Recurrence of mandibular molar furcation defects following citric acid root treatment and coronally advanced flap procedures.

This report concerns long-term (4 to 5 years) clinical evaluation of 22 resolved (complete bone closure) mandibular Class 2 furcation defects following coronally advanced flap procedures and citric acid root treatment with or without adjunctive implantation of freeze-dried, demineralized allogeneic bone. Sixteen buccal furcation sites in 12 patients were available for the follow-up evaluation. The furcation involvement was independently evaluated by a panel of three examiners, each using three furcation index systems. Oral hygiene standards, gingival health, probing depth, clinical attachment level, gingival recession, tooth vitality, and detectable caries or root resorption were also recorded. Mean attachment level at the furcation sites was 5.8 +/- 2.9 mm, compared to 4.5 +/- 2.2 mm and 3.5 +/- 1.3 mm over the prominence of the mesial and distal roots, respectively. The clinical examination further revealed that 12 out of 16 sites exhibited recurrent Class 2 furcation involvement. Of the 16 teeth examined, one had received endodontic treatment, while the remaining 15 responded within the normal range to pulp testing. One tooth had developed caries in the furcation region. No teeth demonstrated periradicular pathology. The results of this study question the long-term stability of furcation bone regeneration following coronally advanced flap procedures.

Periodontal repair in dogs: evaluation of the natural disease model.

Animal models are frequently consulted for histometric analysis of periodontal reconstructive therapy. Such models include surgical, periodontitis-simulating and natural disease defects in canines or non-human primates. Our studies suggest that homogeneity in defect height is critical for sensitivity of surgical and periodontitis-simulating supraalevolar defect models in discriminating treatment effects. We herein evaluate this model aspect for natural disease defects. Buccal-lingual histologic sections from the 2nd, 3rd, and 4th mandibular premolar teeth (P2, P3, P4) from 6 aged beagle dogs with advanced natural periodontal disease were used. Defect heights from the reduced alveolar bone to the cemento-enamel junction were recorded in central step-serial sections at the buccal and lingual surfaces of the mesial and distal roots for the premolar teeth. Mean defect height, standard deviation and coefficient of variation were calculated for tooth types and jaw quadrants, separately, and for all teeth. Confidence intervals were calculated for teeth in left and right jaw quadrants. Mean defect height and standard deviation for left and right jaw quadrants was 3.6 +/- 0.9 and 3.3 +/- 0.6 mm for P2, 3.3 +/- 0.9 and 2.3 +/- 0.9 mm for P3, and 3.3 +/- 1.0 and 4.5 +/- 1.6 mm for P4, respectively. Coefficient of variation for defects for left and right jaw quadrants was 26 and 40%, respectively. Using confidence intervals for mean differences between jaw quadrants, it was determined that a mean treatment effect may be as large as 0.8, 1.1 and 1.9 mm for P2, P3 and P4, respectively, before being detected as statistically significant (p < or = 0.05; N = 6).(ABSTRACT TRUNCATED AT 250 WORDS)

Periodontal repair in dogs: expanded polytetrafluoroethylene barrier membranes support wound stabilization and enhance bone regeneration.

A wound stabilizing effect of expanded polytetrafluoroethylene (ePTFE) membranes was evaluated in supra-alveolar periodontal defects in 5 beagle dogs. The defects, 5 to 6 mm in height, were surgically created around the 2nd, 3rd, and 4th mandibular premolar teeth in contralateral jaw quadrants. The root surfaces were conditioned with heparin, which, in this model, has been demonstrated to compromise periodontal healing and result in formation of a long junctional epithelium. Wound closure included application of ePTFE membranes around each premolar tooth in one jaw quadrant in each dog and flap positioning coronal to the cemento-enamel junction in both jaw quadrants. Healing progressed uneventfully except for 3 teeth in 2 dogs, which experienced membrane exposure. The dogs were sacrificed after a 4-week healing period and tissue blocks were prepared for histometric analysis. Connective tissue repair in heparin+membrane-treated teeth averaged 98% of the defect height compared to 84% in control heparin-treated teeth (P < or = 0.05). Junctional epithelium formation was smaller in membrane-treated teeth than in control teeth (P < or = 0.05) and was usually terminated coronal to the membrane. Bone regeneration was enhanced in membrane-treated teeth compared to controls (P < or = 0.01) and was strongly correlated to the area under the membrane in teeth without membrane exposure (r2 = 0.993; P = 0.002). This correlation was reduced when teeth with membrane exposure were included in the analysis (P < or = 0.05). Cementum regeneration was minimal under both treatment conditions. Root resorption was increased in membrane-treated compared to control teeth (P < or = 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Cemental tear related to rapid periodontal breakdown: a case report.

Cemental tears have been described both in exposed and unexposed cementum. The phenomenon is believed to be elicited by overloading or acute trauma from occlusion. In this case report a patient, with a history of periodontal health, presented with an acute periodontal lesion on the distal aspect of a bridge abutment tooth. Periapical radiographs demonstrated an extensive vertical intrabony defect adjacent to the vital abutment tooth containing a radiopaque "foreign body." Histological examination of the surgically removed "foreign body" revealed a piece of dental cementum with some attached soft tissue. The lesion responded well to a surgical approach. Healing was uneventful and periodontal health was restored. This case illustrates that cemental tear should be considered as a differential diagnostic entity in isolated sites with rapid periodontal breakdown.