REMOVAL OF DENTAL CALCULUS REMAINS A MAJOR CONSUMER EXPENSE OF ORAL HEALTH CARE.

REMOVAL OF DENTAL CALCULUS REMAINS A MAJOR CONSUMER EXPENSE OF ORAL HEALTH CARE. PRODUCTS DESIGNED TO INHIBIT SUPRA- GINGIVAL CALCULUS FORMATION MAY HAVE ADVERSE EFFECTS ON HOSTMINERAL METABOLISM, AS BIOLOGIC CALCIFICATION OCCURS BY SIMILAR PROCESSES IN ANIMALS AND BACTERIA. DIPHOSPHONATES AND POLYPHOSPHATES ARE PARTLY SUCCESSFUL, AS THEY BLOCK GROWTH OF CRYSTALS; HOWEVER, THEY MAY NOT INHIBIT THE INITIAL DEPOSITION OF MINERAL. TOPICAL ANTIMICROBIAL SUBSTANCES REDUCE THE AMOUNT OF PLAQUE AND DELAY ITS MATURA-TION; HOWEVER, MICROORGANISMS ASSOCIATED WITH IMMATURE PLAQUE POSSESS THE ABILITY TO CALCIFY. THIS PROJECT WILL INVESTIGATE THE POTENTIAL OF INTERFERING WITH SYNTHESIS OF CALCIFIABLE PROTEOLIPID, A PROTEIN REQUIRED FOR INITIATION OF CALCIFICATION IN ORAL BACTERIA. IN PHASE I, THE GENE FORBACTERIONEMA MATRUCHOTII PROTEOLIPID WILL BE CLONED. TWO STRATEGIES WILL BE USED INVOLVING PRECIPITATION OF PROTEOLIPID-SPECIFIC MRNA USING ANTIBODIES AND/OR SYNTHESIS OF CDNA OLIGOMERS BASED ON THE PROTEIN AMINO ACID SEQUENCE. THE GENES WILL BE USED IN PHASE II TO IDENTIFY MECHANISMS FOR INHIBITING PROTEOLIPID SYNTHESIS. THIS APPROACH HAS THEADVANTAGE OF PREVENTING MICROBIAL CALCIFICATION WITHOUT ALTERING NORMAL HOST MINERALIZATION, AS GENE EXPRESSION IN EUKARYOTES AND PROKARYOTES DIFFERS.