Implant-retained Dentures Research Articles

Dental Implants

Dental implants are becoming a common practice in the field of dentistry. There has been extensive research in this field, and efforts are being made to improve quality while minimizing costs. A comprehensive study was conducted on diverse dental implants, their design procedures, manufacturing methods using additive manufacturing, and materials as well as future developments. The following types of dental implants were discussed: Single Tooth Dental Implant, Implant-Supported Bridge, Implant-Retained Denture. For the design and force analysis, Mastication and occlusion processes were the focus of the study. The materials that are used for manufacturing these implants were also discussed. Since additive manufacturing is currently a leading manufacturing technology, various methods of manufacturing these implants using additive manufacturing have been studied and discussed. Furthermore, future research and development efforts within the dental implant industry were discussed.

Immediate loading of dental implants in edentulous mandibles using Locator attachments or Dolder bars: A 9-year prospective randomized clinical study.

To evaluate the long-term survival, incidence of prosthetic/technical and biological complications and the oral-health-related quality of life in patients with an edentulous mandible who were fitted with overdentures on two immediately loaded implants in the symphyseal area. Forty-six patients with edentulous mandibles received two immediately loaded implant-retained dentures with either two Locator attachments or egg-shaped bar attachments. Implant outcomes were recorded after a period of observation of 9 years and included prosthetic complications, modified gingiva index (mGI), modified plaque index (mPI), oral health impact profile (OHIP-G) and radiographic estimation of bone loss. In 2020/2021, 27 patients with 54 implants were still available for follow-up. In total, nine implants in six patients were lost. Survival was 89.1% in the bar group and 91.3% in the Locator group. Implant success was 84.6% in the Locator group and 76.9% in the bar group. The mPI values were significantly higher in the bar group than in the Locator group, whereas no difference was seen in the mGI values. During the observation period, 152 prosthetic complications occurred, but the OHIP-G score did not differ significantly. There was no difference in implant survival between Locator or joint bar attachments over a 9-year observation period. Joint bar attachments were associated with slightly more complications, while patients in the Locator group were able to maintain better oral hygiene. The study was registered in the German Register of Clinical (Trials DRKS00004245).

Dental implants: A review of types, design analysis, materials, additive manufacturing methods, and future scope

Dental implants are becoming a common practice in the field of dentistry. There has beenextensive research in this field, and efforts are being made to improve quality while minimizingcosts. A comprehensive study was conducted on diverse dental implants, their designprocedures, manufacturing methods using additive manufacturing, and materials as well asfuture developments. The following types of dental implants were discussed: Single ToothDental Implant, Implant-Supported Bridge, Implant-Retained Denture. For the design and force analysis, Mastication and occlusion processes were the focus of the study. The materials thatare used for manufacturing these implants were also discussed. Since additive manufacturingis currently a leading manufacturing technology, various methods of manufacturing theseimplants using additive manufacturing have been studied and discussed. Furthermore, future research and development efforts within the dental implant industry were discussed.

Immediate implant placement in edentulous oral cancer patients: a long-term retrospective analysis of 207 patients

Although the functional benefits of implants in the rehabilitation of edentulous cancer patients are well-known, most studies report on postponed implant placement. The outcome of immediate implant placement regarding successful rehabilitation, implant loading and survival is unclear. Two hundred and seven edentulous oral cancer patients that received implants during ablative surgery at the Radboud University Medical Centre between 2000 and 2011 were included. Data regarding the oncological treatment, implant placement, follow-up and prosthodontic rehabilitation were recorded retrospectively with a follow-up period of 5–17 years. Functioning implant-retained dentures were made in 73.9% of the patients. Of the surviving patients, 81.9% had functioning dentures after 2 years and 86.3% after 10 years. Patients with ASA score 1 and younger patients were rehabilitated more frequently. The median time of functioning denture placement was 336 days after surgery, with a negative influence of postoperative radiotherapy. Implant survival was 90.7%, and was lower when the implant was placed in a jaw involved in the tumour. Immediate implant placement during oral cancer surgery led to a high number of edentulous patients rehabilitated with implant-retained dentures, which are placed at an early time.

Full-Mouth Rehabilitation With Implant-Prosthesis in Marfan Syndrome Patient: Clinical Report and Literature Review

The purpose of this case report is to present implant-retained maxillary and mandibular complete overdentures in a patient with Marfan syndrome. The patient initially presented with generalized periodontitis (stage IV, grade C). Due to the progressive nature of periodontal disease, the patient elected to have implant-retained maxillary and mandibular complete dentures. Bilateral maxillary sinus augmentation was performed 6 months before full-mouth extraction, alveoloplasty, and immediate implant placement. Maxillary and mandibular immediate overdentures were delivered. After 4 months of healing, the final overdenture was fabricated. The patient was seen regularly throughout the healing process for peri-implant maintenance. Soft-tissue grafts were completed to increase the thickness of the mucosa around the implants. The patient has been followed for 2 years and is functioning well without major complications. For patients with Marfan syndrome, implant-retained prostheses are a viable treatment option in the presence of a failing dentition.

Outcomes of dental and craniofacial osseointegrated implantation in head and neck cancer patients.

Treatment of head and neck cancer may result in disfiguring and debilitating anatomical changes. Osseointegrated implants may be used in these patients to facilitate attachment of implant-retained dentures or cosmetic prostheses. A retrospective audit was performed, reviewing the treatment of patients who received dental or craniofacial osseointegrated implants during treatment of head and neck cancer. One hundred sixty implants were inserted in 54 patients with oral, nasal, orbital, or auricular defects. Overall, 85% of implants were successful after mean follow-up of 25.7 months. The brand of implant used was shown to impart a statistically significant implant survival difference, and orbital implants had poorer survival compared to nonorbital implants. There was a statistical insignificant implant survival advantage in both nonsmokers and patients who did not undergo radiotherapy. Dental and craniofacial osseointegrated implants may be reliably used in patients with head and neck cancer. However, further research is required to clarify the role of smoking in osseointegrated implant failure.

What Is the Monetary Value of Dental Implant Treatments?

The answer to this question may be more than what we think. Naturally, all treatment costs must be reasonable and within the financial reach of the patients we treat in our private practices. What we actually charge for our services needs to be based upon overhead expense, degree of difficulty, our expertise, and what we feel our time, education, judgment, and personal financial needs require. However, once the case is completed and the patient has the pleasure of using the “nice new teeth,” what do patients really think these teeth are worth? How much money would it take for the patient to “sell” these “nice, new teeth”?Several studies have examined the patient's improved quality of life (QOL) when treated with implant-retained dentures.1,2 The majority of studies evaluate QOL by descriptive methods or health evaluations.3 Oh et al,4 found that implant supported over-dentures provided a significant improvement of oral health-related QOL. Implant-retained denture patients had significantly fewer functional limitations, less physical pain, less psychological discomfort, and less disability.4In 2012, Papadaki et al5 found that social behavior and self-confidence were both diminished for many patients wearing complete dentures. Conventional dentures are not an acceptable solution for some patients. The good news is that an implant-retained mandibular denture provides elderly patients with improvements in both oral health QOL and general health-related QOL.6A 2009 Canadian study measured the preferences of edentulous elderly patients regarding mandibular implant-retained dentures using willingness-to-pay (WTP) and willingness-to-accept (WTA) criteria. These researchers also assessed the effect of long-term financing on WTP.7 Seventy percent of the patients were willing to pay three times more than the current cost of conventional dentures for an implant-retained prosthesis. If patients could pay for the implant-retained denture treatment with monthly installments, the acceptance rate was 96%.Sendi et al8 surveyed patients in Switzerland who had received 2 dental implants for the purpose of retaining their mandibular denture. These authors assessed the patient's QOL with the implant-retained restoration based upon their WTP for the implant treatment and their WTA money in exchange for the reversal of the implant treatment. This study revealed that 16 patients (average age 73.5; range 58–87 years) rated their satisfaction with their previous unretained conventional denture with a score of 3.25 (1 = not satisfied at all; 10 = very satisfied). These same patients were then provided with a 2 implant-retained denture. These patients rated their 24-month posttreatment satisfaction score at 9.68. They also found that 11 of 16 patients would not “sell” their implants for any amount of money. Of the 5 patients willing to trade their implants for money, the asking price was anywhere from 2 to 66 times what they paid for them.8Recently, I asked a patient of ours who had received an “all-on-6” implant fixed mandibular prosthesis “How much money would you need for me to take the teeth and implants back?” Her reply was “No one has enough money for me to give these teeth back.” Another patient who had also received an implant-fixed mandibular full arch prosthesis was asked the same question. He answered “These teeth are so good you should have charged me twice what you did.” I think that clearly states the value of what we do for our patients.Yes, we do provide patients with benefits greater than just the monetary number!

Experimental Study of the Biomechanics of Maxillary Implants under Conditions of Biomechanical Modeling.

We studied the stress-strain state of the bone tissue and maxillary full-arch fixed implantretained denture. Load was applied to the anterior (150 N) and posterior (250 N) parts of the denture supported by 6 or 4 implants, including zygomatic ones and placed by on-all-4 treatment technology. The obtained stress values in the bone tissue, implants, and denture show a large strength margin of structural materials. At the same time, the bone strength values were low, especially around the zygomatic and distal implants of all-on-4-implants-supported dentures when the posterior part of the denture was under load.

Oral Health-Related Outcomes in Edentulous Patients Treated With Mandibular Implant-Retained Dentures Versus Complete Dentures: Systematic Review With Meta-Analyses.

The objective of this systematic review was to determine the effect on oral health-related outcomes from mandibular implant-retained dentures opposing maxillary complete dentures in edentulous middle-age and older adults, compared with complete removable dentures in both arches. Randomized controlled trials included participants with an average age of 65 years or older. The Cochrane Library, MEDLINE, and Web of Science were searched. A total of 228 abstracts were reviewed for inclusion criteria, with 14 trials included and analyzed for risk of bias. Eleven of these studies were assessed as being at an unclear risk of bias, and 3 were at high risk. Mandibular implant-retained overdenture therapy showed statistically significant improvements in the patients' general satisfaction ( P = .003), oral health-related quality of life ( P < .001), and chewing ability ( P < .001), over the patients with complete dentures. There were no significant differences in the percentage of patients who were satisfied with their overdentures vs complete dentures for comfort, retention, esthetics, or chewing ability; however, only 2 studies reported these outcomes. In terms of nutritional status 1 year after treatment, vitamin B12 blood levels increased significantly in the implant-retained group ( P = .003), but not the other nutritional values. Implant-retained mandibular overdentures are an option for middle-aged and elderly edentulous patients as they significantly improve some of the outcomes; however, the quality of the evidence was moderate/low, due to the small number of studies included and the risk of bias. Future research should include objective outcomes such as masticatory performance, chewing efficacy, and muscular coordination.

The use of a customized mounting guide for Implant-Prosthetic Restoration of the Fully Edentulous Arch

Reconstruction of fully edentulous arches with implant-retained dentures requires thorough planning and precise registration of the interocclusal relationship, to achieve a successful treatment outcome.

Costs and clinical outcomes of implant placement during ablative surgery and postponed implant placement in curative oral oncology: a five-year retrospective cohort study.

The aim of this study was to compare costs and clinical outcomes of two protocols for implant placement in edentulous oral cancer patients: implant placement during ablative surgery and postponed implant placement. All edentulous patients who underwent curative tumor surgery between 2007 and 2009 at the Radboud university medical center (Radboudumc) and UMC Utrecht, both in the Netherlands, were included retrospectively. At the Radboudumc, 79 of 98 patients received implants during ablative surgery. At the UMC Utrecht, 18 of 95 patients received implants after a disease-free period of at least 6months, because satisfying conventional dentures could not be made. Costs, implant details and clinical outcomes were recorded retrospectively up to 5years after tumor surgery. Individual costs of implant placement were lower in the during-ablative-surgery protocol (€2235 vs. €4152), while implant failure and loading were comparable to the postponed-placement protocol. In the during-ablative-surgery protocol, more patients received implant-retained overdentures (62% vs. 17%) and more patients had functioning dentures (65% vs. 47%), which were placed at an earlier stage (291 vs. 389days after surgery). Overall costs of the during-ablative-surgery protocol were higher, as more patients received implants and functioning implant-retained dentures, which were more expensive than conventional dentures. Placing implants during ablative surgery lowered the individual costs of implant placement and led to more patients with functioning dentures, while implant failure and loading were comparable to postponed placement.

Rehabilitation with implant-retained removable dentures and its effects on perioral aesthetics: a prospective cohort study.

BackgroundThe onset of perioral wrinkles often prompts patients to request treatment. This aesthetic deterioration linked to aging may be associated with tooth and alveolar bone loss in fully edentulous patients.PurposeTo evaluate perioral wrinkles before and after maxillary and mandibular rehabilitation with implant-retained dentures in fully edentulous patients.MethodsIn this prospective cohort, single-center, blinded study, patients requiring maxillary and mandibular rehabilitation with implant-retained dentures were enrolled. The patients were photographed in the same position before and after oral rehabilitation. Wrinkles were evaluated in the photographs by blinded observers using validated rating scales. The following parameters were analyzed: upper and lower radial lip lines, marionette lines, upper and lower lip fullness, nasolabial folds, corner of the mouth lines, and the labiomental crease. Statistical analysis was performed using the Wilcoxon signed ranks test for paired data, with P<0.05 considered significant.ResultsUpper and lower implant-retained dentures were applied in 31 patients (15 males; mean ± standard deviation age 62.13±8.69 years, range 47–77 years). The oral rehabilitation procedures significantly improved (P<0.05) the upper and lower radial lip lines, marionette lines, upper and lower lip fullness, the nasolabial folds, and the corner of the mouth lines.ConclusionMaxillary and mandibular rehabilitation with implant-retained dentures in fully edentulous patients improves perioral aesthetics. Patients requiring oral rehabilitation and desiring perioral aesthetic improvement could benefit from treatment with this type of prosthesis.

Fatigue resistance of denture teeth

AimsThere is no standard test to determine the fatigue resistance of denture teeth. With the increasing number of patients with implant-retained dentures the mechanical strength of the denture teeth requires more attention and valid laboratory test set-ups. The purpose of the present study was to determine the fatigue resistance of various denture teeth using a dynamic load testing machine. MethodsFour denture teeth were used: Bonartic II (Candulor), Physiodens (Vita), SR Phonares II (Ivoclar Vivadent) and Trubyte (Dentsply). For dynamic load testing, first upper molars with a similar shape and cusp inclination were selected. The molar teeth were embedded in cylindrical steel molds with denture base material (ProBase, Ivoclar Vivadent). Dynamic fatigue loading was carried out on the mesio-buccal cusp at a 45° angle using dynamic testing machines and 2,000,000 cycles at 2Hz in water (37°C). Three specimens per group and load were submitted to decreasing load levels (at least 4) until all the three specimens no longer showed any failures. All the specimens were evaluated under a stereo microscope (20× magnification). The number of cycles reached before observing a failure, and its dependence on the load and on the material, has been modeled using a parametric survival regression model with a lognormal distribution. This allowed to estimate the fatigue resistance for a given material as the maximal load for which one would observe less than 1% failure after 2,000,000 cycles. ResultsThe failure pattern was similar for all denture teeth, showing a large chipping of the loaded mesio-buccal cusp. In our regression model, there were statistically significant differences among the different materials, with SR Phonares II and Bonartic II showing a higher resistance than Physiodens and Trubyte, the fatigue resistance being estimated at around 110N for the former two, and at about 60N for the latter two materials. ConclusionThe fatigue resistance may be a useful parameter to assess and to compare the clinical risk of chipping and fracture of denture tooth materials.

A Technique for Removing Implant-Retained Denture: Direct Relining Complication.

The aim of this case report is to present a technique for removing the denture which locked to ball-attachment because of excessive hard relining resin material flows around the ball-attachment. An alternative method was used in the present case. A cylindrical resin was removed with a diamond bur at the level of matrix and by this way the matrix was removed safely. The advantage of the presented method is that it may be extended to other clinical situations when facing a similar complication for implant supported dentures and also that the technique is simple and does not require special equipment.

A comparison of masticatory efficiency in conventional dentures, implant retained or supported overdentures and implant supported fixed prostheses: A literature review

Patients wearing conventional removable dentures often complain particularly about the instability of the mandibular denture. Due to instability of mandibular dentures, there is an increase in the severity of mandibular atrophy. Furthermore, denture instability leads to a feeling of insecurity, inefficient mastication, and overall dissatisfaction with the prosthesis. Placement of endosseous dental implants to retain and support mandibular overdentures or fixed complete dentures have been developed and studied as a method for solving the problem of instability associated with conventional dentures. Implant-retained dentures have many advantages compared to conventional removable dentures. Occasionally, anatomical or financial limitations may prohibit the patient to use of a fixed implant-retained prosthesis. In these cases, a removable implant-retained denture with a limited number of implants may be the possible choice. The aim of this article is to review the literature to compare implant-retained or supported dentures versus conventional dentures in terms of masticatory efficiency, stability, and patient satisfaction.

Comparison of Quality of Life Between Iranians Using Two Implant-Retained Overdenture Prosthesis and Conventional Complete Denture

Background: Clinicians and policymakers are recognizing the importance of measuring health-related quality of life (HRQL) to inform patient management and policy decisions. Objectives: With regard to relation between cultural differences and quality of life (QoL), in this study the QoL of Iranian patients with conventional complete denture and implant-retained overdenture prosthesis according to the increasing penchant of use of implant-retained overdenture prosthesis and lack of studies in this field in our country, has been compared. Patients and Methods: In this cross-sectional study, cluster sampling was conducted in two stages and 90 edentulous patients (45 patients with conventional complete dentures for two jaws (CD group) and 45 patients with a conventional maxillary complete dentures and implant-retained mandibular denture based on two intercanine implants (IOD group)) with the age of above 35 years were selected according to our inclusion criteria. After obtaining permission from the patients, who had been treated at the selected healthcare and medical treatment centers of Tehran, basic information was obtained by a checklist, including gender, age, educational status and housing status; and QoL was measured by a questionnaire of oral health impact profile (OHIP-20). Results: In the group of IOD, 55.6% of the patients had "good" QoL vs. 46.7% of the patients in CD group. Three patients (6.6%) in both groups had "poor" QoL. No significant relationship was observed between demographic factors and different dimensions of QoL, except the average of "psychological disability" in the patients of CD group, which was higher in women. Conclusions: According to this study results, implant-retained overdenture prosthesis provided better QoL for Iranian patients.

OP014: Prosthetic rehabilitation in oncologic patients treated with microvascular free fibula flap for mandibular reconstruction: A series of 24 patients

Purpose Mandibular reconstruction with microvascular free fibula flap (MFFF) is widely used after oncologic resection as it allows functional and aesthetical restoration of the mandibular arch and implant-retained prostheses. The aim of the series is to propose a decisional tree diagram to choose the type of prosthesis through clinical experience and review of the literature. Material and method Patients treated with MFFF and prosthetically rehabilitated were included. Number of osteotomies, number of implants, type of prosthesis, follow up after the placement of prosthesis, pre-implant surgery and peri-implant complications were reported. Subjective criteria such as patient’s satisfaction and improvement of masticatory function were collected. Results Twenty-four patients were included. Number of osteotomies ranges from 0 (9 patients) to 2 (2 patients). Four patients underwent preimplantation surgery on soft tissues and 3 on bone. Seventy-four implants were placed, 4 remained unloaded, and 1 was lost before loading. Ten patients had implant-supported dentures and 14 had fixed prostheses. Prosthetic follow-up was over 5 years for 15 patients and under 1 year for 1 patient. Peri-implant complication was hyperplasia for 7 patients. Patients’ satisfaction was good and masticatory improvement was moderate. Discussion Prosthetic rehabilitation on MFFF evolutes to fixed prosthesis. Nonetheless, it is more complicated to realize, and requires a sufficient number of implants. Peri-implant complications such as hyperplasia seem to occur more often. Implant-retained dentures seem preferable in case of important aesthetical alteration, although fixed hybrid “Branemark like” prosthesis remain a good alternative. Improvement of mastication is more important in patients with large rehabilitations but remain quite disappointing. Finally, one should wonder whether dental restoration is necessary in case of small lateral flaps.

One Versus Two Implant-Retained Dentures: Comparing Biomechanics Under Oblique Mastication Forces

The results from clinical tests of single implant-retained dentures (SIDs) are quite promising. However, the biomechanics of SIDs are still insufficiently determined. The aim of the study was to compare the implant loads and pressures beneath one and two implant-retained dentures (TIDs) under oblique mastication forces. The finite element method was used to conduct a model analysis in order to compare loading of the denture attachment onto the implant that accompanies oblique mastication forces in the cases of SIDs and TIDs. The possibility of a denture detaching and sliding on the mucous membrane surface was simulated. The SID solution faced a more remarkable tilt in the direction of the mastication forces, a higher pressures on the mucous membrane surface, and higher implant loadings. The hingelike restraints in the TID favored utilization of the support in the posterior area. The higher pressure values for the SID can be confusing and could lead to inaccurate conclusions about the acceptability of the SID. In the TID, the same areas of the mucous membrane were persistently loaded, independent of the occlusal force direction. In contrast, in the SID the full freedom of rotational movement enhances alternating use of the mucous membrane. This finding explains the more frequent sores in the mucous membrane beneath the TID than beneath the SID.

Residual ridge resorption, lower denture stability and subjective complaints among edentulous individuals

Residual ridge resorption in the mandible after tooth loss may lead to worsening of complete denture stability and to various subjective complaints. The aim was to evaluate the association between radiologically assessed residual ridge resorption in the mandible, clinically assessed stability of lower complete denture and subjective complaints among elderly denture wearers. The study population consisted of 326 (115 men and 211 women) edentulous subjects aged 60-78years, all of whom were wearing complete dentures in the mandible. Data on subjective complaints were obtained from questionnaires and interviews. Denture stability was assessed clinically. Residual ridge resorption was analysed from panoramic radiographs. The results showed that women were significantly more often satisfied with their lower dentures and reported fewer problems with eating than men. They also had significantly more often residual ridge resorption than men. Among women, residual ridge resorption was significantly associated with poor chewing ability, low satisfaction with dentures and poor denture stability. Among men, residual ridge resorption did not associate with subjective complaints or denture stability. Poor satisfaction with dentures associated significantly with poor denture stability in both genders. In conclusion, these results highlight the importance of denture maintenance treatment. As the extent of residual ridge resorption in the mandible was the most important factor that increased dissatisfaction with lower complete dentures, it is also important to inhibit the progression of resorption by preventing tooth loss or by using implant-retained dentures.

Photoelastic analysis to compare implant-retained and conventional obturator dentures

The use of photoelastic analysis contributes to the rehabilitation of patients with oral-sinus-nasal sequelae, which in turn affect important functions such as chewing, swallowing, and speech. The prosthetic rehabilitation with implant-retained dentures is a suitable treatment option. The purpose of this study was to verify, by using a photoelastic analysis, the stress distribution in implant-retained palatal obturator dentures (relined or not) associated with different attachment systems (O-ring, bar-clip, and bar-clip associated with distally placed O-rings). Two photoelastic models were obtained from an experimental maxillary cast presenting an oral-nasal communication. One model had two 13-mm length implants placed on the left region. A total of eight colorless maxillary obturators were fabricated and subsequently four of them were relined with soft silicone soft, and three had attachment systems associated. The assembly (model/attachment system/prosthesis) was positioned in a circular polariscope and a 100-N load was applied at 10 mm/s. The results showed that the denture relining influenced the distribution and amount of stress on the models. The O-ring group displayed the lowest stress levels, followed by bar-clip system associated with distally placed O-rings and bar-clip groups.