Is it normal for front teeth to occasionally hit on s sounds while speaking?

I got a permanent bonded retainer last month and since then i noticed that occasionally my right top front tooth hits my right bottom front tooth while talking, this is rather a "soft hitting", not a jamming or anything, and happens only on s sounds, not every time but let s say once in a 15 min conversation. Can this be harmful for the involved teeth as the enamel of both teeth are touching? My bottom right tooth was previously turned slightly inward but got straightened now.