| Background More and more parents began to realize the importance of natural primary dentition.But there are still many primary teeth early fall off because of dental caries,trauma and the like.That will result in the emergence of the problem such as oral function,beauty,speech,growth and development of body and mind,especially for permanent teeth and permanent dentition.Keep healthy complete oral tissue is the main goal of the dental pulp treatment.Pulpotomy mainstay treatment in preserving the vitality of primary tooth and prolonging its life till the permanent successor erupts.In 1930,Sweet firstly suggested that formocresol(FC)can be used in pulpotomy.FC had been in clinical use for a long time.Toxic,mutagenic,and carcinogenic effects of formocresol have led the clinicians to use alternative methods and agents that are more tissue compatible than FC.These reasons have led to the introduction of alternatives for formocresol,such as ferric sulfate(FS),calcium hydroxide,mineral trioxide aggregate,electrosurgery and different laser irradiating systems.Although pulpotomy on primary teeth has been discussed for many years,but there are still a lot of controversy At the moment there is no the most appropriate pulpotomy.It is important to continue to study new or more suitable agentia and technology used in pulpotomy.Laser is a kind of newly developed method that has many advantages,especially for the children whose physical and mental are both special.Theerbium,chromium:yttrium scandium gallium garnet(Er,Cr:YSGG)laser is a laser system that has been suggested to be used for cutting hard tissue,soft tissue procedures,hemostasis,and coagulation.It has been used for gingivoplasty,canal preparation,caries removal,cavity preparation,and root canal sealing.But it is still Lack of in-depth and systematic study about Er,Cr:YSGG laser pulpotomy.That will be a big hot spot that how to make batter use of the Er,Cr:YSGG laser pulpotomy.Objective The purpose of this study was to assess histopathologic and radiographic effects of Er,Cr:YSGG laser pulpotomy on primary molars of piglets.Thus it can provide theoretical support for the chronic pulpotomy therapy by Er,Cr:YSGG laser.And there will provide one more choice that more effective,more comfortable way of pulpotomy for childrenMethods 1.Histopathologic effects of Er,Cr:YSGG laser pulpotomy on primary molars of piglets.Nine healthy piglets were selected,weight about 25 kg,unlimited male,age about 6 months.There are108 teeth were prepared for pulpotomy,each tooth was dealed with 6 different methods of pulpotomy.And three of the nine piglets was killed after 7 days and the teeth were extracted,immediately flxed in 4% paraformaldehyde fix solution.The other six piglets were killed respectively at 30 and 60 days and the teeth were extracted and treated as above.To decalcify the blocks,samples were floated in EDTA decalcified solution Later,the blocks were thoroughly rinsed with running water.The specimens were then dehydrated in an ascending series of alcohol rinses.The blocks were then embedded in paraffin.Transverse cross-sections with diameter of 6 μm were then made.The samples were then stained with HE and were viewed under an optical microscope.A group:bur group.B group:FS group.C group: Er,Cr:YSGG laser(1.75W/30Hz)+(1.0W/25Hz).D group: Er,Cr:YSGG laser(2.0W/30Hz)+(1.0W/25Hz).E group: Er,Cr:YSGG laser(2.25W/30Hz)+(1.0W/25Hz).F group: Er,Cr:YSGG laser(2,0W/30Hz)+(0.75W/25Hz)2.Clinical and radiographic effects of Er,Cr:YSGG laser pulpotomy on primary molars of piglets.The mobility and gingiva situation were evaluated for Clinical evaluation.Radiographic evaluation:before pulpotomy,after pulpotomy,at7,30,60 days,all the teeth take x-ray respectively.Radiographic criteria were as follows: 1.There was an absence of external or internal root resorption.2.There was an absence of furcal,periapical radiolucencies,orwidened periodontal ligament spaces.3.No more than one-third physiologic root resorption had occurredResults 1.Histopathologic effects of Er,Cr:YSGG laser pulpotomy on primary molars of piglets.Seven days after pulpotomy,cross-section of the coronal pulp,thicker and extensive necrotic layer is obvious in the normal group and the ferric sulfate group.Severe inflammatory cell infiltration involving the coronal pulp.The subjacent area near the exposure site exhibited dilatation and congestion of blood vessels in most samples.Thirty days after pulpotomy,the samples still had moderate inflammatory cell infiltration.Sixty days after pulpotomy,slight inflammatory cell infiltration involving the coronal pulp.The subjacent area near the exposure site exhibited fibrillation.Dentin bridge was absent in all samples.Seven days after pulpotomy,compare to the other two groups,thinner necrotic layer and slight inflammatory cell infiltration involving the coronal pulp in the Er,Cr:YSGG laser group.The subjacent area near the exposure site exhibiteddilatation and congestion of blood vessels.Thirty days after pulpotomy,it had a few scattered inflammatory cells in the pulp area.The continuity of odontoblastic layer was maintained in some areas.No inflammation and necrotic tissue were found.Dentin bridge was absent in all samples.2.Clinical and radiographic effects of Er,Cr:YSGG laser pulpotomy on primary molars of piglets.Clinical evaluation: there were no signs of fistula or mobility or any abnormal symptoms in all the groups during the observation perion.The teeth in the laser group had a radiographic success rate61.5%,65.4%,61.5%,73.3%.The teeth in the normal group and ferric sulfate group had a radiographic success rate of 66.7%.There were no statistically significant differences between laser and ferric sulfate group with regard to radiographic success rates.Conclusion 1.Within certain energy parameters,pulpotomy treatment with Er,Cr:YSGG laser is safe and effective in primary teeth.2.Pulpotomy treatment with Er,Cr:YSGG laser showed more superiority than the traditional pulpotomy.3.Er,Cr:YSGG laser may be considered as an alternative to ferric sulfate for pulpotomies in primary teeth. |
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