Abstract: A tooth-adhesive compound is expressed in terms of the following general formula: ##STR1## wherein R.sub.1 is a hydrogen atom or a methyl group, andR.sub.2 may or may not be present; and if present, R.sub.2 is an alkylene group having 1 to 4 carbon atoms or a --CH.sub.2 --CH.sub.2).sub..eta. O--CH.sub.2 --CH.sub.2 -- group in which n=1 or 2, and a substituent containing R.sub.1 and R.sub.2 is located at the o-, m- or p-position with respect to the carboxyl group bonded to the phenyl group.

Abstract: A compound which is bondable to tooth substrates, and has the following general formula: ##STR1## wherein: R.sub.1 is a substituted naphthyl group having a ##STR2## group at any one of the 1,2-, 2,3- and 1,8- positions, R.sub.2 is any of the following groups having any one of carboxylate, carbonyl, and --O-- moiety, to be connected to R.sub.1 :a group having the formula --(CH.sub.2).sub.m -- in which m=1-4,a group having the formula --(CH.sub.2).sub.n --COO--(CH.sub.2).sub.p -- in which n.noteq.0, p.noteq.0, and n+p=2-4, ora group having the formula --(CH.sub.2 --CH.sub.2 O).sub.q --CH.sub.2 --CH.sub.2 -- in which q=1 or 2,wherein when said R.sub.1 group is substituted at the 1,2 position, then R.sub.2 is bonded to the naphthyl group at any one of the 4, 5, 6 and 7 positions; when said R.sub.1 group is substituted at the 2,3 position, then R.sub.2 is bonded to the naphthyl group at any one of the 5 and 6 positions; and when said R.sub.1 group is substituted at the 1,8 position, then R.sub.