The aim of this study was to compare pain relief effects after periodontal flap operation between Nd: YAG laser irradiation and the administration of anti-inflammatory drugs in the same patients using the Visual Analogue Scale (VAS) .
Fifty-eight teeth in 10 patients were included in this study. The surgical procedure was as follows: the gingival flap was elevated, and root planing and bone defect debridement were done. In the experimental group (Exp) of 34 teeth in 10 patients, Nd: YAG laser was used to root surfaces, bone defects and the inside of gingival flaps after root planing and bone defect debridement (3.0 w, 30 seconds, 3 times) . In addition, this laser was irradiated around the mucogingival junction immediately after surgery (1.5 w, 1 minute, 3 times) . In the control group (Cont) of 24 teeth in 10 patients, no laser was applied following surgery. Every patient was given anti-inflammatory drugs after surgery as early as possible. VAS was performed immediately after surgery, at 1, 2, 3, 4, 5 and 6 hours in one day, and in the next day it was performed after the patients was waken up, at 1, 2, 3, 4, 5 and 6 hours.
The statistical analyses indicated that VAS of Exp was significantly higher than Cont from 3 to 4 hours in one day and there was no statistically significance in two days (p<0.05) .
This study suggested that Nd: YAG laser irradiation and anti-inflammatory drugs might have almost the same pain relief effect after periodontal flap surgery. Nihon Shishubyo Gakkai Kaishi (J Jpn Soc Periodontol) 48: 106-112, 2006.

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The periodontal ligament is exposed to mechanical stress such as occlusion, so periodontal ligament cells may have defenses against mechanical stress. We searched for the influence of mechanical stress on differentiation in HPDL cells, which were subjected to cyclic tension.
When HPDL cells were cultured under mechanical stress in normal medium, their ALP activity in stress groups was more inhibited than in control groups. The gene expression of periostin and Twist was an increased response to mechanical stress. BSP gene expression, a marker of osteoblasts, was not confirmed in stress or control groups. The calcium content in calcified materials produced after long-term culture was low. Results suggest that mechanical stress may accelerate differentiation of HPDL cells into periodontal ligament fibroblasts in normal medium.
BSP gene expression was firmed regardless of whether HPDL cells were cultured or not under mechanical stress in osteoblast differentiation medium. We thus expected that HPDL cells might differentiate into osteoblasts regardless of mechanical stress. When HPDL cells were subjected to mechanical stress in osteoblast differentiation medium, however, ALP activity increased and calcium content, a marker of calcification, increased more significantly in stress than in control groups. TGF-β1 gene expression was detected continuously in stress groups and the gene expression of periostin and Twist gradually decreased. This shows that HPDL cells under mechanical stress in osteoblast differentiation medium progress into differentiated osteoblasts.
These results show that when HPDL cells were differentiated into fibroblasts, mechanical stress may accelerate fibroblast differentiation, and when HPDL cells differentiated into osteoblasts, mechanical stress also may accelerate osteoblast differentiation. Nihon Shishubyo Gakkai Kaishi (J Jpn Soc Periodontol) 48: 113-122, 2006.

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We evaluated the effect of long-term maintenance on supportive periodontal treatment in private practice, mainly done by a dental hygienist. Subjects were patients-16 men and 24 women-with adult periodontitis. Following surgical or nonsurgical periodontal therapy in private dental practice, the dental hygienist conducted patient maintenance for 4 years. Subjects average 54.1 years of age (37-68 years) at the stage of primary care. Teeth initial by examined numbered 1,010. Clinical periodontal parameters were probing pocket depth (PPD) , bleeding on probing (BOP) , O'eary's plaque control record (PCR) , and furcation involvement. We also studied tooth survival and the relationship between restorative conditions and the clinical periodontal parameters. Marginal areas where PPD exceeded 5 mm or with acute periodontal abscess were marked as recurrent during maintenance. Clinical parameters were then examined at the endpoint of primary care, the starting point of maintenance, and each year of maintenance to years. During year 5 maintenance, PCR indices were continuously below 20%. No significant difference was seen in clinical PPD and BOP indices between the start of maintenance and years 1 to 5. No significant difference was seen in clinical parameters between treatment groups using surgical (N=14) and nonsurgical (N=26) procedure in maintenance. PPD was, however, greater in areas undergoing surgery than in the absence of surgery in subjects in the surgical treatment group (N=14) . Mean recurrence during maintenance was 2%. Obvious effects due to restoration of a tooth crown adjacent to periodontal tissue was not seen in any clinical parameters. Our data suggests that maintenance including a dental hygienist was effective in long-term maintenance of sustainable periodontal therapy in the clinic of a general dentist. Nihon Shishubyo Gakkai Kaishi (J Jpn Soc Periodontol) 48: 123-134, 2006.

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Gingival overgrowth is a common side effect associated with calcium channel blockers. We analyzed glycosaminoglycans (GAG) content in gingiva enlarged by nifedipine.
Gingival GAG were extracted from gingiva of 5 patients who taken nifedipine because of high blood pressure syndrome and experienced gingival enlargement (nifedipine group) and gingiva of 6 horizontal impacted teeth extracted from patients not taking nifedipine (control group) .
GAG was extracted from gingiva and separated by cellulose acetate membrane electrophoresis for qualitative and quantitative analysis. Results showed that GAG consisted mainly of hyaluronic acid (HA) and dermatan sulfate (DS) in gingiva, and HA was higher in the nifedipine group than in the control group.
These findings suggest that HA may be effective in gingiva enlarged by nifedipine. Nihon Shishubyo Gakkai Kaishi (J Jpn Soc Periodontol) 48: 135-141, 2006.

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We evaluate plaque control using a sonic toothbrush under instruction by dental hygienists. The 24 subjects—12 men and 12 women—were divided in 2 groups, one with and the other without instruction by dental hygienists, and their plaque control records (PCR) and time for plaque control using a sonic toothbrush after one week were compared. In the instructed group, mean PCR improved statistically from 44.1% before instruction to 27.5% after one week (p<0.01) . In the noninstructed (control) group, mean PCR changed from 46.2% to 40.8% and no statistical improvement was seen. Sites improved in the instructed group were mesial and distal, and improvements were 18.8%—65.8% before instruction and 47.0% after and 24.9%—61.7% before instruction and 36.8% after. These results indicated the efficacy of professional oral hygiene instruction by a dental hygienist in sonic toothbrush use. Nihon Shishubyo Gakkai Kaishi (J Jpn Soc Periodontol) 48: 142—148, 2006.

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