In Vitro Comparison Of Penetrating Resin And Total Etching Adhesive In The Treatment Of Cracked Permanent Teeth

Objective Crack of teeth,also known as cracked teeth syndrome,is a common disease in dentistry.Cracks can be defined as "a line along the surface of a splitting object without splitting".Cracks on teeth may extend from harmless crack line to enamel layer,and the crack plane can extend to the outer surface of teeth(which may be clinical).The crown can also be the root of the tooth or the pulp chamber(with the most severe periapical periodontitis).The causes of cleft teeth include previous repair,occlusal factors,developmental conditions/anatomical considerations,trauma and other factors(such as aging),and may also be due to the wedging effect of maxillary and middle palatal apex on the central cleft valley of mandibular molars.Mandibular molars are most common,followed by maxillary premolars,maxillary molars and mandibular premolars.The early stage of cracking is confined to enamel without symptoms.With the deepening of cracks,discomfort symptoms such as tooth pain will occur.Severe patients often complain of severe pain and/or heat-sensitive irritation pain when biting.However,the perceived symptoms may vary according to the depth and direction of cracks.Therefore,cracks are concealed and difficult to diagnose.It may be of limited diagnostic value to detect cracks by X-ray,because cracks may be parallel to the film plane.It is helpful to use a lamp to make teeth pass through silicon wire.It was agreed that symptomatic history,sensitivity to cold stimulation and positive occlusal tests might indicate the existence of incomplete dental cracks.Even if diagnosed and treated,the efficacy would be difficult to guarantee,and sometimes it would impose a heavy burden on the operator.Therefore,the treatment of this disease requires an economical,predictable and preventable treatment.Treatment means.For incomplete cracks,recognized treatment methods include grinding the sharp cusp,reducing the height of the cusp,reducing leverage,and reducing the angle between the cusps,reducing the lateral jaw.The purpose of sealing the cracks is to fix the selected dental materials on the tissue walls of the teeth on both sides of the crack plane,so as to prevent the independent movement of the broken parts under occlusal load and the independent movement of the parts on both sides of the fracture surface,which is helpful to restore the inherent fracture toughness of the teeth.Treatment of cracked teeth.There is limited evidence for the success rate of total etch binders in the treatment of cracked teeth.There is evidence that the use of adhesives in the treatment of cracked teeth has a short-term effect,with an annual failure rate of 6%.This makes the repair method less popular.The failure may be due to the rupture of the periodic functional load at the attachment interface(between the teeth and the total etching adhesives),thus affecting the long-term effect of the repair.When all-etching adhesives are placed,cusp shrinkage may also occur due topolymerization shrinkage,which may lead to further expansion of cracks.If the cracks in the posterior teeth extend to the dentin,it is reasonable to assume that the fracture toughness of the teeth may be damaged.For this reason,it is necessary to repair cracked teeth as early as possible.With the continuous development of materials,the concept of minimally invasive therapy has continued to emerge,and Icon resin is the most effective new material in minimally invasive therapy.This paper is mainly about the study and comparison of Icon Caries Infiltrant and total acid etching adhesive in the treatment of permanent tooth occult fissure.It is concluded that there is difference in therapeutic effect between Icon Caries Infiltrant and total acid etching adhesive in the treatment of cracked teeth and permanent teeth.Methods 30 healthy third molar were selected.Two hidden cracks were made in the symmetrical part of the labial side by using a laser puncher.The crack line ended at the enamel dentin boundary.The diameter is 0.001 mm and the thickness is 2 mm.The cracks were treated with Icon CariesInfiltrant and acid-etching adhesive respectively.The changes of the cracks before,during and after operation were observed under the naked eye;Along the long axis of the tooth,cut the two symmetrical enamel blocks with a fast cutter.Polishing,make a hidden crack with a fast turbine and a laser puncher.The diameter is 0.001 mm and the thickness is 2 mm.The crack line ends at the inner edge of the glazed tooth.All samples are divided into two parts.One part is treated with Icon Caries Infiltrant,and the other part is treated with a total acid etching adhesive.The average enamelmicrohardness is measured separately.The data of each group is counted.The statistical description is performed by (?)±s.SPSS19.0 software analysis,The test level ?=0.05,with P<0.05 as the difference is statistically significant.Results The average enamel microhardness of the sample treated with Icon Caries Infiltrant was significantly higher than that of the total acid etching adhesive,and there were significant differences between the two groups(P<0.01)The difference is statistically significant.Conclusion Icon Caries Infiltrant is better than total acid etching adhesive in the treatment of cracked tooth.It provides a better treatment for early cracked tooth,but its long-term effect still needs long-term research.