Library

Notes: The fate of Salmonella infantis, Staphylococcus oureus, and Hafnia alvei inoculated onto vacuum packaged and polyvinylchloride (PVC) packaged fresh beef plate pieces after 0, 3, 7, 14, 21, and 28 days of storage at 1.7°C was investigated. Aerobic plate counts (APC's) of representative beef pieces were also monitored during storage and the effect of heat shrinking on both inocula and APC's in vacuum packaged samples determined. APC's of vacuum packaged beef pieces increased slower and attained lower final numbers than did PVC wrapped pieces. Levels of S. infantis in PVC and vacuum packaged samples declined at similar rates during 28 days of storage with overall decreases of 52 and 55%, respectively. The most rapid decreases occured during the first week of storage. S. aureus levels in PVC and vacuum packaged samples declined at similar rates during 28 days of storage with overall decreases of 90 and 80%, respectively. H. alvei increased in numbers by approximately 4.45 and 4.60 log cycles per gram in vacuum and PVC packaged beef pieces, respectively, during 28 days of storage. Levels of inocula in vacuum packaged samples were significantly lower initially and during storage than respective inocula in PVC packaged samples. Heat shrinkage of vacuum packages had no significant effect on levels of inocula or subsequent APC's.

Notes: This investigation was designed to test the co-destructive factor hypothesis that a traumatic lesion subjacent to marginal periodontitis alters the progression of the periodontitis and produces angular bony defects. Marginal periodontitis was produced around 28 mandibular teeth in 7 squirrel monkeys by tying a silk ligature at the gingival margin to facilitate plaque accumulation. Six months after inducing periodontitis a severe traumatic lesion was produced subjacent to the marginal periodontitis in 15 of these teeth by thermal injury via the root canal. These specimens (Group I) were analyzed from 3 days to 6 months after injury subjacent to the periodontitis. The duration of periodontitis in the remaining 13 teeth (Group II) was the same as Group I allowing a comparison between the groups. It was concluded that the presence of a severe traumatic lesion and its sequelae subjacent to a marginal periodontitis did affect the progression of the periodontitis when evaluated by apical migration of the junctional epithelium and loss of alveolar bone. Angular bony defects occurred only when periodontitis was induced around isolated tooth surfaces and were related to the presence or absence of the traumatic lesion. Angular defects may be related more to location of etiologic agent than a combination of co-destructive factors.

Notes: Two methods were used to induce gingival inflammation in squirrel monkeys (8 ovariectomized females and 3 males) with known levels of progesterone, estrogen and cortisol. Plasma progesterone and cortisol were assayed by a competitive binding technique. A bioassay of vaginal epithelium was used to assess estrogen activity. The ovariectomized animals were divided into two equal groups. Group I was injected with 10 mg progesterone and 0.2 mg estrogen twice daily for 50 days, producing elevated levels of these hormones. The remaining females (Group II) and the males (Group III) received vehicle for the same length of time. Regardless of the manner by which it was induced, gingival inflammation, as assessed by histometrics, was most severe in ovariectomized animals with no detectable progesterone and minimal estrogen (Group II). Group II, also, had lower levels of cortisol than the ovariectomized animals receiving progesterone and estrogen (Group I) and the males (Group III).

Notes: Octenidine, a new bispyridine mouthrinse, has been shown to prevent plaque formation in humans over a seven-day period. The purpose of the present study was to determine the effects of octenidine on plaque and gingivitis development in humans using a 21-day experimental gingivitis model. Eighty-eight subjects with a Plaque Index (PII) and Gingival Index (GI) ≤ 0.4 were randomly assigned to 4 coded formulations: 1) 0.1% octenidine in mouthwash vehicle used 3 times a day (TID), 2) 0.1% octenidine in mouthwash vehicle used twice a day (BID), placebo rinse once a day, 3) 0.1% octenidine in water used 3 times a day, and 4) mouthwash vehicle alone used 3 times a day (VEH). Each subject refrained from all mechanical plaque control and rinsed morning, noon, and evening under supervision with 15 ml of assigned formulation for 60 s. At 0, 7, 14, and 21 days, Pit, GI, and mucosal tolerance were assessed. Tooth stain was measured at day 0 and twice at day 21 (prior to and immediately following a single toothbrushing).By day seven of the rinse phase, significant mucosal irritation had occurred in several subjects in the octenidine in water group. Therefore, that group was discontinued from the study and the remaining 66 subjects continued. The mean PII increased in the VEH group from a mean of 0.13 at day 0 to 1.08, 1.39, and 1.69 at days 7, 14, and 21, respectively. In contrast, the mean PII of the TID and BID groups did not increase over the 21 day period (0.14 and 0.10, 0.18 and 0.22, 0.15 and 0.16, 0.12 and 0.16 at day 0, 7, 14, and 21 for TID and BID, respectively). Although the TID and BID groups did not statistically differ at any point, both groups demonstrated significantly less plaque accumulation than the VEH group at days 7, 14, and 21 (p 〈 0.000001). Gingivitis, as measured by GI, increased significantly in the VEH group from a mean of 0.14 at day 0, to 0.58, 0.84 and 0.98 at day 7, 14, and 21. Both the TID and BID groups demonstrated a small increase in mean GI, rising from 0.12 and 0.16 at day 0 to 0.21 and 0.24, 0.29 and 0.27, and 0.32 and 0.31 at days 7, 14, and 21 for TID and BID, respectively. Again, the TID and BID groups were not different while both had significantly less gingivitis than the VEH group at days 7, 14, and 21 (p 0.000002). Stain, observed in 26 subjects in the TID and BID groups at day 21, was removed by a single toothbrushing in all but 5 subjects. No significant adverse reactions were observed in the remaining subjects. These results demonstrate that octenidine, when used as the only means of oral hygiene for 21 days, will significantly inhibit the development of plaque and gingivitis.

Notes: Regeneration of cementum, ligament, bone and new attachment was achieved by introducing mixtures of recombinant human platelet-derived growth factor and insulin-like growth factor into debrided lesions of experimentally induced periodontitis in monkeys. This growth factor therapeutic regimen induced the regeneration of nearly 50% of the lost attachment within 4 weeks. New attachment in some cases included regeneration of horizontally resorbed interdental septa. These observations suggest that predictable, clinically significant gains in new attachment may be possible through the use of highly purified human recombinant growth factors delivered to debrided lesions of adult periodontitis in appropriate, inert carrier vehicles.