Managing Iatrogenic Periodontal Disease

                                                  Figure 1

Periodontal disease has known etiological factors which include plaque and calculus which harbor bacteria. This multifactorial disease process is primarily a chronic inflammatory response to toxic bacterial byproducts which are the result of a lack of effective oral hygiene procedures. This is particularly true in cases of iatrogenically induced periodontal disease of the hard and soft tissue caused by restorations which violate  known biological principles.  Ill fitting restorations harbor plaque and calculus and frequently exhibit residual excess cement. The patient nor the clinician can accomplish effective oral hygiene which would maintain an acceptable level of gingival health.   Crown preparations which violate the biologic width,  are over contoured, and/or have uncleansible bridge or splint connectors cause chronic inflammation which destroys the supporting tissues.  Unfortunately, this damage cannot be treated with traditional soft tissue recontouring and/or adjunctive crown lengthening because of the disfiguring nature of these surgical procedures in the esthetic zone.  Advanced prosthodontic treatment of these difficult periodontal problems consists of four phases.  First and most importantly, removal of the offending restorations will create a healthier environment by  interrupting  the inflammatory cycle.  Each tooth must be cleansed of decay as well as residual cement before insertion of  an initial set of provisionals.   Excessive hemorrhage at this stage will preclude the fabrication of well fitting provisionals, so one can expect to  reline or remake these during the second phase of treatment until maximum healing has occurred. Only after the resultant tissues are free of active disease can one proceed with the third  phase of impressions and final restorations.  As you can see in Fig 1, these ill fitting crowns were splinted together without any biological indication.  Each crown’s margins extended  to the level of the supporting bone as did the connectors between each unit.  Healing during the provisional stage resulted in generalized flat gingival profiles with no bony defects and a gradual return to gingival health occurred over a 6 month period.  A decrease in gingival inflammation was characterized by an increase in tissue firmness and stippling. The final restorations in Figure 2 show the permanent loss of the interproximal  tissue resulting in “black triangles” which required careful handling in the final crowns. The irreparable disfigurement caused by poor tissue management only belies the high cost of reconstruction.  Even under the best of circumstances, continued tissue remodeling  with the associated gingival recession will occur most notably during the first year following insertion of the final crowns.  Use of translucent ceramic materials  help mask any exposure of the preparation margins in the esthetic zone. Increased prophylactic recalls are required during the maintenance phase of  patient’s in this category.

                                                              Figure 2