It took me 20 years between visits, once !
At my appointment, I went into the room and STOOD rather than got into the scary chair. I explained calmly and clearly what my immediate problem was.............I told the Dentist that I was aware that I probably needed 'other' work to be done, and agreed that if he sorted me out 'now' painlessly and completely, having 'listened' closely to what I told him, I would return and he could do whatever else was necessary.............
..................top bloke, agreed; he got me sorted and I haven't looked back since !!