前牙美学之牙龈生物型课件

Anterior dental aesthetics: Gingival perspective Thin periodontal biotype Periodontal biotype is classified as thin, normal or thick Thick periodontal biotype 1. Thin periodontiumthickness of attached gingival less than 1 mm, width3.55 mm, thin marginal bone 2. Thick periodontiumthickness of attached gingival to 1.3 mm, width 56 mm and more, thick marginal bone The thick biotype with its flattened gingival soft tissue form tends to be more frequent with it occurring in 85% of the population than the thin biotype with its scalloped tissue form (15% of the population). Characteristics of thin biotype (a) Highly scalloped soft tissue and bony architecture (b) Delicate friable soft tissue (c) Minimal amount of attached gingiva (d) Thin underlying bone characterized by bony dehiscence and fenestration (e) Reacts to insults and disease with gingival recession Characteristics of thick biotype (a) Relatively flat soft tissue and bony architecture (b) Dense fibrotic soft tissue (c) Relatively large amount of attached gingiva (d) Thick underlying osseous form (e) Relatively resistant to acute trauma (f) Reacts to disease with pocket formation and infrabony defectformation Firstly, the thin gingival margins allow visibility of a metal substructure. Secondly, due to the fragility of the thin tissue, delicate management is essential for avoiding recession and hence visibility of subgingivally placed crown margins at the restoration/tooth interface a thin biotype the degree of interproximal fill is also dependant on the periodontal biotype A thick periodontal biotype encourages interdental fill, while a thinner tissue type creates un-aesthetic hollow gingival embrasures. For thick biotypes, the papilla may be established to normal dimensions of 5 mm, but for thin biotypes, it is difficult to recreate a papilla longer than 4 mm from the osseous crest The 5 mm rule is only applicable for adjacent natural teeth or implants bounded by natural dentition. “5 mm rule” Normal scallop periodontal bioformHigh scallop periodontal bioform Low or flat scallop periodontal bioform Periodontal bioforms are categorised into three basic gingival scallop morphologiesCause? With a low scallop, the interproximal bone is thin, and the interproximal gingival contour nearly parallel to the underlying bone contour. The normal is advantageous for implant therapy since the bone has a congruous relationship with the FGM and is less prone to post-surgical recession. With a high scallop, the interproximal bone is wider, but the disparity between the bone contour and the FGM is problematic for favourable aesthetics (due to possible recession and creation of lack triangles) following implant or restorative procedures. TOOTH MORPHOLOGY Tooth morphology determines two aspects of gingival undulations Firstly, the basic tooth forms: circular, square or triangular, determine the degree of gingival scallop. Circular (oval) or square teeth produce a shallower gingival scallop, while triangular teeth form the opposite, a pronounced scallop black triangles, especially with a thin biotype which has a propensity for recession, thicker interproximal squarer teeth yield better interproximal papilla maintenance due to a smaller interproximal distance from the osseous crest to the FGM. For square-shaped teeth with wide contact points, the chances of black triangles is minimal compared with triangular teeth having narrow, more incisally positioned contact points Secondly, the convex acuity of a tooth circumference influences the coronal/apical position of the FGM convex tooth a concave shape TOOTH POSITION AND GINGIVAL PROGRESSION Altered passive eruption on the maxillary right lateral incisor Bucally placed maxillary left lateral incisor with an