I'm glad he had no ketones! That's really good to hear. If it were me, I would get the Ketosticks anyway in case he does have ketones in the future. They are pretty cheap and available at any pharmacy (usually with the other diabetes stuff.)
Clindamycin, my vet said, is not as "broad spectrum," and I liked that because I hate to take or give antibiotics unnecessarily. I don't like it that you kill off the good bugs as well as the bad. If Clavamox is broader spectrum maybe you want to try Clindamycin first.
There is no way to know if my cat would have responded the the Clindamycin after the dental because I didn't go that route; the Clavamox is supposed to catch almost everything that Clindamycin would and more. So, it doesn't tell us anything that Clavamox worked for Max after the dental. He had a very bad infection in his gums when I gave him the Clindamycin, and I didn't get a dental then. So, I doubt it tell us anything that the Clindamycin had no detectible effect either. There may have been another infection that Max had in addition to the gum infection that the Clavamox killed or it could be that the dental was absolutely necessary to allow the antibiotic to work regardless of which antibiotic we used.
This is a line from Wikipedia: "Clindamycin is used primarily to treat anaerobic infections caused by susceptible anaerobic bacteria, including dental infections,[3] and infections of the respiratory tract, skin and soft tissue infections, and peritonitis.[4".
There is a side-effect of Clindamycin that you need to look out for: This is another line from Wikipedia: "Overgrowth of Clostridium difficile, which is inherently resistant to clindamycin, results in the production of a toxin that causes a range of adverse effects, from diarrhea to colitis and toxic megacolon.[31]". My grandfather had C Diff, and it was very serious. I made sure he got a yogurt almost everyday for the rest of his life. Cats can get C diff, and it can be detected in fecal samples. So if your cat gets diarrhea, you'll want to get his feces tested, and see if another antibiotic that kills C diff can be administered. Fortunately, my cat didn't have any complications.