I have had IMTEC implants for three years. The O rings need replacing very often. Sometimes not lasting more than one month. I do not soak my denture in any solution, lightly brush the o-ring site every night after removing the denture when I go to bed. The o-rings are black rubber-type rings. Do they have another type o-ring that will hold up longer? Why would this constant replacement of o rings be happenening? Thanks.