Retention of Teeth Versus Extraction and Implant Placement: Treatment Preferences of Dental Faculty and Dental Students

Methods

The proposal and protocol for this survey study were reviewed and approved by the New York University Institutional Review Board and given an exempt status.

One hundred and forty-two full- and part-time practicing general dentist faculty members at New York University College of Dentistry and 321 graduating senior dental students who had lectures in advanced prosthodontics on the diagnosis and treatment planning for implants received letters of invitation explaining the goals and methodology of the study and informed consent to participate in this survey-based investigation. Potential participants were informed that the purpose of this study was to determine their treatment recommendations for specific clinical situations for either retention of teeth by endodontic and restorative treatment or extraction and replacement with dental implants. After informed consent was received, participants were given a treatment planning survey questionnaire (see Appendix). The questionnaire asked the participant’s age, gender, and year of graduation from dental school. The questionnaire consisted of fifteen concise clinical situations for which participants selected one of two treatment choices. The treatment choices for questions 1 through 12 were (A) endodontics and restorative treatment to retain teeth or (B) extraction and implant placement. The survey instructions informed participants that, for questions 1 through 12, selecting treatment option (A) could include periodontal treatment, crown lengthening, posts, cores, and crowns as necessary to retain teeth, while selecting (B) could include any surgical treatment or tissue augmentation procedure necessary for implant placement.

The clinical situations for questions 1 through 12 were arranged based on increasing levels of prosthetic and endodontic case complexities. Questions 1 through 4 (treatment for single teeth), questions 5 through 8 (treatment for multiple teeth), and questions 9 through 12 (treatment for abutment teeth) were categorized for prosthetic treatment complexity. Questions 1, 5, and 9 (direct endodontic treatment), questions 3, 7, and 11 (endodontic treatment through a crown restoration), questions 2, 6, and 10 (endodontic retreatment), and questions 4, 8, and 12 (endodontic surgical treatment) were categorized for endodontic treatment complexity.

Question 13 asked which treatment would be more likely selected for a patient with a compromised medical history: (A) endodontics and restoration or (B) extraction and implant placement. Question 14 asked if the treatment choices would differ for anterior or posterior teeth, with the response options being (A) yes or (B) no. Question 15 asked which treatment recommendation would be selected for replacement of a single missing tooth: either (A) a three-unit fixed bridge or (B) a single-tooth implant.

This survey was a paper and pen document on which participants directly filled in and marked their responses. After the participants independently completed the survey questionnaire, they were anonymously returned. There were no participant identifiers of any kind during the entire survey study process. This survey study was conducted at New York University College of Dentistry for a period of six months from January to June 2005. Data were electronically tabulated and statistically analyzed using the SAS system (Version 9.13, Cary, NC). Comparisons of proportions were performed with Pearson’s chi square statistic or Fisher’s exact test with analysis of trends performed by the Cochran-Armitage trend test.³¹

Results

Of the 142 dental faculty invited to participate in the survey study, 134 independently completed and anonymously returned the questionnaire, a response rate of 95 percent. This participant population sample, of which 76 percent were male and 24 percent were female, had an age range of twenty-six to eighty-two years with mean and median ages of fifty-three and fifty-two years, respectively. The data for the dental faculty participants were stratified into two main groups according to the number of years since graduation from dental school: more recent graduates, in which fifty (37 percent) had twenty years or less since graduation, and less recent graduates in which eighty-four (63 percent) had twenty-one years or more since graduation. Of the 321 senior (fourth-year) dental students invited to participate in the survey study, 253 independently completed and anonymously returned the questionnaire, a response rate of 79 percent. This participant population sample, of which seventy-nine (42 percent) were male and 108 (58 percent) were female, had an age range of twenty-two to forty-two years with mean and median ages of twenty-seven years.

The response percentages for questions 1 to 12 individually and combined for the dental faculty and for the less and more recent graduates of the dental faculty, as well as for the dental students, are presented in Table 1⇓. Among all of the participant groups, there was a higher rate of selection for endodontic and restorative treatment over extraction and implant placement for each individual clinical situation in questions 1–12 and for all clinical situations in questions 1–12 combined. When comparing the treatment preferences for all of the clinical situations in questions 1–12 combined, dental students selected implants more frequently than did dental faculty, and more recent graduates of the dental faculty selected implants more frequently than did less recent graduates. There was a statistically significant difference between the proportions of faculty and students recommending implant treatment (χ²=114.36, df=1, p<0.0001), with students recommending implant treatment more often than faculty. There was also a statistically significant difference between the recommendations of more recent and less recent graduates on the faculty, with more recent graduates recommending implant treatment more often than did less recent graduates (χ²=5.37, df=1, p=0.021). If the groupings of less recent graduates, more recent graduates, and students are used as an indicator of educational exposure to implantology, then there is a statistically significant trend toward a greater recommendation of implants with greater exposure to implantology (Z=−10.67, p<0.0001).

The response percentages for the question based on prosthetic complexity and endodontic complexity for the dental faculty and for the less and more recent graduates, as well as for the dental students, are presented in Tables 2⇓ and 3⇓. There was a higher rate of selection for endodontic and restorative treatment over extraction and implant placement by all the participant groups for each of the prosthetic and endodontic case complexity categories.

For the single tooth prosthetic case complexity categories, students recommended implants more often than did faculty (χ²=21.91, df=1, p<0.0001), and more recent graduates among the faculty recommended implants more often than less recent graduates (χ²=7.43, df=1, p<0.01). For the multiple teeth prosthetic case complexity categories, students also recommend implants more frequently than did faculty members (χ²=21.03, df=1, p<0.0001), while there was no difference between faculty members who graduated more or less recently (χ²=0.68 df=1, p=0.408). For the abutment teeth prosthetic case complexity categories, students recommended implants more often than did faculty (χ²=81.79, df=1, p<0.0001), while again there was no difference between the recommendations of more and less recent graduates among the faculty members (χ²=0.66, df=1, p=0.418). Within the entire faculty group and within the student group, the frequencies for the recommendation of implants increased with the prosthetic case complexity (Z=−3.98, p<0.0001 and Z=−11.15, p<0.0001, respectively) as shown in Table 2⇑.

For the endodontic treatment case complexity categories, there were differences in the proportion of implant recommendations between faculty and students for all complexity groups, with students recommending implants more often than did faculty members: direct access (χ²=23.60, df=1, p<0.0001), through crown (χ²=66.26, df=1, p<0.0001), retreatment (χ²=29.36, df=1, p<0.0001), and surgical (χ²=13.59, df=1, p<0.0005). Comparing more and less recent graduates of the faculty, no difference was found between the proportion of implant recommendations for the direct access group (χ²=1.48, df=1, p=0.225) or the retreatment group (χ²=0.05, df=1, p=0.821); however, there were statistically significant differences between these groups for the through crown cases (χ²=4.96, df=1, p=0.026) and the surgical cases (χ²=3.94, df=1, p=0.047). Within the entire faculty group and within the student group, the proportions of implant recommendations increased with the endodontic case complexity (Z=−8.60, p<0.0001 and Z=−8.76, p<0.0001, respectively), as shown in Table 3⇑.

The response percentages for questions 13, 14, and 15 for the dental faculty overall and for the less and more recent graduates of the faculty and the dental students are presented in Table 4⇓. All of the participant groups selected endodontic treatment more frequently than implants for patients with a compromised medical history, but students selected implants more frequently than did faculty (χ²=6.71, df=1, p<0.01) and more recent faculty graduates selected implants more frequently than did less recent graduates (p<0.01). Dental students indicated that the anterior or posterior position of the tooth would influence their treatment selection more frequently than did dental faculty (χ²=17.38, df=1, p<0.0001). More recent faculty graduates also indicated this would influence their treatment selection more frequently than did less recent graduates (χ²=7.19, df=1, p<0.01). All participant groups selected an implant more frequently for the replacement of a single missing tooth with no difference between the students and faculty (χ²=0.97, df=1, p=0.325) and no difference between the less and more recent graduates of the faculty (χ²=3.06, df=1, p<0.081).

Conclusions

Under the parameters of this survey study conducted at the New York University College of Dentistry, the following conclusions can be proposed:

1. Dental faculty and dental students generally favored endodontic and restorative treatment over extraction and implant placement; however, the selection of extraction and implant placement was progressively greater as the educational exposure to implantology became more recent.

2. The selection of extraction and implant placement increased within each group (less recent faculty graduates, more recent faculty graduates, and dental students) as the complexities of prosthetic and the endodontic cases increased.

3. A compromised medical history and the position of the tooth in the dental arch was a factor that influenced the treatment selection among all participants.

4. An implant over a fixed bridge was the treatment of choice for the replacement of a missing single tooth unit.

5. There was a generational trend among the participants toward the recommendation of implants, especially in complex treatment situations.

6. The implications of these findings for patient care indicate that more implant treatment will be recommended in the future and suggest that careful consideration should be given to treatment options that restore and preserve the natural dentition before recommending implants.

7. The challenge for dental education will be to provide dental students with a comprehensive and balanced educational experience that will enable them to make the most appropriate and beneficial treatment recommendations for their patients.

APPENDIX Treatment Planning Survey Questionnaire