As the average life span increases, people are becoming increasingly interested in quality of life, including dietary life. Dental implants are considered one of the most common and popular treatment options for edentulous patients, and there has been remarkable advancement in the techniques and materials in the field. It is known that dental implants have many advantages such as superior masticatory efficiency and adjacent teeth preservation compared to other prosthetics; however, high cost and long treatment period remain the main limitations of dental implant therapy. The fact that a surgical procedure is required is also problematic. In some cases, more invasive procedures such as maxillary sinus elevation or bone graft are necessary for implantation.

Since patients who spend more money and time for their dental treatment expect satisfactory results and dental services in return, it is important to understand the factors influencing patient satisfaction in order to provide better services in the future1,2.

The objective of this study was to estimate the overall satisfaction level of dental implant patients with implant therapy and to monitor patients during the maintenance period to further evaluate factors influencing patient satisfaction.

This study was approved by the Institutional Review Board at Seoul National University Bundang Hospital (B-1109-136-303). For the study, self-administered questionnaires were mailed to patients who had received dental implant therapy at Seoul National University Bundang Hospital (Seongnam, Korea) from October 2003 to April 2005. The main portion of the questionnaires dealt with the evaluation of satisfaction level with implant therapy. Implant therapy was evaluated independently as implant surgery and implant prostheses. Next, evaluation of satisfaction level during the maintenance period was followed in a functional aspect. The questionnaires also contained evaluations of influencing factors that were categorized as pain-related factors, service-related factors, and complication-related factors.

Respondents rated their level of satisfaction on an 11-point scale where '10' was the most positive and '0' was the least positive response. The midpoint in the scale was '5'. In other words, the scores were " '10'=completely satisfied, '0'=completely dissatisfied, and '5'=neither satisfied nor dissatisfied". For the evaluation of influencing factors, a visual analogue scale (VAS) for pain-related factors and a 5-point scale for service-related factors were utilized. The 5-point scale ranged from 'strongly agree' to 'strongly disagree'. For the evaluation of complication-related factors, respondents were asked to report their experience of complications for implant surgery and implant prostheses, independently.

Surgical complications were grossly categorized as neurologic problems (i.e., paresthesia), bleeding problems, temporomandibular joint (TMJ) problems, postoperative infection, implant failure, and others (comment or description). Prosthetic discomfort included occlusal problems, fitting problems, food impaction, repetitive gingival swelling, habitual cheek or tongue biting, and others.

The differences in satisfaction between the groups were analyzed by independent t-test and Mann-Whitney U test using SPSS ver. 15.0 for Windows (SPSS Inc., Chicago, IL, USA). P-values <0.05 were considered statistically significant.

There have been a number of studies that examined the satisfaction level of implant patients by comparing conditions before and after surgery. Siadat et al.3 performed a study on the satisfaction level in mandibular implant overdenture patients by comparing previous prosthetic forms. Wismeijer et al.4 commented that implant overdenture treatment gave patients social rehabilitation as well as oral rehabilitation. Numerous studies were done with edentulous patients who were treated with implant-supported overdentures or implant fixed full dentures, and patients showed high-satisfaction with both treatments5,6,7,8. The patients who were treated with implant-supported overdentures showed a higher level of satisfaction than those who were treated with conventional full dentures9,10,11. Also, studies on patients who were treated with a single implant prosthesis showed a high level of satisfaction12,13. Another study that compared the satisfaction of patients after implant treatment used the VAS to examine the comfort of chewing and compare masticatory function, pronunciation, aesthetics, and hygienic management between natural teeth and implants. This study also used surveys to compare hygienic management, satisfaction of patients' expectations, and cost between natural teeth and implants. They found that 90% or more of patients were satisfied with masticatory function, with 72% responding that there was no difference in masticatory function between their own teeth and the implants. Additionally, 8% of patients responded that their implants felt safer for chewing, and 92% were satisfied with the implants for pronunciation and 83% with the aesthetics14.

This study was designed to estimate the overall satisfaction level of dental implant patients with implant therapy and maintenance period and to further evaluate factors influencing patient satisfaction in the aspects of pain, service, and complications. In this study, the patients' overall satisfaction level with implant therapy turned out to be high in general (mean score: 8.26). Only 5 (5.4%) patients replied 'dissatisfied', while 71 (76.3%) patients responded 'highly-satisfied'. The functional aspects of the maintenance period were also encouraging in that the mean score ranged from 8.20 to 8.91 and a 'dissatisfied' response was reported by fewer than 8 (8.6%) patients.

Evaluation of factors influencing patient satisfaction was also performed. For pain-related factors, VAS scores for more than 60% of patients during and after implant surgery were reported as 'mild' to 'moderate' grade. Interestingly, 10 (10.8%) patients checked a VAS score of '10' under the local or general anesthesia, possibly due to psychological bias. Overall, there was no impact of either intra-operative or postoperative pain on patient satisfaction (P>0.05). For service-related factors, it was remarkable that 70 (75.3%) patients responded 'negative' to the reasonability of treatment cost. It was difficult to statistically compare the 'negative' group with the 'positive' group, because only two patients responded 'positive'. Although it was a hospital-limited score, 90 (96.8%) patients answered that the dental staff and hospital workers at the Seoul National University Bundang Hospital were kind. This was considered to be a result of periodic education on customer-satisfaction as this is an important factor in the evaluation of service facilities. Forty-seven patients reported a 'negative' opinion on the adequacy of the treatment period, while 44 patients answered 'neither agree nor disagree'. Approximately 50% of the patients believed that the treatment period was too long. Therefore, it is important that patients fully understand the healing process for dental implants at the time of informed consent. For complication-related factors, the experience of complications had a negative impact on patient satisfaction level. Although there was a sample size discrepancy between the groups, the influence of each complication and discomfort was examined. Patients who experienced paresthesia (P=0.049), implant failure (P=0.015), occlusal problems (i.e., chewing difficulty) (P=0.001), and repetitive gingival swelling (P=0.001) showed significantly lower satisfaction levels with implant therapy.

In the evaluation of gender differences in influencing factors, female patients showed a higher VAS score for pain than male patients during and after implant surgery. In addition, male patients expressed more 'negative' opinions regarding treatment cost and treatment period. It is recommended that less aggressive surgery or more intensive pain control should be considered for the management of female patients while cost-effectiveness and shortening of the treatment period should be the primary consideration in the treatment planning stage for male patients.

This study shows that the subjective satisfaction of implant patients was influenced by various factors, especially complication-related factors. It is suggested that the prevention of surgical complications is important in delivering satisfaction to patients undergoing implant therapy. For safer implant procedures, further development of surgical technique and instruments is necessary. Gender differences in the treatment planning stage also could be considered.