i'm not too experienced in this branch of horary, but this is what I see.
You are Saturn.
The dental procedure is the 10th sign/place ruled by dignified Venus, so strong.
Saturn exalts Venus in Libra, so you may have some exaggerated expectation of the outcome. And Saturn is actually in the 12th sign/place which may contribute to your doubt, along with Moon in Scorpio as your co-significator, separating from combustion with the Sun, may point to your unease in anticipation.
But Venus applies without interference to Saturn by sextile. So this looks pretty favorable overall to me: both the procedure itself [robust, tried and true as reflected by Venus dignified in Libra and in the house of the procedure] and the outcome [as indicated by the unimpeded trine between you/Sat and the procedure/Ven].
Moon, as indicator of the question's unfolding, applies to a sextile, albeit to Mars, so it seems that things should go pretty well. Perhaps with Scorpio's influence on Moon, its leaving combustion, and its aspecting Mars, Scorpio's ruler, there may be a bit extra bleeding, but I suspect that this likely is not uncommon in a dental procedure.
Moon is about to change sign very soon, so that may help you feel better in anticipation as well.
I hope experienced medical horary folks will offer their view as well.