Implantological and augmentative procedures may be performed by any dentist, though advanced training in implantology is recommended to acquire specialist knowledge. Maxillofacial surgeons as well as oral surgeons receive a well-founded education in the field of implantology within the scope of their training as a specialist surgeon.
For this study, a questionnaire in paper form was prepared and sent to 250 maxillofacial and oral surgeons, exclusively involving resident surgeons in private practice (oral and maxillofacial surgeons) with the authorization to conduct specialist training in oral surgery. The eligibility to train oral surgeons ensured that the respondents were experienced practitioners. In all cases, telephone contact was established before the questionnaire was sent. In the telephone conversation, the questionnaire was explained, and information about the study objective was provided; willingness to participate in the present study was also requested. If contact was not possible even after several attempts, the interviewee received the questionnaire without advance notice. The study was reviewed and approved by the Ethics Committee of the Medical Association of the Saarland (Ref. No.: 133/11).
Structure of the questionnaire
The first part of the questionnaire involved physician and practice-related characteristics. The part of the questionnaire relevant for this study consisted of clinical case vignettes. For each case vignette, the study participant was asked to choose his/her preferred therapy. The original questionnaire is available as supplementary information (S1).
The present publication addresses clinical case vignettes for the treatment of severely atrophic single- or multiple-tooth gaps.
Clinical case vignettes
To survey the indication practices of the interviewees in implantological therapy, the case vignettes consisted of two real cases of gap switching with a narrow alveolar ridge. The case vignettes included medical anamnesis, clinical findings and X-rays (orthopantomograms and cone beam computed tomography (CBCT) excerpts). The X-rays were used for visualization and were selected such that they could be easily judged when printed on paper. The two cases corresponded to a frequent clinical indication in routine implant therapy.
Both of the two case vignettes had two variable descriptors in the medical anamnesis. The first case vignette dealt with "patient age" and the co-morbidity "endocarditis prophylaxis"; the second addressed the co-morbidity "bisphosphonate therapy" and "surgery anxiety" of the patient. In each of the vignettes, the descriptors had one of two characteristics. Thus, a low or high patient age, endocarditis prophylaxis necessary or not, bisphosphonate therapy present or not and fear of surgery present or not were given; four combinations were possible for each vignette. A random generator was used to achieve an independent distribution of all vignette characteristics in the vignette sets, and this planned variance of individual determinants enables the identification of decision patterns for the preference of a particular therapy. This was intended to reveal whether the therapy decision is different in younger and older patients, in the case of necessary endocarditis prophylaxis or in the presence of bisphosphonate therapy and patients without co-morbidity and in anxious patients and those without fear of surgery. In addition, the influence of the specialist designation on the decision was assessed. The previously mentioned techniques for therapy of the narrow alveolar ridge, bone split, bone block, augmentation with bone substitute material and bone resection were given as potential choices. These techniques covered the three methods for achieving a wide implant site. A therapy could be generally approved or rejected.
To assess the case vignettes for practicability (comprehensibility, consistency of content of the findings and measures), they were tested beforehand by a total of five surgeons for comprehensibility and clinical relevance.
Description of the clinical case vignettes
Case vignette 1 ("single-tooth gap"):
This clinical case vignette established the influence of age and need for endocarditis prophylaxis on clinical decision making.
It concerned a patient in whom tooth 36 had been missing for one year. The patient was a non-smoker and was very critical of the procedure. The X-ray findings (orthopantomogram and CBCT, (Figures 1 and 2)) showed an atrophic alveolar region 36 with sufficient bone height. The referring physician's wish was a single-tooth restoration with an implant to replace tooth 36.
The following variants were built into the vignettes:
Combination 1: Age of the patient 52 years, no systemic diseases
Combination 2: Age of the patient 52 years, endocarditis prophylaxis required because of an artificial heart valve
Combination 3: Age of the patient 76 years, no systemic diseases
Combination 4: Age of the patient 76 years, endocarditis prophylaxis required because of an artificial heart valve
Case vignette 2 ("multiple-teeth gap", three teeth missing):
This clinical case vignette examined the influence of the presence of bisphosphonate therapy (Fosamax) and the patient's attitude towards the intended treatment. The female patient was 57 years old. Tooth 35 could not be preserved due to a longitudinal fracture and had to be removed. The patient could not cope with the provisional prosthesis in region 35-37. Radiographs (orthopantomogram and CBCT, Figures 3 and 4) showed sufficient bone height in region 35-37. The alveolar ridge was atrophied. The referring dentist proposed fixed restoration in the lower jaw.
The following variants were built into the vignettes:
Combination 1:No systemic diseases, the patient was positive about the procedure
Combination 2:No systemic diseases, the patient was very anxious
Combination 3:Fosamax medication, the patient was positive about the procedure
Combination 4:Fosamax medication, the patient was very anxious
For both vignettes, the study participants were asked to choose their preferred surgical procedure. For this purpose, the five aforementioned response options were given: bone split, bone block, augmentation with bone substitute material, bone resection and no therapy.
It was possible to select "yes", "not at all", or "possibly" for the respective therapy options. In this case, "yes" denoted "this option represents the therapy of my choice", "by no means" denoted "this therapy is ruled out", and "possibly" denoted "I am considering this option; I will decide intraoperatively". In addition, the respondents had the opportunity to write down free answers in the section "other".
The data from the questionnaires were collected using Microsoft Excel and analysed using IBM SPSS Statistics 21 (IBM SPSS Statistics, IBM, Armonk, New York, United States) in Windows XP. Microsoft PowerPoint was used to create graphs.
The analysis was performed with complete data sets. Missing information from the participants was excluded on a case-by-case basis. Logistic regressions for binary dependent variables were applied. Assessment of whether the respondent's specialty is related to the preferred care was performed. A probability of error of p<0.05 was interpreted as significant. The raw data are available as a supplementary file (S2).