Recent surveys show that the prevalence of edentulism is reducing.1 These data reflect the conditions of developed countries, or small, selected populations.2,3 In fact, edentulism still represents a major concern for patients, clinicians, and for general public health. Because of the advances in dental therapies and the longer life expectancy, there is a delayed transition to fully edentulism. Edentulous patients refer functional problems, such as diminished chewing efficiency, nutritional imbalance, and reduced quality of life (QoL).2,4,5 Before the refinement and acceptance of dental implants, removable dental prostheses had for decades represented the sole method to solve the problems related to complete edentulism

Objective
The purpose of this report is to compare satisfaction of patients rehabilitated with full-mouth fixed prostheses using computeraided flapless implant placement and immediate loading with patients rehabilitated with conventional removable prostheses. Materials and Methods: The study included 30 consecutive fully edentulous patients who received 312 implants and 30 matched controls treated with conventional removable prostheses. Mandible and maxilla were treated in the same surgical session with computer-guided flapless approach using NobelGuide protocol. Prefabricated screw-retained fixed prostheses were inserted at the end of surgery. Clinical and radiographic evaluations were assessed at 6, 12, and 36 months. At baseline and 5 years after prostheses delivery, patients answered OHIP-EDENT questionnaire (Oral Health Impact Profile for Edentulous subjects) to assess satisfaction. Results: The implant survival rate was 97.9%, whereas the average marginal bone loss was 1.9 6 1.3 mm after 3 years. At 6 months, patients showed significantly greater satisfaction with their fixed rehabilitation as compared to conventional dentures.

Conclusions
The results of this study confirm that rehabilitation with a prefabricated fixed prosthesis supported by implants placed with NobelGuide protocol significantly increases the quality of life in fully edentulous patients when compared with complete dentures. (Implant Dent 2017;26:54–58) Key Words: edentulous mouth, immediate dental implant loading, computer-aided surgery, quality of life. However, the use of dentures may induce complications and associated clinical manifestations, such as stomatitis, traumatic ulcers, irritation-induced hyperplasia, altered taste perception, burning mouth syndrome, and gagging. Moreover, wearing a denture enhances the physiological alveolar bone resorption because of tooth loss, compromising the stability of the denture itself. The introduction and development of improved root-form endosseous implants represented a new approach and long-term therapeutic solution for complete edentulism. Many different treatment modalities have been proposed to treat edentulous patients by means of endosseous root-form osteointegrated implants. These treatment modalities can be generally categorized into (a) fixed implant-supported prostheses (FP) and (b) removable implant-supported prostheses (RIP).4,6–8 Clinical studies have demonstrated that prosthetic treatments increase patients’ satisfaction or QoL.6–8 Single-arm studies have showed improvement in oral health-related quality of life (OHRQoL) both in the FP9 and RIP,10 but currently not many data are available on the comparison between OHRQoL in patients receiving FP and complete dentures (CD). The aim of this study was to compare patients’ satisfaction and OHRQoL in fully edentulous patients who received FP or CD.

MATERIALS AND METHODS
Study Design and Subjects This study was designed as a multicenter, retrospective, nonrandomized, controlled study for surgical placement andimmediateloading of dentalimplants. From September 2008 to July 2009, at 4 different study centers, 30 consecutive fully edentulous patients (18 women and 12 men) in both maxillary and mandibular arches were enrolled in the trial and provided written informed consent to participate in the study. At the first visit, an examiner recorded medical history and clinical evaluation. There was no limitation based on medically compromising conditions, such as anticoagulants, beta-blocking agents, hypertension, and hypothyroidism. The exclusion criteria were radiotherapy in the maxillary region, bisphosphonate therapy, remaining teeth that could interfere with implant placement, inability of mouth opening sufficiently to accommodate the necessary surgical instrumentation (at least 50 mm), and lack of available bone volume. For the edentulous maxilla, the anatomical inclusion criteria were a residual alveolar ridge crest measuring at least 4 mm in width buccolingually and 10 mm in vertical height from canine to canine. For the mandible, the anatomical inclusion criteria were an alveolar ridge width at least 4 mm and a vertical height of at least 8 mm. Thirty fully edentulous subjects were selected as matched controls for age, sex, and center, between those who had received complete removable prosthesis during the same period.

All 60 patients were recalled after 1 day, 10 days, 4 and 6 months, and subsequently, annually. Panoramic radiographs were recorded annually for patients belonging to the implant group. The presence of radiolucencies indicative of a fibrous encapsulation and potential failure of the endosseous implants was noted. Periapical radiographs were made at implant insertion and again at 6 and 12 months with a long-cone parallel technique using a conventional radiograph holder (Rinn centrator bite; Dentsply Rinn, Elgin, IL) individualized for each site with an acrylic resin template. Bone level measurements were performed by an independent radiologist at the Division of Neuro-Radiology, University of Florence CTO, Italy; the reference point for the reading was the implant platform (the horizontal interface between the implant shoulder and the abutment), and marginal bone remodeling was defined as the difference in marginal bone level relative to the bone level at the time of surgery. The mean and SD of the marginal bone level were calculated. The patient records were retrospectively analyzed using descriptive statistics. The marginal bone remodeling, the number of implants placed, the number of implants lost (and the causes of loss), their diameters, and survival time were recorded. Implant survival rate analysis at 5 years of follow-up with the Mantel-Cox test of log ranks and a paired t test for assessing differences in marginal bone levels at 60 months were performed. All patients belonging both to implant and nonimplant groups filled in a questionnaire to assess the OHRQoL (Oral Health Impact Profile for Edentulous patients; OHIP-EDENT) at baseline and after 60 months from intervention.

Questionnaire
Patients’ satisfaction was assessed using the OHIP in Edentulous Adults (OHIP-EDENT) questionnaire. The OHIP was developed in Australia by Slade and Spencer in 1994, and the tool comprises 49 questions distributed into 7 subscales. However, some authors considered the questionnaire too farreaching, and a number of studies have explored the possibility of downsizing it, without impairing its scope of application. Among the short versions that have been developed, the authors selected for this study the Italian version of the OHIP-EDENT, which deemed the most appropriate for edentulous patients. The tool detects the impact of oral health on the QoL of patients with total prostheses, before and after they have received them.

RESULTS
In 30 consecutive patients, followed up to a 5-year period, a total of 312 implants were placed in the mandible or the maxilla. The implant lengths varied between 8.5 and 18 mm, and implant diameters were either 3.3 mm (n ¼ 18), 3.75 mm (n ¼ 130), or 4 mm (n ¼ 164). The implant types used for this study included Nobel Speedy Groovy (192) and Brånemark Standard MKIII (130) (Nobel Biocare AB). A total of 135 implants were inserted in the mandible and 177 in the maxilla. The overall implant survival rate at 5 years was (300-) 96.1% ([168-] 94.9% for the maxilla and [132] 97.7% for the mandible). No statistical significant difference was recorded between survival of maxillary and mandibular implants (x2 ¼ 0.768). Three maxillary implants were lost in the first 3 months of healing, 2 after 6 months, 1 after 12 months, 2 after 36 months, and 1 after 48 months of loading. One implant was lost in the mandible, failed after 24 months because of chronic periimplantitis, and 2 were lost after 48 months. The clinical time necessary for implant placement and delivery of 2 provisional prostheses varied from 1.5 to 2.5 hours. All provisional prostheses were delivered the same day after implant insertion. The patients’ postoperative discomfort such as swelling and pain was almost negligible. After 4 to 6 months of osseointegration, patients had the choice of replacing the fixed provisional prosthesis with a definitive metal-acrylic or metal-ceramic complete bridge. Only 3 patients opted to replace the transitional maxillary prosthesis with metal ceramic–fixed denture for aesthetic reasons, whereas there were 6 patients who received a definitive titanium acrylic–fixed denture. After 5 years of follow-up, the definitive and the provisional prostheses were all still in function. Nine patients experienced fracture of the acrylic resin (6 mandibular and 3 maxillary prostheses). Six of these patients were diagnosed as heavy bruxers. This problem was solved by repairingthe prosthesis, adjustingthe occlusion, manufacturing an occlusal night guard, and giving patient further instruction regarding overloading of the prosthesis. Patients in the control group were recalled every year for a prostheses checkup. Questionnaire Our research team used the Italian version of the OHIP-EDENT

Questionnaire
Previous studies have shown that functional aspects, social aspects, and overall satisfaction were important factors in the evaluation of patient satisfaction.11,12 Based on the literature, these aspects were evaluated through a questionnaire to measure patients’ satisfaction after prosthetic treatments. OHIP-14 is one of the most commonly used instruments for measuring OHRQoL. It was derived from the original extended version, OHIP-49, which was developed in 1994.13,14 Although in its short form, it has proven to be reliable and valid in several languages.15–19 The self-reported questionnaire consisted of 14 items divided into 7 dimensionsdfunctional limitation,physical pain, psychological discomfort, physical disability, psychological disability, social disability, and handicap. To make it easier for the patient, a choice of only 3 answers was given: (0) ¼ never; (1) ¼ sometimes; and (2) ¼ usually, unlike the English version of the questionnaire, which gives a choice of 5 answers. The lowest scores represent a satisfactory perception of an individual’s oral conditions, and therefore higher satisfaction and better QoL. One examiner only delivered the surveys at baseline, before surgery, asking subjects to rate their satisfaction with various aspects of their denturesand their functional difficulties. Six months after the surgery, subjects completed further OHIP-14 questionnaires to assess the impact of their prostheses on their OHRQoL. Baseline and 6-month data were collected, and mean and SD were calculated as summary statistics for all variables. Within-group changes were tested using the Fisher exact test: P-values lower than 0.05 were considered statistically significant.

Data Analyses
Statistical analyses were performed using IBM SPSS Statistics v.20 (IBM, Armonk, NY) at a significance level of 0.05. Data were analyzed using descriptive statistics for representing frequencies of subject characteristics. The characteristics of the groups were compared using the chisquare test or Fisher exact test for categorical variables. For patient satisfaction after prosthetic treatments, the median scores were compared using a nonparametric Mann-Whitney test because data were not normally distributed according to the Shapiro-Wilk test. In addition, changes in OHRQoL were calculated as the difference between OHIP-14 median scores before and after treatment. Among the groups, changes in OHIP-14 median scores were compared using the Mann-Whitney test. RESULTS General Characteristic Sixty subjects took part in this study. The general characteristics of the 2 groups are shown in Table 1. Because patients in both groups were matched for age, sex, and center, no significant differences were recorded between groups (P . 0.05).

Change in the OHRQoL Before and After Treatment
As the Shapiro-Wilk test showed that the results of the 2 groups (total OHIP-14 scores) were not normally distributed (P ¼ 0.006), the Wilcoxon signed-rank test was performed to check differences in OHRQoL before and after prosthetic treatments. There were no differences in total OHIP-14 scores before treatments between the 2 groups (MannWhitney test, P ¼ 0.622; Table 2). After prosthetic treatment, limitation in QoL due to oral issues was significantly reduced in all 7 dimensions and in the total OHIP-14 scores for all 2 groups (P , 0.05, Table 2). In other words, OHRQoL was significantly improved after treatment in both groups (FP ¼ 22 and CD ¼ 17), difference of total OHIP14 median scores (Table 3). The level of OHRQoL improvement was higher in all dimensions for the FP group than that for the CD group, while the CD group showed improvement of the OHIP-14 score of 3 as the median difference only in the 2 dimensionsdpsychological disability and social disability. There were significant differences in the degree of improvement of OHRQoL between the 2 groups (P , 0.05), and total OHIP-14 scores improved in the FP (P ¼ 0.061) group compared with the CD group.

DISCUSSION
The results of this study confirm that prosthetic treatments can provide better OHRQoL for fully edentulous patients, and the FP may improve OHRQoL and patient satisfaction better than CD treatment. Analysis of the 7 dimensions of OHIP-14 showed that FP groups had better results compared with the CD group for functional limitation, physical pain, psychological discomfort, and psychological disability. Cost of treatment was also one of the factors that influenced edentulous patients’ preferences for prosthetic treatment.20 The factors considered when deciding on types of prostheses, such as treatment location and costs, may influence OHRQoL as well as clinical outcomes; and an understanding of these factors helps clinicians provide the best treatment that matches patients’ desires.20,21 Comparison of OHRQoL using OHIP-14 scores before and after prosthetic treatments revealed that all 2 groups showed higher QoL after treatment than before treatment. In addition, comparing the degree of improvement on OHRQoL in all dimensions among the groups, the FP showed a greater improvement than the CD group.

The results were consistent with the findings of earlier studies.22–24 The FP group’s QoL that was measured with OHIP-14 increased more significantly compared with the CD group’s QoL.22,24 For the FP group, there were statistically significant improvements on OHRQoL in functional limitation, physical pain, psychological discomfort, and psychological disability (P , 0.05). The advantages and important factors for the choice of FP treatment are comfort and stability caused by a sufficient number of implants being fixed, such as that experienced with natural teeth. However, this may increase financial burden and increase the potential risk of surgery.6,8,11 Meanwhile, although improvements of OHRQoL in the CD group were relatively low, CD is currently the cheapest prosthetic treatments available. Therefore, further research on the OHRQoL and costs considering the number of implants and the detailed prostheses type would be needed. This study had certain limitations. First, the study was performed with 30 FP, and 30 CD patients, resulting in a smaller sample size which limited representation. Then, patients’ preference may influence the outcome, especially when the treatments cannot be blinded and the outcome is based on patients’ evaluations fortreatment.21Therefore, it is necessary to consider the patient preferences for treatments. However, because this study was performed retrospectively, we could not evaluate the effect of patients’ preference on patientsatisfaction and QoL. The 5-year follow-up revealed that each of the definitive and provisional prostheses was still in function. During this period, fracture of the acrylic resin prosthesis occurred in 6 mandibular and 3 maxillary restorations. After an examination of potential etiological factors, it was determined that 6 of these patients were diagnosed as heavy bruxers. Each prosthesis was then evaluated, repaired, followed by proper equilibration of the bite. The patients were then provided with occlusal night guards and specific instructions regarding the potential overloading of the prosthesis.

CONCLUSIONS
Although this study had limitations, a comparison of 2 prosthetic treatment options was completed for fully edentulous patients using OHIP-14 (Oral Health Impact Profile) questionnaire. The results indicated that fixed prostheses might provide greater OHRQoL improvement and patient satisfaction compared with CD. This study confirms that rehabilitation with a prefabricated fixed prosthesis supported by implants placed with NobelGuide protocol significantly increases the QoL in fully edentulous patients when compared with CD.

DISCLOSURE
The authors claim to have no financial interest, either directly or indirectly, in the products or information listed in the article.

APPROVAL
No Ethical Committee number was obtained since, according to the Italian Law, there is no need for a formal approval for this observational study.

References

SUPPORTING OUR EVENT

PLATINUM SPONSOR

GOLD SPONSORS

SPONSORS