photocatalyst (VLRTP) and a vis-Nd : YAG laser, 3 wt% HP-bleached oxytetracycline (OTC) -stained teeth models were more efficient than 30 wt% HP. The stained samples were prepared by soaking synthetic hydroxyapatite ceramic disks in OTC aqueous solutions. Color images of the OTC-stained models before and after whitening were taken with a conventional flatbed scanner and calibrated using a photocell colorimeter. By VLRTP treatment with vis-Nd : YAG laser irradiation, the lightness value (L*) significantly increased and the yellowness index (b*) significantly approached zero. This suggests that a diluted HP agent with VLRTP can more efficiently decolorize stained teeth by visible light irradiation.
The purpose of this study is to measure the morphology of the nose and lip of unilateral cleft lip/cleft lip and palate (UCL/UCLP) patients with a three-dimensional (3-D) digitizer before and after secondary cleft lip and nose repair, and to compare them with normal adults, as well as to investigate the effectiveness of philtrum plastic surgery. This study includes 21 UCL/CLP patients who received the same operation. We used 12 normal adults as the control group. We took facial impressions at the time of pre-operation and six months after operation, and constructed the models using hard plaster. These plaster casts were used as materials in this study. The control materials were also made from normal adults in the same manner. All the measurements were taken using calipers and the depth of the philtral dimple was measured with a 3-D digitizer. The distance between the inside of the eye and the alar base, the distance between the bilateral alar bases, the distance between the columella base and the alar base were measured. The length of philtrum ridge showed obvious signs of improvement, and was almost the same as normal adults after our surgical approach. The width of the philtrum and the depth of the philtral dimple of UCL/CLP patients were improved after secondary cleft lip and nose repair. However, further treatment is still essential for better aesthetics and recovery.
The association between phenytoin-induced gingival hyperplasia (PIGH) and five major periodontopathic bacteria was investigated by real-time PCR in 12 subjects (30.6±7.95 years of age) with severe motor and intellectual disabilities. The subjects had not received antibiotics or periodontal therapy within three months. A healthy gingival site or a site with the lowest gingival hyperplasia score (minimum site), and a site with the maximum score of gingival hyperplasia (maximum site) on each subject were selected for investigation. The clinical parameters were measured after microbial sampling.
The following results were obtained :
1. The detection rates of both Treponema denticola and Porphyromonas gingivalis were 75% (9/12) at the maximum sites, and that of Tannerella forsythia was 33.3% (4/12). The detection rate of Prevotella intermedia was 58.3% (7/12), but no significant correlation was observed between this bacterium and the other types of bacteria in quantitative analysis.
2. The detection rate of P. gingivalis with typeⅡ fimA was 25% (1/4) at the minimum sites, and 83.3% (5/6) at the maximum sites.
3. The samples were divided into three groups ; namely, those with no detection of P. gingivalis at either the minimum sites or the maximum sites, no detection at the minimum sites but detection at the maximum sites, and detection at both sites.
In conclusion, 1) the detection rates of T. denticola and P. gingivalis were the highest at the maximum sites. In particular, the detection rate of P. gingivalis with typeⅡ fimA was high in the present study, and 2) the subgingival microflora was diverse because of the diverse severity of gingival inflammation associated with PIGH.
The purpose of this study is to state the clinical and colorimetric features of pigmented lesions on oral mucosa. Among 201 pigmented lesions on oral mucosa, there were 74 melanin pigmentations (36.9%), 72 exogenous pigmentations (35.8%), 28 pigmented nevi (13.9%), and 27 malignant melanomas (13.4%). Melanin pigmentations were found mainly on the gingiva and lip, exogenous pigmentations were on the gingiva, pigmented nevi were found on the buccal mucosa, and malignant melanomas were on the upper gingiva. Thirty-six pigmented lesions were measured by colorimeter, and each lesion was evaluated numerically using the CIE L*a*b* colorimetric system. The statistical significance was confirmed by Tukey's test and a p value<0.05 was assumed as a significant difference.
The color distribution of melanin pigmentation and exogenous pigmentation and malignant melanoma were significantly lower than normal mucosa in L*. A statistical significance was found between each pigmented lesion and normal mucosa in a* and b*. Among malignant melanoma and melanin pigmentation or exogenous pigmentation, a statistical significance was found in a* and b*. The color difference between melanin pigmentation and malignant melanoma was significant. The color distribution is thought to be different in each pigmented lesion, and we suggest that it is useful to use colorimetric features to diagnose each pigmented lesion.