Roland M. Meffert

The pulpal response to topically applied citric acid.

Citric acid is currently being used to aid in the reattachment of periodontal tissues to tooth roots which have become separated as a result of periodontitis. The present study examines the effect of topically applied citric acid on the dental pulp. Citric acid, pH 1, was applied for 3 minutes on instrumented premolar teeth in six dogs. As a control, saline solution was applied on similarly instrumented premolars. The teeth were removed 1, 6, 24, 48, 72, and 144 hours after citric acid application. After histologic preparation, the pulps were examined for inflammatory cell infiltrates, odontoblast displacement into the dentinal tubules, hyperemic capillaries in the odontoblast layer, hemorrhage, abscess formation, irregular dentin, and the thickness of the dentin remaining beneath the treated area. There was no statistically significant response to the citric acid over the saline controls. Nor was the pulpal response, as examined above, correlated to the thickness of the remaining dentin. The results suggest that citric acid, pH 1, when applied to tooth roots during surgical reattachment therapy, does not adversely affect the pulp.

Ceramic-coated implant systems.

Practitioners have used hydroxyapatite-coated (HA-coated) endosseous and subperiosteal implants in various forms for many years. These have included root forms in both screw and cylindrical shapes, blades, and subperiosteals. The clinical predictability remains controversial and subject to claims and counterclaims. The early days of dental implantology involving root-form implants recommended their placement in fully edentulous cases only, and anterior to the maxillary sinus and mental foramen. Todays philosophy and rationale of dental implantology include the placement of a single implant replacing a missing natural tooth (especially where the teeth adjacent to the edentulous site have no caries or restorative experience). Implants are used to replace the natural dentition in one quadrant/segment, often preceded or accompanied by ridge augmentation and/or sinus grafting if sufficient bone is not present. So we have to address the clinical predictability of survival in terms of indications, quantity, and quality of bone. Clinical data and experience suggest that hydroxyapatite-coated (HA) dental implants may (and possibly should) be used in (1) Type IV bone, (2) fresh extraction sites, (3) grafted maxillary and/or nasal sinuses, or (4) with short implants (≤ 10 mm in length).