The importance of a two-step impression procedure for complete denture fabrication: a systematic review of the literature

Fabrication of complete dentures for an older patient with mobility impairment in three appointments: A dental technique

OBJECTIVE

To describe the clinical procedures of complete denture set fabrication in three appointments.

BACKGROUND

Simplified approaches have proven not to be inferior to conventional ones in terms of quality, patient satisfaction and masticatory ability.

MATERIALS AND METHODS

The patient was a 77-year-old edentulous adult with mobility impairment seeking dental rehabilitation in a small number of appointments due to commuting difficulties.

RESULTS

A set of complete dentures was delivered within three appointments. The second appointment was dedicated to set-up trial due to the patient's aesthetic demands.

CONCLUSION

Under certain circumstances and after a thorough study of each case, dental clinicians may propose the fabrication of complete dentures in a three-appointment protocol incorporating a set-up trial session.

Simplified versus conventional complete dentures: A randomized crossover clinical trial

STATEMENT OF PROBLEM

A simplified approach to complete denture treatment, omitting the border molding and definitive impression appointment, was suggested as an alternative to the conventional approach. However, comparison clinical trials are lacking.

PURPOSE

The purpose of this randomized crossover clinical trial was to assess the satisfaction of edentulous patients and their oral health impact profile when provided with complete dentures fabricated through the simplified or the conventional approach.

MATERIAL AND METHODS

Forty completely edentulous patients seeking complete dentures were randomly divided into 2 groups (n=20). Each group received 2 sets of dentures. The first group received conventionally fabricated complete dentures, and the second group received complete dentures fabricated through the simplified approach. After 2 months, participants rated their overall satisfaction and their satisfaction regarding comfort, retention, stability, and efficiency of mastication and speech on a 100-mm visual analog scale (VAS). Participants also filled out the oral health impact profile for edentulous patients (OHIP-EDENT) questionnaire. Each group was then given the alternate set of dentures and reviewed again after 2 months. The results were analyzed by using the Mann-Whitney U and Wilcoxon-signed rank tests (α=.05).

RESULTS

The simplified complete dentures had significantly higher VAS scores for general satisfaction with maxillary dentures (P=.036), satisfaction with retention of maxillary dentures (P=.002), satisfaction with stability of maxillary dentures (P=.003), and satisfaction with speaking (P=.002). No statistically significant differences were found between the 2 groups regarding the other VAS items or OHIP-EDENT scores (P>.05).

CONCLUSIONS

The simplified denture fabrication approach required fewer appointments and resulted in higher patient satisfaction and similar OHIP-EDENT scores compared with the conventional approach. The simplified approach can be recommended over the conventional approach.

Digital Workflow for a Scleroderma Patient with Microstomia: A Clinical Report

Making impressions in patients with microstomia is often rather problematic due to their restricted mouth opening. Herein, this report describes a novel digital workflow for making impressions with computer-aided design and computer-aided manufacturing (CAD/CAM) custom sectional trays for a 58-year-old female patient with scleroderma and microstomia. CAD/CAM custom sectional trays were made based on digital dentition models from another case with similar arch scale. After the sectional impressions were obtained, the sectional casts were scanned and digitally aligned to form the final dentition models. The removable partial dentures were designed on the final digital models and printed using a 3D printer. This procedure was executed with a successful prosthetic outcome that included good fit and acceptable esthetics. The patient also reported a high level of satisfaction.

In silico evaluation of the peripheral and inner seals in complete denture master impressions using a custom-developed 3D software

OBJECTIVES

Despite the complexity of the edentulous anatomy, little evidence exists as to what impression techniques and materials should be employed for an optimal result. The aim of this in silico study was to evaluate the trueness of peripheral and inner seals of different edentulous jaw impressions.

MATERIALS AND METHODS

Twelve maxillary edentulous participants (male = 8, female = 4; age 68.5 ± 11.7 years) participated in this study. Four different impression materials and techniques, irreversible hydrocolloid (Alginate; Blueprint X-Crème, Dentsply Sirona, PA, USA), polyvinyl siloxane impression (PVS; Aquasil Ultra+ Medium, Dentsply Sirona, PA, USA), and subsequently modified with ZnOE (PVSM) and an optical impression (Optical; 3Shape A/S, Copenhagen, Denmark), were tested against a control impression: low-fusing impression compound border molding (Kerr Corp., CA, USA) followed by a ZnOE impression (ZnOE; SS White impression paste, S.S. White Group, Gloucester, England). All impressions were scanned and analyzed using a custom-built 3D comparison software analyzing the vertical and horizontal trueness.

RESULTS

The vertical discrepancy (peripheral seal) of the impression surface was significantly more true for PVSM than Alginate (p = 0.001), PVS (p = 0.019), and Optical groups (p < 0.001). Where the horizontal discrepancy (inner seal) was compared, the impression surface was more true for PVSM than Alginate (p < 0.001) and Optical (p < 0.001). PVS group was also significantly more true than Optical (p = 0.015).

CONCLUSION

Impression techniques and materials may significantly influence the peripheral and inner seal of an edentulous jaw impression.

CLINICAL RELEVANCE

When using a polyvinylsiloxane impression material for master edentulous impressions, a selective inner seal reline with a conventional zinc oxide eugenol impression paste can improve the inner seal.

Is a two-step impression mandatory for complete denture fabrication on the severely resorbed mandible? A randomized trial on mastication, patient satisfaction and adjustments

OBJECTIVES

To compare one- vs two-step impression procedures for the provision of conventional complete dentures (CCDs) for edentulous individuals with severe mandibular resorption, in terms of (1) masticatory performance and ability; (2) satisfaction with mandibular CCDs; and (3) post-delivery adjustments.

METHODS

Fifty-two patients requiring maxillary + mandibular CCDs were randomly divided into two parallel arms according to the impression method of the mandibular ridge: (SI) single impression with stock trays (irreversible hydrocolloid); (TI) two-step impression in custom trays, with border molding (impression compound) followed by the impression itself (polyether). Mastication performance was evaluated by a colorimetric test, whereas patients answered questions on masticatory ability and satisfaction with mandibular CCDs (100-mm visual analogue scale). The number of post-delivery sessions for adjustments were also quantified. Outcomes were assessed at 3 and 6 months after delivery.

RESULTS

The masticatory performance was similar for both groups, regardless of time (3 months, P = 0.62; 6 months, P = 0.61). No significant difference was found for patient-reported (P > 0.05), i.e. masticatory ability (general ease of chewing and quality of grinding food; ability to chew specific foods), general satisfaction with the mandibular CCD (general satisfaction, comfort, aesthetics, ability to speak and to perform correct cleaning, retention and stability). Both methods resulted in a similar number of post-delivery adjustment sessions [SI: 3.8 (1.7); TI: 3.2 (1.4); P = 0.09].

CONCLUSIONS

Compared to a traditional approach, CCDs obtained from a single impression achieve similar masticatory performance/ability and patient satisfaction, even in patients with severely reabsorbed mandibular ridge. Both methods demand the same amount of post-delivery adjustment.

CLINICAL SIGNIFICANCE

A simplified impression technique which eliminates the secondary impression can provide CCDs of good clinical quality, which influences the OHRQoL, and satisfaction in the same extent they would by a two-step procedure, even for patients with severely reabsorbed mandibular ridges (ClinicalTrials.gov: NCT02339194).

Is a two-step impression mandatory for complete denture fabrication on the severely resorbed mandible? A randomized trial on patient perception and denture quality

OBJECTIVES

To evaluate the effectiveness of CCDs produced by two impression procedures for the mandibular ridge, in patients with severe mandibular atrophy.

METHODS

Fifty-two completely edentulous patients with severely resorbed mandibles were randomly allocated into two groups according to the impression procedure of the mandibular ridge: SI - single impression (stock tray and irreversible hydrocolloid); TI - two-step impression (custom tray, border molding with compound, and polyether). Assessments of oral health related quality of life (OHRQoL, primary outcome) and denture satisfaction were performed by using validated questionnaires. Denture quality was evaluated by means of functional tests.

RESULTS

Regardless of the technique, participants reported better OHRQoL (P < 0.001) in both follow-up periods (3 and 6 months after denture delivery), and groups resulted in similar OHIP-EDENT scores in its different domains (P > 0.05). Between-group differences were insignificant for general satisfaction (3 months, P = 0.699, 6 months, P = 0.392), as well as for aspects such as esthetics, comfort, mastication, speech, and prosthesis retention (P > 0.05). Overall clinical quality of the CCDs (P = 0.383) was similar between-group, as well as in specific aspects - interocclusal distance, occlusion, articulation, retention of the maxillary denture, and stability of both maxillary and mandibular dentures (P > 0.05).

CONCLUSIONS

Mandibular CCDs based on a single impression technique showed quality levels comparable to those generated by a two-step impression, both from the patient and clinician perspective.

CLINICAL SIGNIFICANCE

A simplified impression technique which eliminates the secondary impression can provide CCDs of good clinical quality, which influences the OHRQoL, and satisfaction in the same extent they would by a two-step procedure, even for patients with severely reabsorbed mandibular ridges. (ClinicalTrials.gov: NCT02339194).

Accuracy of Three Impression Materials on the Totally Edentulous Maxilla: In Vitro/In Silico Comparative Analysis

BACKGROUND

This study was aimed at comparing the accuracy of impressions of a reference typodont (RT) reproducing a totally edentulous maxilla made with three impression materials: polysulfide, polyether, and polyvinyl-siloxane.

METHODS

The RT was scanned using a desktop scanner, obtaining a reference scan. Ten impressions for each of the three tested materials were made using a mechanical device with a standardized and consistent modality. A laboratory scanner performed the digitization of each impression. We produced digital models by processing "in reverse" the scans of the physical impressions using a dedicated software, obtaining three groups (n = 10), respectively. The groups were titled: "polysulfide," "polyvinyl-siloxane," and "polyether." The scans in .stl format were imported into Geomagic Control X and then compared to RT to evaluate the accuracy of each scan by calculating trueness and precision in µm. Recorded data were subjected to descriptive statistics.

RESULTS

Trueness (arithmetic proximity) values (95%CI) were: polysulfide = 249.9 (121.3-378.5), polyvinyl-siloxane = 216.8 (123.1-310.6), polyether = 291.1 (219.9-362.3). Precision values (95% CI) were: polysulfide = 261.9 (108.8-415), polyvinyl-siloxane = 209.4 (111.9-306.8), polyether = 283 (227.9-338.1). Statistically significant differences were not detected between the means of the experimental groups, both for trueness and precision.

CONCLUSIONS

The accuracy of the scans obtained from polyvinyl-siloxane, polysulfide, and polyether impressions can be considered comparable in a fully edentulous maxilla.

Effectiveness of a simplified method for final impression in complete denture treatment: A pragmatic clinical trial

PURPOSE

This study aimed to compare two methods for final impression during the fabrication of complete dentures: a traditional method using custom trays (T-group) and a simplified method using the trial denture baseplate (S-group).

METHODS

A pragmatic clinical trial was conducted among edentulous individuals referred for conventional denture treatment. A consecutive sample of edentulous patients was assigned to two groups by cluster randomisation according to the final impression strategy, 30 in the T-group and 38 in the S-group. In the T-group, an auto-polymerising acrylic resin custom tray was used for impression; in the S-group, the final impression was performed using the try-in dentures. For both groups, zinc oxide eugenol paste was used as the impression material. The quality of the dentures was assessed using two rating scales (Functional Assessment of the Dentures and Kapur method). Moreover, clinical time for denture fabrication, number of post-insertion appointments for adjustments, patient satisfaction and post-treatment oral health-related quality of life impacts were also assessed.

RESULTS

There were no significant differences between groups regarding prosthodontic and patient-reported outcomes. The S-group demanded less clinical time (P = 0.002), with a 23.3% mean reduction in clinical time (P = 0.002) and lower number of appointments until the delivery of the dentures (S-group = 4.18 vs T-group = 5.0; P = 0.001).

CONCLUSIONS

This study showed that the alternative method for final impression is less time-consuming and has similar clinical outcomes when compared to the traditional final impression method. Findings suggest that this alternative may be considered when efficiency is a critical issue in healthcare services.

Edentulous jaw impression techniques: An in vivo comparison of trueness

STATEMENT OF PROBLEM

Simplified edentulous jaw impression techniques have gained popularity, while their validity has not yet been evaluated.

PURPOSE

The purpose of this clinical study was to compare the trueness of maxillary edentulous jaw impressions made with irreversible hydrocolloid (ALG), polyvinyl siloxane (PVS), PVS modified with zinc oxide eugenol (ZOE) (PVSM), and an intraoral scanner (TRI) with a conventionally border-molded ZOE impression (control).

MATERIAL AND METHODS

Twelve edentulous maxillary impressions were made with the impression techniques. The analog impressions were scanned using a laboratory scanner, imported into 3-dimensional comparison software, and superimposed against the corresponding control. Trueness was evaluated by calculating the effective deviation known as root mean square (RMS) for the entire surface (ES) and for specific regions of interest such as peripheral border, inner seal, midpalatal suture, ridge, and posterior palatal seal. The secondary outcomes for this study were the patients' perception of the impression techniques. Statistical analyses with the Wilcoxon tests were carried out (α=.05).

RESULTS

For ES, significant differences were found when comparing ALG (1.21 ±0.35 mm) with PVS (0.75 ±0.17 mm; P=.008), PVSM (0.75 ±0.19 mm; P=.012), and TRI (0.70 ±0.18 mm; P=.006) but not among the other groups. Significant differences were found for peripheral border when comparing ALG (2.03 ±0.55 mm) with PVS (1.12 ±0.32 mm; P=.006), PVSM (1.05 ±0.29 mm; P=.003), and TRI (1.38 ±0.25 mm; P=.008), as well as TRI and PVSM (P=.028). Significant differences were also found for inner seal when comparing ALG (0.74 ±0.36 mm) with PVSM (0.52 ±0.13 mm; P=.041), as well as TRI (0.8 ±0.25 mm) versus PVS (0.56 ±0.14 mm; P=.005) and PVSM (P=.005). The difference at the ridge was significant when comparing PVS (0.18 ±0.07 mm) with PVSM (0.28 ±0.19 mm; P=.015) but not among the other groups. A significant difference was also found for posterior palatal seal when comparing PVS (0.55 ±0.41 mm) with PVSM (0.60 ±0.43 mm; P=.034). Patient perceptions showed significantly better satisfaction scores for ALG (1.83 ±2.03) and PVS (3.17 ±2.40) than for TRI (4.08 ±2.71), PVSM (4.58 ±2.35), and ZOE (6.83 ±1.75).

CONCLUSIONS

Edentulous impressions made with PVS, PVSM, and TRI had similar deviations and may yield clinically acceptable results. Irreversible hydrocolloids are contraindicated for definitive impression making in completely edentulous jaws.

Clinical remounting of complete dentures: A systematic review

STATEMENT OF PROBLEM

A recent trend has been to reduce the procedural complexity of complete denture fabrication. Whether the clinical remount step is necessary is unclear.

PURPOSE

The purpose of this systematic review was to assess the relevance of the clinical remount procedure on complete denture outcomes.

MATERIAL AND METHODS

Five electronic databases were searched through to May 2018. The terms "denture*", "dental prosthes*", "equilibrat*", and "remount*" were chosen. The titles and abstracts were screened, and those which met the inclusion criteria were selected for full-text assessment. Studies that only performed the laboratory remount or were not randomized controlled studies were excluded.

RESULTS

After duplicate removal, the database search strategy resulted in a total of 226 potential studies. After the titles and abstracts had been screened and the inclusion and exclusion criteria applied, 10 studies were retrieved for full-text assessment. Four randomized controlled clinical studies were included in the systematic review. A meta-analysis could not be performed because of variation in outcome measures after the clinical remount.

CONCLUSIONS

A clinical remount for complete dentures is recommended on delivery to reduce clinically observed areas of discomfort and reduce the number of recall appointments. The development of a reliable and valid patient satisfaction questionnaire is necessary to determine conclusively whether the clinical remount also improves patient-perceived satisfaction and mastication.

Learning effects of different training models for border molding from the perspective of dental students

BACKGROUND

The aim of this study was to investigate the effects of different practical training models on the comprehension and evaluation of practical training among dental students.

METHODS

The study subjects were all sixth-year dental students at our institute, and the study took place over three consecutive years (n = 58, 63, and 65, respectively). In practical training, all students learned border molding, and practical models were modified each year from plaster models to silicone models and then to silicone models mounted in mannequins. Immediately after completing clinical training, all students were asked to complete questionnaires consisting of 21 items regarding their overall practical training and their clinical comprehension of border molding. All items were rated on a five-point Likert scale, and in order to reduce the large number of interrelated questions, exploratory factor analysis was carried out using maximum likelihood estimation with promax rotation (κ = 4) and Kaiser normalization. The number of factors was chosen using the Kaiser-Guttman rule, which states that the eigenvalue should be larger than 1, and the scree plot criteria. Items that scored less than 0.25 in communality and exhibited factor loading greater than 0.35 for more than one item were excluded. The defined factors were analyzed for the plaster models, the silicone models alone, and the silicone models with mannequins using the Kruskal-Wallis test and follow-up tests using Bonferroni-corrected Mann-Whitney U tests. The significance level was set at p < 0.05.

RESULTS

Exploratory factor analysis identified the following three factors: "knowledge of border molding"; "contents of practical training"; and "personal learning attitude". The students who used silicone models and mannequins gave significantly better evaluations on the "knowledge of border molding" (p < 0.001, both) and "contents of practical training" (p = 0.046, p < 0.001, respectively) subscales than those who used plaster models. No significant differences were observed between those who used silicone models and those who used mannequins. Moreover, no significant differences were found on the "personal learning attitude" subscale among students for any model.

CONCLUSIONS

The change in practical training models from plaster to silicone improved student evaluations of border molding training.

Patient satisfaction with occlusal scheme of conventional complete dentures: A randomised clinical trial (part I)

BACKGROUND

Occlusal scheme can affect denture retention, stability, occlusal force distribution, aesthetics, masticatory function, patient comfort and general patient satisfaction with dentures.

OBJECTIVES

This study aimed to compare the patient satisfaction with 3 types of complete denture occlusion including fully bilateral balanced occlusion (FBBO), newly presented buccalised occlusion (BO) and lingualised occlusion (LO).

METHODS

In this parallel randomised clinical trial, new conventional complete dentures were fabricated for 86 volunteers. Participants were randomly allocated to 3 groups with 3 different occlusal schemes. All patients were recalled at 1 and 3 months after delivery for data collection. The 19-item version of Oral Health Impact Profile for Edentulous Patients questionnaire was used in this study. The visual analogue scale (VAS) was used for assessment of the prosthodontist's attitude towards denture quality, patient's attitude towards different occlusal schemes and evaluation of patient satisfaction. Data were analysed using the Wilcoxon signed rank test, the Kruskal-Wallis test and the post hoc Dunn test via SPSS version 18.0 (P ≤ .05).

RESULTS

Eighty-six patients completed the study, and their data were analysed (mean age ± standard deviation = 57.78 ± 9.98 years). The only significant difference when comparing the 3 groups was physical pain, which was significantly higher in FBBO group. No significant differences were found for the VAS scores of patient and prosthodontist satisfaction or the domain scores among the 3 occlusal schemes either at 1 or at 3 months post-delivery. The VAS score of patient satisfaction and prosthodontist satisfaction increased at third compared to first month after delivery.

CONCLUSION

The results of this randomised clinical trial provided evidence that BO is as effective as LO for the fabrication of complete dentures.