Denture Placement Research Articles

Technique for preparation of parallel guiding planes for removable partial dentures

The successful treatment of partially edentulous patients with removable partial dentures (RPDs) depends on many factors, including careful treatment planning and design of the RPD followed by clinical and laboratory techniques. To obtain a single path of placement, increase stability, establish retention, and protect the abutments from displacement, the use of parallel guiding planes has been recommended. Guiding planes are defined as ‘‘vertically parallel surfaces on abutment teeth oriented so as to contribute to the direction of the path of placement and removal of a removable partial denture.’’ It is therefore essential to accurately transfer the parallel guiding planes achieved on the diagnostic casts to the natural teeth. Preparing guiding planes intraorally may be technically demanding. Despite the fact that several different techniques for preparing parallel guiding planes have been suggested, guiding planes prepared intraorally may be divergent, possibly reducing the retention of the RPD. The technique described in this article aids the clinician in preparing parallel guiding planes to satisfy the biomechanical needs of the RPD design. The laboratory and clinical procedures for preparing parallel guiding planes are described.

Evaluation of unstimulated flow rates of whole and palatal saliva in healthy patients wearing complete dentures and in patients with Sjogren's syndrome

Statement of problem The palate and upper lip are the regions of oral mucosa covered with the least amount of saliva. These areas are important for maxillary denture retention and stability. Thus, patients with xerostomia or hyposalivation may have problems with the stability of maxillary complete dentures. Purpose The purpose of this study was to compare the unstimulated whole saliva (UWS) and palatal saliva (PS) flow rates of healthy patients wearing complete dentures and patients with Sjogren's syndrome (SS) and to determine whether xerostomia or hyposalivation has a negative influence on maxillary complete denture stability. A further aim was to determine the influence of new complete dentures on UWS and PS flow rates in healthy individuals. Material and methods Thirty-five complete denture wearers, 24 healthy individuals (controls) and 11 patients who fulfilled the diagnostic criteria for primary Sjogren's syndrome (as proposed by the European Community Study Group) were investigated. All participants were questioned about possible subjective oral complaints (xerostomia or instability of the dentures) through use of a standardized questionnaire. In the first part of the study, UWS and PS flow rates of the healthy subjects (controls) and of the SS patients were measured at the initial visit. The flow rate of UWS (mL/min) was collected by the “spitting” method; saliva was collected into preweighed vessels for 5 minutes while subjects were seated in an upright position. Patients were asked to refrain from smoking, eating, and drinking for 2 hours prior to the test session, to avoid swallowing, and to make as few movements as possible during the procedure. The PS flow rate (μL/min/cm 2) was measured using previously weighed filter paper discs placed bilaterally in the region of the maxillary second molars, 15 mm palatally from the edentulous ridge, for 30 seconds. The measuring vessels and paper discs were weighed before and after each collection. In the second part of the study, new complete dentures were fabricated for healthy patients. Flow rates of UWS and PS were measured 7 days after the insertion to compare data with prefabrication values. Mann-Whitney and Wilcoxon rank sum tests and chi-square test were used to analyze the data (α=.05). Results The UWS flow rates were significantly lower in SS patients compared to healthy controls (0.36 ± 0.33 vs 0.09 ± 0.11 mL/min, P<.05), yet the PS flow rate for both groups was not significantly different. Although every SS patient had xerostomia, and 8 out of 11 had hyposalivation, no patient complained about denture instability. Neither UWS flow rate (0.36 ± 0.33 mL/min and 0.39 ± 0.35 mL/min) nor PS flow rate (1.66 ± 0.99 μL/cm 2/min and 1.86 ± 0.45 μL/cm 2/min) was different from the preinsertion values after 1 week of new denture insertion in healthy patients. Conclusion Palatal mucous saliva may help stabilize the maxillary complete denture in patients with hyposalivation. The results suggest that neither UWS or PS flow rate are influenced by the placement of new dentures in complete denture wearers.

Introducing dental students to clinical patient care: the Complete Denture Prosthodontics Transition Clinic.

Using complete denture treatment as an introduction to clinical patient care for dental students, the purposes of the Complete Denture Prosthodontics Transition Clinic at the University of Colorado School of Dentistry are to reduce the time lapse between the preclinical complete denture prosthodontics course and the first denture patient experience, and to encourage development of student self-confidence and skills. In the 2002 spring semester, faculty at the University of Colorado School of Dentistry initiated the Complete Denture Prosthodontics Transition Clinic for DS-II (second-year) dental students, as an introduction to clinical patient care. Each patient was assigned to a team of two dental students. Three Division of Prosthodontics faculty members staffed each clinic session, providing a student-to-faculty ratio of approximately 6.6:1 and a patient-to-faculty ratio of approximately 3.3:1. All DS-II students in the Class of 2004 delivered their first complete dentures no later than 8 months (average, 184 days) after the last day of the preclinical complete denture prosthodontics course. The time from the diagnostic appointment through the denture placement appointment averaged 39 days for patients treated in this program, compared with an average of 98 days or more for previous classes. The program was successful in achieving the goal of reducing the time lapse between the preclinical complete denture prosthodontics course and the first denture patient experience.

US: ReBase & PolyMineral — plastics masterbatch with slaked lime

This article describes a predictable technique for rectifying an asymmetrical incisal plane after the placement of a maxillary immediate denture. The inability to have a wax trial placement precludes an esthetic evaluation of the maxillary anterior teeth, which may lead to esthetic errors. After correction of the incisal plane, a rebase procedure and a clinical remount follow after appropriate healing time for the patient after extraction.

Denture stomatitis and salivary Candida in Brazilian edentulous patients.

Denture stomatitis (DS) is frequently associated with high levels of Candida in saliva and deficient denture hygiene. In order to analyse the incidence of DS and its pre-disposing factors, we evaluated 77 edentulous patients before and 6 months after the placement of new complete dentures. Denture stomatitis was observed in 50.6 and 18.2% of the patients at the first and second evaluation, respectively. Salivary flow, Candida counts in saliva and Candida species were similar in both evaluations. Denture stomatitis and Candida in saliva were more common in females. Our results showed that denture replacement and denture hygiene improvement were useful for DS resolution, particularly types I and II. However, oral and denture hygiene must be continuous, inasmuch as salivary Candida counts remained high and it is considered an important pre-disposing factor for DS.

Long-Term Results after Guided Bone Regeneration with Resorbable and Microporous Titanium Membranes

Summary From the patient's perspective, use of resorbable membranes has some advantages over treatment with titanium devices. First, there is a clear tendency for less impairment of wound healing caused by membrane appliance. Delayed exposures are never seen, and placement of intermediate dentures causes no complications. There are fewer restrictions in diet and less discomfort of treatment caused by exposure of resorbable membranes than have been observed in the titanium group. Finally, no retrieval of membranes is necessary. A negative aspect that can limit treatment outcome has been the ineffective management of early exposures in resorbable membranes. In such cases, the authors advocate for membrane removal as therapy of choice. In contrast, neither temporary symptoms such as mucosal edema nor the more frequent finding of membrane collapse has too much clinical relevance. From the surgeon's perspective, microperforated titanium membranes might deliver a slightly better performance than resorbable membranes. The authors' histologic data demonstrate increased graft maturity and decreased soft tissue formation within the graft. Bone shield placement clearly requires a more accurate intraoperative adaption to the anatomic situs than does resorbable membranes. Even minor disadaption causes undesired plication of devices. The authors suggest placement of titanium bone shields in the hands of somewhat experienced surgeons. Failed mucosal healing and delayed exposure of titanium membranes have been observed after placement of intermediate dentures. Treatment was effective in most cases by local antiseptic care. Although pain, shortening of follow-up intervals, dietary restrictions, and overall discomfort during treatment have been the consequences for patients. Patients should refrain from permanent placement of intermediate dentures after bone shield placement, if possible. It is fact that guided bone regeneration can be engaged effectively in restorative bone surgery. Resorbable and nonresorbable devices enabled successful placement of dental implants. The authors cannot make a definitive statement whether resorbable or nonresorbable barrier materials meet best therapeutic requirements. The optimal choice of which material to use depends on several factors, such as basic local status, the treatment schedule, the patient's compliance, and the surgeon's experience. The authors still believe that the ideal material for guided bone regeneration has not been found yet. Liquid resorbable barrier materials could be engaged that meet physical requirements needed for proper stress resistance at the grafted site once they harden. Alternative remedies should demonstrate adequate kinetics of degradation and should cut down on complications caused by improper adaption. Further improvements in feasibility reliability, and predictability of reconstructive procedures on behalf of the patient are the task. Further studies are needed to achieve that goal.

Ten-year survival rates of teeth adjacent to treated and untreated posterior bounded edentulous spaces

Statement of problem. Failure to replace a single missing posterior tooth may lead to a variety of dental problems, which may ultimately result in tooth loss. However, little is known about the fate of the adjacent teeth if a missing posterior tooth is not replaced. Purpose. This retrospective study evaluated the survival of teeth adjacent to treated and untreated posterior bounded edentulous spaces. Material and methods. Data were obtained from electronic treatment records from the Kaiser Permanente Dental Care Program, Portland, Ore. A final sample of 317 patients who met the study inclusion criteria was identified. Each bounded edentulous space was placed in 1 of 3 treatment categories: untreated, restored with a fixed partial denture, or restored with a removable partial denture. Subsequent treatment and the status of the teeth adjacent to the bounded edentulous space were followed through December 1999. Ten-year Kaplan-Meier survival estimates were generated for each treatment group, and differences in survival were evaluated with the log-rank chi-square test (α=.05). Results. There was a significant difference in survival among the 3 treatment categories (P=.005). Spaces restored with a fixed partial denture had longer 10-year survival estimates (92%) than those that remained untreated (81%). Spaces restored with a removable partial denture had the poorest 10-year survival rate (56%). Conclusion. Under the conditions and selection bias associated with this retrospective study, the survival of teeth adjacent to a single posterior edentulous space was negatively associated with removable partial denture placement compared with no treatment or the use of a fixed partial denture. (J Prosthet Dent 2001;85:455-60.)

Fabricating a stable record base for completely edentulous patients treated with osseointegrated implants using healing abutments

A stable record base is essential for accurate interocclusal centric relation records in a completely edentulous patient. In implant prosthodontics, several procedures have been suggested for the fabrication of a stable record base. However, these procedures necessitate removal of the healing abutments during the interocclusal record procedure and the trial denture placement, which makes the procedures tedious and time-consuming. When the implant-prosthesis interface is subgingival, the patient may also experience discomfort during these procedures. This article describes a procedure for fabricating a stable record base that uses the healing abutments, which eliminates the necessity of the healing abutment removal and its consequences. Advantages and disadvantages of this procedure are also discussed. (J Prosthet Dent 1999;81:224-7.)

Ischemic osteonecrosis under fixed partial denture pontics: Radiographic and microscopic features in 38 patients with chronic pain

Statement of problem. Previous studies have identified focal areas of alveolar tenderness, elevated mucosal temperature, radiographic abnormality, and increased radioisotope uptake or “hot spots” within the quadrant of pain in most patients with chronic, idiopathic facial pain (phantom pain, atypical facial neuralgia, and atypical facial pain). Purpose. This retrospective investigation radiographically and microscopically evaluated intramedullary bone in a certain subset of patients with histories of endodontics, extraction, and fixed partial denture placement in an area of “idiopathic” pain. Material and methods. Patients from 12 of the United States were identified through tissue samples, histories, and radiographs submitted to a national biopsy service. Imaging tests, coagulation tests, and microscopic features were reviewed. Of 38 consecutive idiopathic facial pain patients, 32 were women. Results. Approximately 90% of subpontic bone demonstrated either ischemic osteonecrosis (68%), chronic osteomyelitis (21%), or a combination (11%). More than 84% of the patients had abnormal radiographic changes in subpontic bone, and 5 of 9 (56%) patients who underwent radioisotope bone scan revealed hot spots in the region. Of the 14 patients who had laboratory testing for coagulation disorders, 71% were positive for thrombophilia, hypofibrinolysis, or both (normal: 2% to 7%). Ten pain-free patients with abnormal subpontic bone on radiographs were also reviewed. Conclusions. Intraosseous ischemia and chronic inflammation were suggested as a pathoetiologic mechanism for at least some patients with atypical facial pain. These conditions were also offered as an explanation for poor healing of extraction sockets and positive radioisotope scans. (J Prosthet Dent 1999;81:148-58.)

Nontraumatic immediate complete denture placement: A clinical report

This clinical report presents a treatment procedure that makes immediate denture placement a more predictable and less stressful procedure. It provides greater control over the prosthodontic aspects of denture delivery by the restorative dentist, and the convenience of performing the placement procedures in a clean, blood-free environment. The delivery of the prosthesis is less traumatic because extractions and/or surgery are deferred. In addition, by the time the remaining roots are extracted, all denture adjustments will have been made and the patient will have accommodated to the prosthesis.

The effect of diet on the bearing mucosa during adjustment to new complete dentures: A pilot study

Purpose. This pilot study investigated the reliability of the conventional prosthodontic wisdom that a modified diet ameliorates soreness during the adjustment to new complete dentures. Tissue ulceration of the bearing mucosa served as the indicator of patient soreness as a function of diet.Material and methods. Fourteen men were randomly assigned to two equal treatment groups. One group consumed a consistency-gradated diet and the other (control) ate as they wished. New complete dentures were fabricated for both groups by the same provider, technician, materials, and method; the study was double-blinded. Tissue ulceration was assessed and totaled for the 10 days after denture placement, constituting a soreness score.Results. Data analysis identified a significant difference in soreness scores between dietary groups ( p < 0.05). Wearing time had a significant inverse relation to soreness ( p < 0.05) in this study. A host of potential explanatory variables of clinical interest failed to relate significantly to the outcome of soreness.Conclusions. The results of this study indicated that a consistency-gradated diet had a significant effect in diminishing tissue ulceration during the immediate postplacement period for this group of men. Potentially, these findings could contribute to enhanced quality of care and to the more efficient allocation of provider-based resources. (J Prosthet Dent 1997;78:479-85.)

リムーバブルパーシャルデンチャーを用いた歯周補綴の1症例

リムーバブルパーシャルデンチャーを用いた歯周補綴の1症例

MINOR PREPROSTHETIC SURGICAL PROCEDURES

Minor preprosthetic surgical procedures used in correcting an existing problem or in preparing the mouth for prostheses must be based on an exact diagnosis and carefully planned and executed to satisfy clearly definable goals. This article emphasizes that philosophy and includes surgical techniques for managing commonly encountered problems as well as those problems associated with placement of immediate dentures. Predictable results with minimal complications can be expected when one adheres to these guidelines.

A multicenter study of overdentures supported by Branemark implants

Nine clinical centers participated in a prospective study of overdentures supported by Brånemark implants in the maxilla or mandible. The study initially comprised 133 patients provided with 117 implants placed in the maxilla and 393 implants placed in the mandible. The preliminary results indicate a success rate in the mandible comparable with the reports on fixed prostheses. Conversely, overdenture treatment in the maxilla seems to be less favorable than previous reports of fixed restorations. The differences between the fixed and the present overdentures in the maxilla were mainly based on differences in patient selection and bone quality. A total of 32 implants was mobile and removed and another 29 implants were lost to follow-up because of patient dropout up to the first annual checkup after denture placement. A higher implant failure rate occurred in the maxilla. Mucosal reactions were also more unfavorable around implants placed in the maxilla.

Clinical implications of resilient denture lining material research. Part II: Gelation and flow properties of tissue conditioners

The clinical effectiveness of tissue conditioners and functional impression materials is influenced by their gelation and flow properties. Laboratory tests were previously conducted that simulated the conditions of clinical use to the extent possible on six commercial intraoral-gelling resilient denture liners. The liners were found to vary significantly in their gelation times and to flow throughout the 7-day study. Their initial flow after mixing was influenced most by the time of loading. While extrapolations to the clinical environment require caution, the results of this study imply that the dentist should (1) adapt clinical techniques to the gelation times of particular materials, (2) reduce the initial flow of some materials by delaying denture placement on the supporting mucosa, and (3) expect the materials to be effective tissue conditioners for at least 7 days.

The Fixed Mandibular Implant: Its Use in Reconstructive Prosthetics

The main advantages of the FMI are immediate denture placement and function, the versatility for denture construction, and the absolutely parallel abutments that make prosthetic adaptation easy. During the submental approach, the oral and maxillofacial surgeon can perform cosmetic surgery of the submental fat pad and chin. There is usually less pain and swelling as compared with the intraoral dental procedure for placing four or five implants. The FMI is an excellent option for the anterior edentulous mandible or deformed mandible when fixed or fixed removable dentures or overdenture is needed. The team approach allows the surgeon and prosthetic dentist to combine their skills in the management of edentulous patients.

有床義歯が床下粘膜に及ぼす影響 特に血管構築について

Microvascular changes of the denture-bearing mucosa on the hard palate of Japanese monkeys (Macaca fuscata) were investigated on microvascular casts utilizing the acryl plastic injection method (Taniguchi, Ohta et al. 1952, 1955) under SEM and ultrastructure of the endothelium of the blood capillary and surrounding tissues under TEM. The results obtained were as follows: 1. SEM findings of microvascular casts were by 10 days after setting the experimental denture capillary loops appeared a simple hair-pin shape. By 30 days the loops changed into a kind of sinusoidal networks. By 60 days the loops of the network began to sort out and to reform into hair-pin shape. 2. Aspects under the light microscope and SEM were essentially similar to those of its serial changes of the capillary loops. 3. Aspects under TEM were fenestrated capillaries have altered to continuous ones after 10 days, and again reformed to the fenestrated capillaries by 60 days. From the above results, it can be said that, although the subepithelial microcirculatory system is temporarily affected by the placement of an experimental denture, it may adapt itself to the mechanical stress of the pressure and so before recovering.

コーヌステレスコープ義歯を用いた歯周疾患患者のメインテナンスとその臨床的評価

In order to assess by periodontal evaluation the changes that might occur with time in the abutment teeth and periodontal tissues when Konus-Telescope dentures are used as that final treatment of periodontal disease, the dentures (15 units) were placed in 13 patients with missing tooth and periodontal disease and findings at the time of denture placement and 30 months after the placement were compared. The number of cases that exhibited significant changes in hygiene level, tissue inflammation and periodontal pocket depth of the abutment teeth after 30 months was very small, while as many as 85.2% of the abutment teeth showed decrease in tooth mobility. Increase in tooth mobility was not detected in any of the cases. In addition, X-ray examination revealed tendencies toward improvement of the periodontal ligament and remission of alveolar bone resorption in many of the cases. These results suggest that Konus-Telescope denture is highly offers protection of the residual periodontal tissues through its secondary splint action.

Follow-up study of periodontal tissues around the abutment teeth in Konus telescope denture

The purpose of this study was to evaluate the periodontal tissues around the 47 abutment teeth in patients with advanced periodontitis for 5 years maintenance periods. The periodontal and prosthetic treatment were carried out and 16 Konus telescope dentures were applied for 11 patients. During 5 years maintenance therapy, periodontal conditions were observed once a year assessing probing depth, attachment level, tooth mobility index, gingival index, marginal alveolar bone height, width of periodontal ligament and loss of lamina dura. The results showed that increase of probing depth in 0.61 mm and attachment loss in 0.78 mm were observed for 5 years. A slight gingival inflammation occurred and tooth mobility increased in some extent. Enlargement of periodontal ligament space and loss of lamina dura in 40% of abutment teeth were observed for 5 years. There were six decayed teeth, six teeth, from which a intracoronal crown was removed, and two extracted teeth in 47 abutment teeth. In conclusion, the periodontal tissues around abutment teeth in Konus telescope denture changed slightly at one year after denture placement, after which, the periodontal tissues were well maintained.

Mandibular reconstruction using AO plates

The AO plate represents an acceptable reconstructive choice for mandibular defects, with an 86.7 percent success rate demonstrated in this series. Because this method utilizes an alloplast which is precisely and quickly applied, virtually all patients requiring mandibular resection can be considered candidates for reconstruction. Adequate vascularized soft tissue coverage is essential to prevent plate extrusion and fistula formation. This is even more important for radiated patients. The pectoralis major myocutaneous flap provides muscle and skin for large anterior defects. Frequently, lateral defects can be closed primarily without using regional flaps. We suggest bone reconstruction to avoid potential plate fracture and to allow placement of functional dentures. Resections in elderly patients and for palliation will result in ideal cosmetic and functional results with the plate alone. If we exclude the four patients reconstructed with calcium hydroxyapatite and the AO plate, the morbidity rate is quite acceptable. With this group excluded, only four fistulas and eight plate exposures occurred. Only four plate removals were required to achieve wound closure. Evaluation of the titanium plate is in progress. It is hoped that better osseous and soft tissue integration will help to decrease wound complications. A large prospective review of postoperative radiotherapy patients using the new titanium plate has been designed to address this issue. The therapeutic choice between the AO plate and free vascularized bone graft reconstruction remains. The decision process is dependent on the technical skills of the surgeon, the treatment plan, the survival characteristics of the tumor, and the physiologic condition of the patient.