Study On RANKL、OPG In Gingival Crevicular Fluid Of Mesial Impacted Mandibular Third Molars

ObjectiveIn this subject it choosed absorbent paper points to collect the gingivalcrevicular fluid (GCF) of mesial impacted mandibular third molars, in order totest contents of receptor activator nuclear factor kappa B ligand (RANKL) andosteoprotegerin(OPG). It is discussed that what are effects of mesial impactedmandibular third molars on periodontium nearby when without inflammation, forthe purpose to provide theoretical evidence for prophylactically pulling outmesial impacted mandibular third molars in the clinical.Methods1. Comparing three kinds of materials of collecting GCF:30th absorbentpaper points for10mm long, Whatman I filter paper for2×10mm long andWhatman III filter paper are selected to study protein contents and elutionprotein concentration, which used BCA in vitro.2. Cases selection and test in groups: A total of48patients, diagnosed asmesial impacted mandibular third molars and16patients, diagnosed asnon-mandibular third molar who come to dentistry, in the hospital from march toDecember in2011. Conclusion standards of mesial impacted mandibular thirdmolars are that it is during5-85o between mandibular third molars and adjacentteeth under X-ray. Conclusion standard of periodontitis is gingival bleedingindex which is greater than3. The groups as follow: Group A is mesial impactedmandibular third molar, whose gingival is healthy and has no pericoronitis;Group B is mesial impacted mandibular third molar, whose gingival is healthybut has pericoronitis history in six months; Group C is mesial impacted mandibular third molar which has pericoronitis; Group D is non-mandibular thirdmolar, which is the control group.3. Test of the GCF: It chooses ELISA to test contents of RANKL and OPG.Results1. Comparing protein contents of three kinds of materials of collecting GCF:30th absorbent paper points for10mm long, content0.126±0.01ug/ml;Whatman I filter paper for2×10mm size, content0.122±0.01ug/ml; Whatman IIIfilter paper for2×10mm size, content0.125±0.01ug/ml. The comparing resultshas no obvious difference(P>0.05).2. Comparing elution protein concentration after absorbing protein of threekinds of materials of collecting GCF:30th absorbent paper points for10mm long,content3.42±0.71ug/ml; Whatman I filter paper for2×10mm size, content3.18±0.76ug/ml; Whatman III filter paper for2×10mm size, content3.45±0.80ug/ml.Differences of the results have no statistical significance（P>0.05).3. Comparing Group C and GroupA,B: it is showed that RANKL(88.42±4.63pg/ul) in GCF in Group C is higher than Group A (75.59±2,87pg/ul) andGroup B (78.11±2.08pg/ul), which has the statistical significance(P<0.05). OPGin Group C(71.24±2.75pg/ul) is higher than Group A（67.15±1.78pg/ul) andGroup B (68.18±2.14pg/ul), which has the statistical significance(P<0.05). TheRANKL and OPG in Group A and Group B are not obvious difference, whichhave no statistical significance（P>0.05).4. Comparing Group A, B and the control group: Contents of RANKL inGroup D(36.61±2.69pg/ul) is obvious lower than Group A and B, which has thestatistical significance(P<0.05). But contents of OPG(77.18±1.78pg/ul) is higherthan Group A and B, which has the statistical significance(P<0.05).5. Comparing RANKL/OPG: RANKL/OPG in Group D(0.47) is apparentlylower than Group A(1.14) and Group B(1.15), Group C(1.15), which has thestatistical significance(P<0.05). Group C is higher than Group A and Group B,which has the statistical significance(P<0.05). There is no obvious differencebetween Group A and Group B(P>0.05). Conclusions1. All the three materials can be used to collect GCF. But absorbent paperpoint has a smooth shape and is prepared easily, which is not easy to hurtgingival but easy to collect samples of GCF.2. Contents of RANKL/OPG in gingival crevicular fluid in mesial impactedmandibular third molar with non-pericoronitis is lower than that in pericoronitis.But it is higher than non-mandibular third molar, which showed alveolar bone ofadjacent teeth tends to absorb under mesial impacted mandibular third molarwas no inflammation condition.3. Contents of RANKL/OPG in GCF nearby in mesial impacted mandibularthird molar which has pericoronitis is obviously higher than other groups, whichshows that OC acts clearly. Therefore, it is perhaps that mesial impactedmandibular third molar with pericoronitis has an effect on alveolar bone nearby.