The use of the replica technique to record fluid emerging from exposed dentine.

The effect of pulpal cavity pressure on structures present on etched and unetched dentine was determined in 24 human premolars in vitro. The dentine was exposed in vivo. After extraction, the pulp was removed and the crown stored in 2.5 N sodium hydroxide for 3 days to remove the odontoblasts. The pulp cavity was filled with Ringer's solution at atmospheric pressure, +30 or -5 mmHg. After 30s-5 min a silicone-rubber impression was taken of the cavity floor and a resin cast prepared and examined in a SEM. The replicas reproduced the dentine surface accurately when there was no outward flow through dentine. With a pressure of + 30 mmHg in the pulp cavity, but not at the lower pressures, droplets were present on unetched dentine after 30s. Droplets accumulated less rapidly on etched dentine, indicating that it may act as a sponge.

Effect of smoking on periodontal health in molar teeth.

BACKGROUND: It is generally accepted that the primary cause of periodontitis is bacterial infection of long duration. In addition, there are several risk factors that may increase the probability and severity of periodontitis. For example, an increased breakdown of alveolar bone has been observed in smokers compared to never-smokers. The objective of this study was to investigate the association between cigarette smoking and periodontal health, in particular, furcation involvement in molar teeth. METHODS: One hundred twenty (120) adult regular dental patients, presenting with at least 20 teeth each, third molars excluded, were evaluated. Sixty of the subjects consumed an average (+/- SD) of 16.8 +/- 3.8 cigarettes daily and had smoked for 21.4 +/- 5.7 years. The remaining subjects presented a negative history of smoking. Periodontal conditions for the molar teeth were recorded at the first and second mandibular molar buccal furcation area. RESULTS: Oral hygiene standards and dental care habits did not differ notably between smokers and never-smokers. Smokers exhibited significantly fewer molar teeth than never-smokers (2.2 +/- 1.1 versus 3.0 +/- 0.8; P<0.01). Also, smokers exhibited significantly advanced gingival recession, probing depth, clinical attachment loss, furcation involvement, and tooth mobility compared to never-smokers (P<0.01). CONCLUSIONS: The results of this study suggest that long-term cigarette smoking significantly worsens periodontal health including degree and incidence of furcation involvement in molar teeth.

A clinical comparison of the new attachment obtained by guided tissue regeneration and coronally positioned flap techniques in the management of human molar furcation defects.

The present clinical trial was designed to evaluate the regenerative potential of the periodontal tissue in Class II furcation defects in mandibular molars using reconstructive surgery based on the guided tissue regeneration (GTR) technique versus the coronally positioned flap (CPF) technique. After the completion of the initial phase of therapy and four to six weeks healing period, 20 furcation-involved molars were examined for baseline data which included plaque index, gingival condition, probing depth (PD), probing attachment level (PAL-V, PAL-H) and radiographs. All parameters were reexamined after three, six and twelve months of healing, except PD, PAL-V and PAL-H which were not measured at three and six months. A nonparametric analysis was used. The study showed that there were no significant differences in the mean baseline measurements between the treatment groups. After 12 months following surgical treatment, both GTR and CPF procedures showed gains in new clinical attachment levels. When comparing parameters between the two surgical procedures, GTR molars showed significantly more improvement in probing depth as well as vertical and horizontal attachment level of the interradicular osseous defect than did the CPF molars (p < 0.05). About 80 per cent of the sites treated with the GTR technique showed complete clinical resolution of the furcation problem. CPF therapy reached the same Treatment goal in about 50 per cent of the cases which were treated. Guided tissue regeneration appeared to be more effective in promoting regeneration than the coronally positioned flap.

[Periodontal new attachment therapy].

The ultimate goal of periodontal therapy includes not only the arrest of progressive periodontal disease, but also the restitution of those parts of the supporting apparatus which were destroyed by the disease. Regeneration of periodontal structures dissolved because of periodontal disease is the goal of reconstructive periodontal treatment procedures. The achievement of this goal requires the formation of new cementum with inserting collagen fibers of previously periodontitis involved root surfaces possibly with a concomitant regeneration of supporting alveolar bone. Healing, after periodontal therapy, leads to the formation of long junctional epithelium, root resorption, ankylosis, etc. These are repair process and not one of regeneration. But guided tissue regeneration seems to lead to regeneration with active periodontal ligament cells.

[Corticotomy--facilitated orthodontics].

Incorporating a surgical procedure with orthodontics makes it possible to complete treatment in a shorter period of time due to the ability to more rapidly move teeth. Corticotomy-facilitated orthodontics is a method of treatment that has the potential to greatly decrease the time involved and increase the quality of orthodontic services to the adult patient. The corticotomy procedure is a surgical technique in which a fissure is made through the cortical plate of bone that surrounds a tooth. The tooth is in a block of bone that is connected to other teeth and structures only through the medullary bone. This procedure claims that the teeth are more stable after this type of treatment may be due to less disruption of the periodontal ligament by osteoclastic activity and/or that the callus formed as bone heals leads to greater stability.

The effect of a dentifrice containing soluble pyrophosphate and a copolymer on calculus deposit: a six-month clinical study.

A six-month, double blind, cross over clinical study was conducted to compare the effect of a commercially available anticalculus dentifrice and a placebo dentifrice on supragingival calculus deposits. Fifty adult subjects who entered the study were given an oral prophylaxis and were assigned to use either pyrophosphate/copolymer toothpaste or a placebo toothpaste for a period of three months. They were then scored for calculus deposits using the Volpe-Manhold method, received a second oral prophylaxis and used the alternate dentifrice for a second three month period of time. The subjects were again scored for calculus deposits and the study was completed. The results indicated that pyrophosphate/copolymer toothpaste reduced supragingival calculus formation by 37.07%, as compared to the placebo dentifrice. This reduction was significant at the 99% level of confidence.