Full Palatal Coverage Research Articles

Evaluation of Clinical Periodontal Parameters of Abutment Teeth Supporting Distal-Extension Base Removable Partial Dentures: A Cross-sectional Study.

To assess the clinical periodontal status of abutment teeth in regards of different design components of distal-extension removable partial dentures. Subjects (N=100) with acrylic or cobalt-chromium distal-extension removable partial dentures were enrolled and their periodontal parameters plaque and gingival indices [PI, GI], probing depths [PD], clinical attachment loss [CAL] and a mobility index [MI] evaluated. Denture base type, major connector, occlusal rests position, design of direct retainers, retention, stability and denture wearing habits were further evaluated. Acrylic RPDs were associated with higher mean±SE PI [1.70±0.74], GI [1.76±0.55], PD scores [2.47±1.02 mm] and CAL values [4.46±2.11 mm] compared to CO-CR RPDs [p⟨0.05]. For abutments, the PI [1.6±0.83], GI [1.72±0.57], PD [2.32±1.03] and CAL [4.26±2.08] were higher than their non-abutments counterparts [p⟨0.05]. CAL scores were found to be significantly higher for mandibular abutments compared to maxillary ones [P=0.002]. The highest PI [1.83±1.10] and GI [2.00±0.00] scores were associated with lingual bars and horse-shoe connectors, respectively. Full palatal coverage and lingual plates were associated with the highest PD [2.80±0.48] and CAL [4.70±0.37] scores. Acrylic RPDs, type of major connector, wrought wire clasps and distal occlusal rests may be considered as risk factors for periodontal disease progression in distal-extension removable partial denture wearers.

Effect of Liquorice Candies on Remineralization of Initial Enamel Carious Lesion.

Glycyrrhiza glabra (G. glabra), known as liquorice root is one such herbal remedy that has been shown to have immense potential in the treatment of orofacial diseases. To evaluate the remineralizing potential of liquorice extract on initial enamel carious lesions. An in vitro and in vivo study was conducted, wherein the sound-extracted human premolars were sectioned longitudinally and into enamel blocks of size 4 × 4 mm. Enamel blocks were demineralized to produce artificial carious lesions. In vitro study, the demineralized enamel block was exposed to artificial saliva for 5 minutes and artificial saliva containing liquorice for 4 minutes 14 times in a sequential manner. An in vivo study was carried out on six volunteers aged between 6 and 12 years. The demineralized enamel block was inserted into the 5 × 5 mm window created on the full palatal coverage appliance. Patients were given commercially available liquorice candies (Ricola) to consume for 7 days twice daily. The remineralization potential of liquorice on demineralized enamel block was assessed using confocal microscopy analysis. Liquorice extract containing candies showed visual remineralization of the demineralized area on the enamel surface through confocal images. Liquorice extract possesses remineralizing potential with its other medicinal properties. . Pooja HR, Nagar P, Mascarenhas AN, et al. Effect of Liquorice Candies on Remineralization of Initial Enamel Carious Lesion. Int J Clin Pediatr Dent 2023;16(S-1):S33-S38.

Flangeless horseshoe maxillary complete denture: a prosthodontic solution to maxillary tori

Tori may present difficulties in achieving a retentive prosthesis with full palatal coverage. Management of tori in such cases may involve attempting to avoid coverage of the torus, providing relief over the torus, or surgical reduction/removal. This article presents a case where a patient who presented with a large maxillary torus was managed with a non-surgical approach, which enabled provision of a successful prosthesis. Dental practitioners could consider this approach for selected cases. CPD/Clinical Relevance: Thorough prior planning and a modified denture design can be used to provide an effective clinical solution for maxillary and mandibular tori.

Four-implant-supported overdenture treatment in the maxilla. Part II: Speech- and oral health-related quality of life in patients with implant-supported overdentures in the maxilla-A prospective 3-year follow-up.

Implant-supported overdentures (IOD) are becoming a more commonly used treatment in the dental practice and it risks causing speech problems. The aim of this study was investigating the changes in speech, satisfaction with speech, and overall oral health-related quality of life (OHRQoL) in edentulous patients during and after treatment with maxillary IODs. Twenty-one patients receiving an IOD participated in speech assessment. They were examined preoperatively with their conventional denture (CD) with full palatal coverage, after connection of the implant-bar connected denture, without palatal coverage, and 3 years thereafter. The examination included assessment of articulation in speech, OHRQoL based on total OHIP-14, and satisfaction with overall oral health and speech (visual analogue scale). There was a reduction in mean number of articulation disorders from 1.00 at baseline to 0.55 at connection, although statistically insignificant (p=0.059). Especially the /s/ sound is vulnerable. At 3 years follow-up, still 6/16 (37.5%) of the patients suffered from this speech problem. Overall satisfaction improved from 64.05/100 at baseline to 82.95/100 at connection (p=0.008) and remained unchanged with 81.69/100 after 3 years follow-up. Patients' satisfaction with speech increased from 70.62/100 with CD to 82.63/100, 3 years follow-up (p=0.009). Total OHIP-14 decreased from 21.45/56 with CD to 8.00/56 (p < 0.001) with IOD and 6.13/56 3 years after connection (p=0.001). Significant improvement of all seven domains in OHRQoL was observed with IOD compared to CD. Patients treated with maxillary IODs show improved OHRQoL 3 years after connection of the IOD compared to the CD. Even though patients reported improvement of satisfaction and OHRQoL, articulation disorders were still present, suggesting that patients should be informed about possible speech issues.

Speech evaluation during maxillary mini-dental implant overdenture treatment: A prospective study.

Large proportions of patients are edentulous and wear removable dentures leading to reduced functional comfort and less oral health‐related quality of life. Satisfaction with the oral situation after implantation depends on the outcome in eating comfort, speech comfort and aesthetics. Modification in form and location of the teeth may affect speech. The aim of this study is to determine speech, oromyofunctional behaviour, satisfaction with the treatment and the impact on quality of life of the horse‐shoe overdenture retained by mini‐dental implants (MDIs) in the maxilla. This prospective multicentre cohort study included 32 patients for treatment. 5 to 6 implants were placed, traumatically piercing the mucosa. Patients were evaluated three times during treatment (pre‐operatively with conventional prosthesis including full palatal coverage (CD), post‐operatively with provisionally relined CD and with horse‐shoe overdenture on MDI). The assessment included a phonetic evaluation, examination of oromyofunctional behaviour, evaluation of the impact on quality of life (OHIP‐14) and a rating of satisfaction with the treatment and speech on a visual analogue scale. Several speech sounds are found to be disturbed before treatment. In the next two stages of the treatment, the number of speech issues decreases. In the final stage, ten people show minor speech problems, especially with the /s/ sound. In this stage, seven people still present with oromyofunctional problems, especially whistling problems. In this last stage, people are very satisfied with the treatment (83%) and with speech (84%). The impact on quality of life is low (8.23/56).

Finite element analysis on stress distribution of maxillary implant-retained overdentures depending on the Bar attachment design and palatal coverage.

PURPOSEThe purpose of this study was to determine the effect of anchorage systems and palatal coverage of denture base on load transfer in maxillary implant-retained overdenture.MATERIALS AND METHODSMaxillary implant-retained overdentures with 4 implants placed in the anterior region of edentulous maxilla were converted into a 3-D numerical model, and stress distribution patterns in implant supporting bone in the case of unilateral vertical loading on maxillary right first molar were compared with each other depending on various types of anchorage system and palatal coverage extent of denture base using three-dimensional finite element analysis.RESULTSIn all experimental models, the highest stress was concentrated on the most distal implant and implant supporting bone on loaded side. The stress at the most distal implant-supporting bone was concentrated on the cortical bone. In all anchorage system without palatal coverage of denture base, higher stresses were concentrated on the most distal implant and implant supporting bone on loaded side.CONCLUSIONIt could be suggested that when making maxillary implant retained overdenture, using Hader bar instead of milled bar and full palatal coverage rather than partial palatal coverage are more beneficial in distributing the stress that is applied on implant supporting bone.

Contribution of the palate to denture base support: an in vivo study.

The aim of this study was to examine the contribution of the palate to denture base support. Four subjects with tooth- or implant-supported maxillary overdentures were enrolled. Recordings (strain values converted to load values) were performed using miniature strain gauges and force transducers for the following conditions: metal framework only (A), denture base with full palatal coverage (B), and denture base without palatal coverage (C). The palatal-supporting ratio (PSR) was calculated using the equation PSR = (B - C) / A. The PSR values were less than 10% in all subjects, suggesting that the palate plays a minimal role in denture base support.

Mechanical Analysis of a Palateless Denture

The purpose of this study was to compare the strain of complete dentures with and without full palatal coverage and to determine the effect of reinforcement. Three types of maxillary complete dentures (with palate, without palate, and without palate but with reinforcement) were fabricated, and reinforcements were made from a cobaltchromium alloy. Strain gauges were attached to the polished surface, and a vertical load was applied in the region of the first premolar and first molar. The strains were statistically compared. The greatest strain occurred on the anterior palatal surface and was tensile in the denture with palatal coverage and compressive in the denture without palatal coverage. Significantly less strain occurred in dentures with reinforcement than without reinforcement.

Marginal bone loss around unsplinted mini-implants supporting maxillary overdentures: a preliminary comparative study between partial and full palatal coverage.

To evaluate and compare marginal bone loss around mini-implants supporting maxillary overdentures with either partial or full palatal coverage. Nineteen edentulous patients complaining of retention problems involving their maxillary dentures were randomly allocated in two groups. Group I (n = 10) received maxillary dentures with full palatal coverage, and group II (n = 9) received maxillary dentures with partial palatal coverage. In total, 114 mini-implants (6 per patient) were inserted using the nonsubmerged flapless surgical approach and loaded immediately with maxillary overdentures. Each implant was evaluated at the time of initial prosthetic loading and at 6, 12, and 24 months thereafter. Radiographic evaluation was performed in terms of vertical and horizontal bone loss. Implant mobility (via Periotest values) was measured using a Periotest device, and patient satisfaction was evaluated with a visual analog scale. The cumulative survival rate was calculated using Kaplan-Meier analysis. After 2 years, the mean vertical bone loss in groups I and II was 5.38 and 6.29 mm, respectively, while the mean horizontal bone loss in groups I and II was 1.52 and 1.93 mm, respectively. Most bone resorption occurred within 6 months after overdenture insertion in both groups. Group II recorded significant higher vertical bone loss and Periotest values than group I at all observation times. The cumulative survival rates of the mini-implants were 78.4% and 53.8% for groups I and II, respectively. All patients were satisfied with their maxillary overdentures in terms of retention and chewing ability. Rehabilitation of edentulous maxillae with unsplinted mini-implants supporting overdentures and in particular with a combination of partial palatal coverage is not recommended because of excessive marginal bone resorption and the higher failure rate of mini-implants than was expected.

An Implant-Retained Maxillary Overdenture to Obturate a Patent Oronasal Communication: A Case Report

This is a case report of dental prosthetic treatment of a 72-year-old patient with cleft palate with a persisting oral nasal communication in the anterior hard palate. The remaining teeth were extracted, and dental implants were surgically placed in the maxilla and mandible to retain removable overdentures. The maxillary complete overdenture had full palatal coverage as opposed to partial coverage. It was retained by 5 implants with low-profile light retentive retainers. The mandibular overdenture was retained with 4 implants of different diameters and brands. Apparent parameters for successful treatment of a removable maxillary overdenture are as follows: denture flanges, flat or lingualized occlusal scheme, light low-profile retainer retention, maximum implant positional spread with parallel placement, and a minimum of 4 rough-surfaced, long, wide implants placed in denser-type bone sites.

Use of a removable healing plate after exposure of an unerupted incisor with an apically repositioned flap

In the management of a superficially-placed, labially-positioned, non-erupted maxillary permanent incisor tooth we favour an apically repositioned flap, the advantage of which is preservation of the mucogingival complex.1 We then fit a removable healing plate to ensure patients’ comfort and to prevent mucosal re-growth. The plate has full palatal coverage and is retained by Adam's or Delta clasps, usually engaging the first permanent molar teeth (Fig. 1). The plate is made on a model produced from an alginate impression of the patient's maxillary arch, taken 2 weeks preoperatively.

Evaluation of dental arch reproduction using three-dimensional optical digitization

Statement of problem Numerous investigations have been done to determine the most accurate method to reproduce a dental arch. Investigations have used different definitive cast configurations, materials, and measuring techniques to evaluate dimensional change, leaving clinicians undecided as to the most accurate method to reproduce a dental arch. Purpose of study The purpose of this investigation was to evaluate the effect of impression tray selection on accuracy of reproductions of a dental arch using a 3-dimensional optical digitizer. Materials and methods Impressions were made of a stone cast of a dental arch using vinyl polysiloxane impression material in custom and stock impression trays (n=12). Custom trays, designed with full palatal coverage, were fabricated on a separate standard stone cast using 2 layers of pink baseplate wax as the spacer and tissue stops on 1 anterior tooth and both first molar teeth. Impressions were poured with type IV gypsum and allowed to set with the tray inverted (n=5) or not inverted (n=5). The standard cast and resulting casts were digitized using an optical digitizer. Custom software was used to align and process the 3-dimensional images created by the digitizer. Each image was superimposed onto the standard cast image, curves were created of the percent of points less than a defined distance between the 2 superimposed images, and the area under the curve was calculated. A weighted average area was calculated for each cast, and these values were analyzed using a 2-way ANOVA (α=.05). Results The main effect of tray type, laboratory setting technique, and the interaction between these 2 characteristics was analyzed. None of these effects was significant. Conclusion The differences in accuracy of reproductions of a dental arch, regardless of the impression and laboratory techniques, were not significant when evaluated using a 3-dimensional optical digitizer.

Use of a removable healing plate in establishing successful exposure of palatally impacted canines

The healing plate is removable with full palatal coverage and uses Adam’s cribs or ball clasps for retention, usually engaging the first permanent molars (Fig. 1). It is made on a model produced from an alginate impression of the patient’s upper dental arch, taken 2 weeks preoperatively. The plate is tried before exposure of the impacted canines and any minor necessary adjustments made. After the canine has been exposed, a periodontal bandage containing 80% zinc oxide paste and 9% magnesium oxide is placed over the operative site. The healing plate is then fitted directly over the periodontal bandage. Patients are instructed about oral hygiene, with emphasis on the regular use of 0.2% chlorhexidine mouthwash.

Retention of maxillary implant overdenture bars of different designs

Statement of Problem. The specific degree of retention for overdenture attachments is unknown in relation to design, location, and alignment to supporting dental implants. Purpose. The purpose of this study was to evaluate the initial retention characteristics of 5 implant maxillary overdenture designs under in vitro dislodging forces. Material and Methods. A simulated edentulous maxilla was fabricated with 4 screw-type 3.75 × 13-mm implants anteriorly. Five overdenture designs with the following attachments were evaluated: 4 plastic Hader clips with an EDS bar; 2 plastic anterior Hader clips with an identical EDS bar; 2 Hader clips with 2 posterior ERA attachments; 3 Zaag attachments on a bar; and 4 Zaag attachments with no bar. Overdentures were fabricated with full palatal coverage. Each design was subjected to 10 consecutive retention pulls on a universal testing machine. Data were subjected to analysis of variance and t tests to determine differences. Results. The highest average value after 10 pulls was 19.8 lb for the combination ERA and Hader clip design. The lowest retentive values were recorded for the 2 and 4 Hader clip designs (5.08 ± 0.89 lb and 5.06 ± 0.67 lb, respectively). Retention decreased over the course of consecutive pulls for all designs, especially for the most retentive designs. The smallest retention decrease occurred with the least retentive designs. Conclusion. The results of this in vitro study suggest that the precise selection and placement of attachments may affect the clinical success of maxillary implant-retained overdentures. (J Prosthet Dent 2001;86:603-7.)

Palatal extension of removable prostheses related to implant positions.

Once the decision has been made to construct a maxillary implant-supported overdenture prosthesis, implant location and number are important determining factors for palatal design. Eight clinical scenarios are described. Four cases require full palatal coverage, and four cases permit modified palatal coverage. Only two, with an increased number of implants and more posterior locations, permit a completely open palatal design similar to fixed prostheses.

Retention of complete maxillary dentures related to soft tissue function

The influence of free tongue, lip, and cheek function on the retention of complete maxillary dentures was investigated for five experienced denture wearers. Test dentures were designed with full palatal coverage and functionally determined filling in of the vestibular sulcus. The front teeth were arranged primarily to meet cosmetic demands--that is, anterior to the top of the residual alveolar ridge. Retention was measured as resistance to dislodgement-provoking loads applied vertically to the incisive edge of the central incisors, using a miniature bite force recorder. All the participants were able to load their front teeth with 35 N or more without loss of retention. None of them experienced denture dislodgement provided the tongue, lips, and cheeks wee allowed to act freely. If the peripheral soft tissues were separated from the vestibular denture flange, no obvious effect on denture retention could be detected. Physically preventing the tongue from pressing against the posterior part of the denture reduced the retention significantly. Measurements of anterior loads tolerated after stepwise reductions of the denture extension indicated that the tongue acted primarily by pressure against the tuber regions. Tongue pressure against the central parts of the palate and lip or cheek pressure against the vestibular flange seemed to be of less importance.

Retention of complete maxillary dentures as a result of changes in design.

The influence of complete maxillary denture design on retention was studied under clinical conditions simulating chewing. Five persons with an edentulous maxilla and a natural dentition of at least 10 teeth in the mandible participated. Retention was measured with a miniature bite force sensor. The occlusal load required to provoke denture dislodgement was recorded. The general principles of denture design were as follows: the bicuspids and molars were set on top of the residual ridge; the thickness of the denture borders was determined functionally; and the palate was covered to the vibration line, without attempts at border compressions. The details that were changed to evaluate their influence on denture retention were as follows: the point of attack of the dislodgement-provoking load alternated between three distinct pits, situated 2 mm apart in the buccopalatal direction on the occlusal surface of the first right bicuspid; the vestibular denture border on the left side was reduced stepwise to 75%, 50%, and 25% of its original thickness; and the distal extension of the palatal denture border was shortened stepwise (2 + 2 mm, as measured in the midline). Measurements pertaining to one specific problem were carried out within a period of 2 h. The results confirmed the concepts that lingualized occlusal contact, functionally determined filling in of the vestibular sulcus, and full palatal coverage to the vibration line all have a positive influence on the retention of complete maxillary dentures.

The effects of age and full palatal coverage on oral stereognostic ability

A number of studies have investigated the oral sensory abilities of denture wearers. Many techniques have been utilized, including discriminations of thickness,’ hardness,’ texture,’ size,’ oral stereognosis ability,,‘-” and oral manipulative ability.‘+ I2 These studies have had inconsistent results, with some investigators reporting significant alterations in oral sensory abilities and others finding no such changes. Any reported change in oral sensory ability may be confounded by a number of variables not specifically related to the ability in question. One such factor is the test itself, which may not be adequately sensitive to detect altered oral sensory function. For example, in evaluating discriminative ability for hardness,’ it was possible to discriminate clearly between denture wearers and nondenture wearers when testing with hard rubber disks but not with soft rubber disks. Another major variable that has not been adequately controlled in previous studies of oral sensory ability is age. Most denture wearers are older, and sensory discrimination is highly age dependent. I.‘, ‘-+ A third factor which must be considered is the role of palatal receptors in the performance of the specific task being tested. Numerous studies of subjects with abnormal oral anatomy have suggested that the palate plays a significant role in oral sensory tasks, including stereognostic ability. Specifically, patients with abnormal palatal vaults secondary to gonadal dysgenesis and pseudohypoparathyroidysm’5, “I consistently demonstrate abnormal oral stereognostic ability. Some evidence also suggests that patients

Occlusal acrylic index used to observe palatal bone cuts

The use of an acrylic occlusal index prior to wiring a full palatal coverage splint into place offers an easy way to check for “hang-up” areas and help in placement of bone grafts while the segments are held in the predetermined position.

Subjective reactions to major connector designs for removable partial dentures

Simlated partial denture frameworks were fabricated for 12 dentists (subjects) who had intact dentitions and who had intact dentitions and who had had no previous experience in wearing partial dentures. The outline of the major connectors was modified during a 1 week interval. The data obtained from questionnaires brought about the following conclusions: 1. Preferences in maxillary major connector design were as follows: (1) broad posterior strap, (2) anteroposterior bar, (3) ring-type design, and (4) full palatal coverage. 2. The mandibular lingual bar was chosen over the lingual plate by a 3:1 ratio. 3. The natural palatal metal finish was perferred to the highly polished finish. 4. Metal borders parallel to tongue movement were better tolerated than those lying transverse. 5. Thickening of the posterior strap to permit its narrowing was not clinically feasible. 6. In general, patients adapted best to major connectors that covered the least amount of soft tissues.