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A procedure to reinforce mandibular complete dentures with a rigid internal horseshoe-shaped frame is described. Sequential clinical and laboratory procedures to incorporate a metal frame at a predetermined, controlled position within the prosthesis are presented. This procedure provides not only strength but ensures adequate space for a resilient liner if required.
Bone resorption beneath a maxillary complete denture was simulated by the finite element method, assuming that a threshold of compressive strain exists in the alveolar bone above which the resorption occurred. The pattern of predicted resorption was observed when 100 N of force was applied to three positions occlusally, and 20 N was applied facially. Moreover, we observed the effect of rebasing the denture after initial resorption. The results indicate that resorption was initiated on the facial and occlusal surfaces of the alveolar ridge and proceeded palatally. The resorption was greater as the occlusal load point moved facially and when the force was applied in the facial direction. When the load point was toward the facial, rebasing the denture accentuated the resorption, but when the load point was toward the palatal, the resorption was almost the same regardless of rebase. The pattern of simulated bone resorption was similar to that reported from clinical observations, which suggests that the resorption may be associated with compressive strains developed in the alveolar bone. The results argue for the importance of occlusal adjustment of dentures to move the occlusal load point palatally and produce balanced occlusion in protrusion and lateral excursions, especially after a rebase procedure.
The history of complete denture impression procefures has been influenced largely by the development of impression materials from which new ideas and techniques arose. Apparently, some procedures have been devised solely for the promotion of certain impression materials. For the most part, however, impression materials have been developed to accomplish specific goals and, at the time at least, were considered desirable for the purpose.
Fabrication of complete dentures is dependent upon making accurate final impressions that capture the movable tissues in their functional state. Border-molding a custom tray with compound prior to making final impressions is a well established technique for recording these tissues. However, many practitioners avoid or abandon this technique because there appear to be more cost effective and/or easier techniques available. This article reviews proper border-molding procedures for maxillary impressions and graphically demonstrates the difference between impressions made with and without border-molding.
Although the anterior guidance in complete dentures is not really a guide, the arrangement of the anterior maxillary and mandibular prosthetic teeth, defines a propulsive line called the virtual anterior guidance, a part from the cinematic criterias. The influence of this guide on cuspal movement is superior, in all mandibular points, to the influence of the condylar pathway. If this line is not respected, the practitioner may have to do excessive grindings during occlusal adjustments.
Forces required by complete dentures for penetrating some commonly used food items were measured experimentally. These forces were compared with the maximal bite forces of twenty-seven complete denture wearers. Food items that required the greatest forces in direct closure were rye bread (167 N), raw carrot (118 N), boiled meat (80 N), and raw cabbage (74 N). Raw carrot and raw cabbage required the greatest force in straight incision (39 N and 33 N, respectively). Simulated laterotrusion aided most in the penetration of rye bread and boiled meat. The penetration forces in simulated conditions were high compared with the maximal bite forces of the complete denture wearers.
eneral considerations necessary to determine whether a complete denture reline should be attempted or a new denture constructed have been presented. Specific evaluation procedures, including the examination and diagnosis of the patient and the complete denture(s) along with a checklist of complicating factors, have been discussed. Hickey and Zarb have said: "The complicated [nature] of the conditions to be corrected makes [reline] procedures not the simple operations many patients and dentists think they are." The authors emphatically agree.
The effect of the technical quality of complete dentures and the physical condition of the mouth on patients' satisfaction was investigated in 130 patients who received new complete dentures. A moderately positive correlation was found between satisfaction of the patient and quality of the dentures. However, no correlation was found between the satisfaction of the patient and the physical condition of the mouth.
An investigation was carried out into the problems experienced by 114 referred patients with complete dentures who were considered to be difficult or to have difficult prosthodontic problems. The commonest problems were those of pain and lack of retention, due mainly to occlusal discrepancies and excessive VDO. Treatment was carried out on an individual basis with a large proportion of dentures being remade. However, a small number was satisfied by counselling alone without procedural treatment. A diagnostic denture technique was used for particularly difficult cases. This technique showed that, in two cases, technical prosthodontic inadequacies could definitively be excluded as the problem. The overall success rate for treatment was 80 per cent. Further studies on a larger patient sample are needed so that specific problems can be linked to cause and outcome in a meaningful manner.
BACKGROUND: The ability of patients to discriminate thickness can change with time after the insertion of new complete dentures, and this adaptation may differ according to the experiences of the patients. If so, an education program to reinforce the oral functions may be needed. This study was to evaluate patients' ability to discriminate thickness by comparing experienced and non-experienced denture wearers after the insertion of new complete dentures. METHODS: Forty edentulous patients with a skeletal Class I jaw relationship without any temporomandibular disturbances were in the study. After insertion of new complete dentures, all patients were tested for discrimination threshold for interocclusal thickness. The thickness perception test was repeated on days 1, 7, and 30 after the insertion of new dentures. The discriminatory ability was assessed with steel and aluminium foils placed between the upper and lower central incisor teeth. The records included the duration of wearing dentures. The data were subjected to statistical analysis of two-way ANOVA, multiple comparison test and Student's t test. RESULTS: Discrimination of tactile ability significantly increased over 30 days in experienced denture wearers as compared with non-experienced patients (P < 0.001). The difference in thickness perception threshold was statistically significant between the two groups (P < 0.001). CONCLUSION: Adaptation and denture experience can affect thickness discrimination of complete denture wearers.
Twenty-three edentulous patients who had been treated with a mandibular fixed complete denture retained by osseointegrated implants were followed over a 10-year period. Nine of these patients had received a maxillary fixed implant-supported complete denture prosthesis after the initial placement of the mandibular restoration, while the remainder still used a conventional maxillary complete denture. The maximal occlusal force or mastication efficiency index of those having fixed implant-supported prostheses in both arches did not differ markedly from those having only a mandibular restoration. However, at the 3-year examination, lower values were recorded for the self-rated masticatory ability, while higher values were given after 10 years. It was concluded that placement of a mandibular fixed implant-supported prosthesis in dissatisfied complete denture wearers led to a dramatic improvement of masticatory function that was quite acceptable for many patients. However, some patients subsequently demanded a maxillary fixed prosthesis to feel satisfactorily rehabilitated.
Clinical literature details the causes for deformation and failure of acrylic resin complete denture bases. These findings are used to select patterns of high performance polyethylene fiber reinforcement that would best use the properties of the material and improve the mechanical behavior of the prostheses. A technique is described for making reinforced maxillary and mandibular bases with the fibers placed as suggested by the analysis. Microscopic observations of cross sections of reinforced bases revealed good fiber/resin integration and polish.
The Purpose of this study was to determine the effects of complete dentures on alveolar mucosa microcirculation. The alveolar mucosal microcirculation of 17 edentulous subjects was measured by videomicroscope. The variance of the alveolar mucosa microcirculation before and after insertion of the dentures was compared. The results showed that: 7 days after wearing complete dentures, the mucosal blood flow and blood cell velocity of maxillary anterior alveolar ridge crest decreased significantly (P < 0.05), those of labial region of maxillary anterior alveolar ridge increased significantly (P < 0.05), 14 days after wearing complete dentures, the mucosal blood flow and blood cell velocity almost recovered the levels before wearing the dentures. The results can be relative to adjustment the occlusion in the early period of wearing the complete dentures and not wearing the complete dentures at night.
OBJECTIVE: The purpose of this study is to evaluate the effect of therapeutic complete denture in rectifying malmaxillomandibular relation of complete. METHODS: 11 patients were treated with therapeutic complete denture, of which the maxillary premolars and molars were artificial ceramic teeth and mandibular premolar and molar region was just like a splint. The changes before and after the treatment were recorded by mandibular kinesiograph(MKG). The effect was evaluated by self-control comparison. RESULTS: After rectifying, the concentration of the closing locus end position evidently increased, the symmetry of mandible motion significantly improved, CRO-ICO three-dimensional slide range decreased and moreover, the teeth had even and stable contact during sliding. CONCLUSION: The temporary therapeutic complete denture had a fair effect in rectifying malmaxil-lomandibular relation of edentulous patients.
Today, Japan as a society is aging. The average life expectancy of Japanese people is approximately 80 years. One result of this is that preservation of masticatory functions in elderly people has become increasingly important from the viewpoint of quality of life. In the future, the use of dentures in facilitating masticatory functions as a substitute for teeth that are lost during the aging process will assume greater significance. Accordingly, appropriate evaluation and judgment of complete dentures for edentate jaws is crucial. This study was designed to elucidate the effects of the craniofacial form in complete denture wearers on the mode of activity of gnathic functions. First, subjects wearing complete dentures in both the upper and lower jaws were instructed to carry out vertical clenching, and bite force direction was determined. These data were then related to the subject's craniofacial morphology. These results suggest that the bite force direction in complete denture wearers is not affected by gender differences, but is closely associated with lateral craniofacial morphology, and that appropriate setting of occlusal plane and the occluded vertical dimension is extremely important in the preparation of complete dentures.
OBJECTIVE: To evaluate treatment outcomes of mandibular complete denture supported by two endosteal magnetic-attachment implants in edentulous patients with severe mandibular alveolar ridge absorption. METHODS: Eight edentulous patients with severe mandibular alveolar ridge absorption were chosen. Each of them was treated with a complete denture supported by two CDIC implants. The implants were inserted at the areas of two the first premolars respectively. After five months, two magnets were adhered to the inside of the complete dentures. Retention, masticatory efficiency and maximal masticatory force were measured before and after the magnets were adhered and six months later. RESULTS: Statistical analysis revealed that retention, masticatory efficiency and maximal masticatory force were all increased after the magnets were adhered (P < 0.01) and six months later (P < 0.01). CONCLUSION: Retention, maximal masticatory force and masticatory efficiency were significantly increased after the endosteal magnetic attachment implants were applied. It is concluded that mandibular complete denture supported by two endosteal magnetic attachment implants is an effective method for severe alveolar ridge absorption cases.
A technique has been described which uses a polyether impression material for border molding of complete denture impressions. It has the following advantages: 1. There is simultaneous molding of all borders of either the maxillary or mandibular impression. 2. Border molding can be accomplished with one insertion of the tray. 3. Functional movements performed by the patient are used in border molding. 4. The technique is easily mastered.
PURPOSE: To examine the effect of air abrasive particles on the retention of maxillary complete dentures. METHODS: Twenty edentulous subjects, aged 48-72 years with a mean age of 62.2 years were selected. Subjects had questionable satisfaction regarding the retention of their existing maxillary complete dentures, and satisfactory denture bearing tissue with no visible undercuts. Existing dentures were tested for retention before and after air abrasion. Then, new maxillary complete dentures were constructed for them, and tested before and after partial air abrasion. Ten of the subjects continued with a new set of dentures, to test the effect of air abrasion of the entire fitting surface. A specially designed strain gauge force transducer and a strain indicator unit were used to measure forces that required dislodging the denture from its foundation. Retention force was measured before and after the fitting surface of the dentures was uniformly air-particle abraded with 50 microm aluminum oxide abrasive particles under 4 Kg/cm2 of pressure with a quick circling motion at 10-15 mm distance for 30 seconds. RESULTS: The results showed significant improvement in the mean retention forces of the new and the existing well-fitting maxillary complete dentures at all time intervals after air-particle abrasion of part and entire fitting surfaces, while the mean retention forces for the poorly fitting dentures showed only non-significant, slightly increased retention at all time intervals after the fitting surface was air-particle abraded.