Objective To explore the application effect of tooth preparation in oral rehabilitation. Methods A total of 100 patients who underwent tooth repair in our hospital from January to December 2021 were selected and divided into control group and observation group according to different tooth preparation conditions, with 50 patients in each group. The control group was treated with traditional tooth preparation, and the observation group was treated with porcelain veneer incisal margin unwrapped unwrapped type-Ⅰ tooth preparation. The treatment conditions and oral function scores were compared between the two groups. Results The cure rate of the observation group (68.00%) was higher than that of the control group (52.00%), and the difference was statistically significant (P<0.05). The incidence of complications (2.00%) and recurrence rate (2.00%) in the observation group were lower than those in the control group (16.00%, 14.00%), and the differences were statistically significant (P<0.05). The satisfaction of the observation group (84.00%) was higher than that of the control group (50.00%), and the difference was statistically significant (P<0.05). The scores of language function and chewing function in the observation group were better than those in the control group, and the differences were statistically significant (P<0.05). Conclusion For patients undergoing tooth repair, the application of porcelain veneer incisal margin unwrapped type-Ⅰ tooth preparation can improve the cure rate, improve the patient's language and chewing function, reduce the incidence of adverse reactions and recurrence rate, and have high patient satisfaction.