Clinical Observation Of Gingival Biotype And Morphology Effect On Presaturated Gingival Retraction Cords

Objective: Utilizing digital single lens reflex and three-dimensional model analysis to evaluate gingival recession(GR)of free gingival margin after using presaturated retraction cords(with 8% epinephrine),which are affected by different gingival biotype and gingival morphology(thin gingival biotype/scalloped gingival,thick gingival biotype/flat gingival,thick biotype/scalloped gingival).Methods: Gingival retraction was studied in 30 participants at random.They were divided into three groups: thin gingival biotype/scalloped gingival,thick gingival biotype/flat gingival,and thick biotype/scalloped gingival.Gingival retraction was photographed every 3 seconds from 0 to 180 seconds after removal of the cord.The gingival retraction was measured at the mesial,mid and distal buccal on digital image,using computer software(Photoshop CS6,Adobe).Using the same way to choose participants.Intraoral optical impressions were performed before and after(immediately,7,and 14 days)gingival retraction.The 3D models obtained after gingival retraction were superimposed with the 3D models obtained before gingival retraction by Geomagic Qualify 2013 software and the GW and GR(immediately,7 and 14 days)of different groups were compared.Result: all groups' mid smallest GR is larger than mesial and distal(P<0.05),and mesial and distal had no significant difference(P > 0.05).thin gingival biotype/scalloped gingival smallest GR is larger than other groups(P < 0.05),and there were not statistically different between thick gingival biotype/flat gingival and thick biotype/scalloped gingival.The thin gingival biotype/scalloped gingival GR0(0.542±0.107m)is the largest(P<0.05),but there had not significantly difference between other two groups(P>0.05).The thin gingival biotype/scalloped gingival GR7 is the largest(0.200±0.035mm),followed by thick biotype/scalloped gingival GR7(0.118±0.029mm),thick gingival biotype/flat gingival GR7 is minimum(0.072±0.023mm)(P<0.05).thin gingival biotype/scalloped gingival GR14 is largest(0.263±0.032mm),followed by thick biotype/scalloped gingival GR14(0.175 ± 0.022mm),thick gingival biotype/flat gingival GR14(0.116±0.015mm)is minimum(P<0.05).The thin gingival biotype/scalloped gingival and thick biotype/scalloped gingival were both presented as GR0 > GR14 > GR7(P < 0.05),but thick gingival biotype/flat gingival GR0 is largest(P<0.05)and there had no significantly difference between GR7 and GR14(P>0.05).Conclusion: The thin gingival biotype/scalloped gingival GR is larger than thick biotype/scalloped gingival and thick gingival biotype/flat gingival,and in clinically,the crown of thin gingival biotype/scalloped gingival patient should use supragingival margin or evenginival margin.