I'm sorry, this is 100% false. Modern dental anesthesia residents complete a 3-year hospital-based anesthesia residency. This means they are fully integrated into the medical anesthesia team. DA residents do all the cases in the hospital just like the physician anesthesia residents (except for OB, but that isn't an issue because dental anesthesiologists don't need to know how to do spinals/epidurals...some MDs don't even do OB after they finish residency). DA residents treat ALL patients coming through the hospital OR, ASA 1-6, both outpatients and very sick inpatients; routine lap appys to emergent level 1 traumas in the middle of the night. Everything. If you weren't looking at the resident's ID badge, you wouldn't know if they had a DDS or a MD. Clearly, DA residents are trained "to handle complications."
Now, with that said, I would strongly argue that DA residents are significantly better trained to perform deep sedation and general anesthesia (nasally intubated) on dental/omfs patients in an outpatient setting. Why? Because we do it 100x more in residency that the physician residents. Also, at most programs, DA residents get significantly more pediatric anesthesia training than physician residents. Dental anesthesia residencies are comprehensive, with focus on how to actually treat dental patients (both pediatric and adult) in both inpatient and outpatient settings.