A randomized controlled trial of the different impression methods for the complete denture fabrication: Patient reported outcomes

Oral health-related quality of life and patient satisfaction using three-dimensional printed dentures: A crossover randomized controlled trial

OBJECTIVES

This crossover randomized controlled clinical trial (RCT) aimed to evaluate the clinical applicability of three-dimensional printed dentures (CAD-3DPs) by comparing two fabricated complete dentures, CAD-3DPs and conventional complete dentures (CCDs), and assess the non-inferiority of CAD-3DPs. The hypothesis was that CAD-3DPs would be inferior to CCDs in terms of the oral health-related quality of life (OHRQoL) and patient satisfaction.

METHODS

This single-blind RCT was conducted at two university hospitals. The participants included adult patients with edentulous maxillary and mandibular arches, who had existing complete dentures and were willing to use new complete dentures. Eighteen participants were assigned to two groups: CCD-CAD-3DP and CAD-3DP-CCD, based on the order of denture delivery. Both sets of maxillary and mandibular CCDs and CAD-3DPs were delivered to all the participants. The OHRQoL using Oral Health Impact Profile for Edentulous Patients (OHIP-EDENT-J) was considered the primary outcome. General satisfaction using a 100-mm visual analog scale was also evaluated as a suboutcome.

RESULTS

Based on the non-inferior test on the total score of the OHIP-EDENT and each score of the seven conceptual subdomains, the lower limit of the 95 % confidence interval was < 2.65 in seven domains. Therefore, CAD-3DP was judged to be non-inferior to CCD. Patient satisfaction was not significantly different between the CCD and CAD-3DP groups (p > 0.05).

CONCLUSIONS

This RCT revealed that CAD-3DP is comparable to CCD based on the OHIP-JDENT scores and patient satisfaction.

CLINICAL SIGNIFICANCE

CAD-3DP is clinically applicable and comparable to CCD in terms of patient-reported outcomes.

In vitro evaluation of the impact of intraoral scanner, scanning aids, and the scanned arch on the scan accuracy of edentulous arches

PURPOSE

To assess the accuracy of complete maxillary and mandibular edentulous arch scans obtained using two different intraoral scanners (IOSs), with and without scanning aids, and to compare these results to those obtained using conventional impression methods.

MATERIALS AND METHODS

Two IOSs were used (TRIOS 4 [TRI] and Emerald S [EMR]) to scan maxillary and mandibular typodonts. The typodonts were scanned without scanning aids [TRI_WSA and EMR_WSA groups] (n = 10). The typodonts were then scanned under four scanning aid conditions (n = 10): composite markers [TRI_MRK and EMR_MRK groups], scanning spray [TRI_SPR and EMR_SPR groups], pressure indicating paste [TRI_PIP and EMR_PIP groups], and liquid-type scanning aid [TRI_LQD and EMR_LQD groups]. Conventional impressions of both arches were also made using irreversible hydrocolloids in stock trays [IHC] and using polyvinyl siloxane (PVS) impression material in custom trays (n = 10) which were digitized using a laboratory scanner. Using a metrology software program, all scans were compared to a reference scan in order to assess trueness and to each other to assess precision. Trueness and precision were expressed as the root mean square (RMS) of the absolute deviation values and the statistical analysis was modeled on a logarithmic scale using fixed-effects models to meet model assumptions (α = 0.05).

RESULTS

The main effect of arch (p = 0.004), scanner (p < 0.001), scanning aid (p = 0.041), and the interaction between scanner and scanning aid (p = 0.027) had a significant effect on mean RMS values of trueness. The arch (p = 0.015) and scanner (p < 0.001) had a significant effect on the mean RMS values of precision. The maxillary arch had better accuracy compared to the mandible. The TRIOS 4 scanner had better accuracy than both the Emerald S scanner and conventional impressions. The Emerald S had better precision than conventional impressions. The scanning spray and liquid-type scanning aids produced the best trueness with the TRIOS 4 scanner, while the liquid-type scanning aid and composite markers produced the best trueness for the Emerald S scanner.

CONCLUSION

The scanned arch and the type of scanner had a significant effect on the accuracy of digital scans of completely edentulous arches. The scanning aid had a significant effect on the trueness of digital scans of completely edentulous arches which varied depending on the scanner used.

Evaluation of open-face maxillary complete denture for patients with prominent premaxilla: a crossover study

BACKGROUND

The establishment of good facial esthetics is one of the main objectives of complete denture construction. Unfortunately, it may be the caused issue for patients having a prominent premaxilla due to excessive lip support by the labial flange of the maxillary denture. Open-face dentures (OFD) may suggest suitable prosthetic management for these patients. However, clinical evidence regarding the efficiency of OFD is scarce.

METHODS

A total of 38 completely edentulous participants having prominent premaxilla and skeletal class I Angle's classification were enrolled in this study. Each participant received a mandibular complete denture and 2 opposing maxillary dentures; conventional (CD) and open-face (OFD). On the day of denture insertion, the participants were divided into 2 groups; CD-OFD and OFD-CD where CD-OFD group was instructed to use the mandibular denture and the maxillary CD for 3 months and then to use the maxillary OFD for another 3 months after a wash-out period of 2 weeks. While group OFD-CD was instructed to use the mandibular denture and the maxillary OFD for 3 months then to use the maxillary CD for another 3 months after a wash-out period of 2 weeks. The dislodging force of the maxillary dentures was evaluated using the universal testing machine and the patient perception of retention, esthetics, and comfort was evaluated using the Visual Analogue Scale (VAS). Evaluation was carried out 1 day, 1 month, and 3 months after denture insertion. The Student t-test was used to compare the 2 maxillary dentures and the intervals for each denture were compared by using the ANOVA test with repeated measures followed by a Post Hoc test (adjusted Bonferroni) for pairwise comparison.

RESULTS

The significance of the obtained results was judged at the 5% level (P value). The dislodging force and patient perception of retention did not show significant differences between the 2 dentures, while the perception of esthetics showed significant differences throughout the follow-up period. Perception of comfort showed an insignificant difference only at the 3-month interval.

CONCLUSIONS

Open-face maxillary dentures can be a suitable alternative for patients with prominent premaxilla to achieve satisfactory retention, aesthetics, and comfort.

Patient-reported outcome and cost-effectiveness analysis of milled and conventionally fabricated complete dentures in a university clinic: A retrospective study

STATEMENT OF PROBLEM

The custom disk is a novel method of complete denture fabrication; however, patient-reported outcomes and fabrication costs are unknown.

PURPOSE

The purpose of this retrospective study was to evaluate general patient satisfaction with complete dentures fabricated through the custom disk method. In addition, a comparative cost-effectiveness analysis was conducted for the custom disk method and conventional removable complete dentures.

MATERIAL AND METHODS

Complete dentures were fabricated for 44 edentulous participants by using the custom disk method (n=20) or the conventional removable complete denture (n=24). General patient satisfaction was measured by using visual analog scales before and after denture fabrication and compared by using the Wilcoxon signed-rank test (α=.05); the fabrication cost for each method was investigated and compared by using the Mann-Whitney U test (α=.05). Cost-effectiveness was analyzed with the incremental cost-effectiveness ratio as incremental cost per change in general patient satisfaction for the custom disk method with respect to the conventional removable complete denture.

RESULTS

The median general patient satisfaction with the custom disk method and conventional removable complete denture after the intervention was 84.0 mm and 91.0 mm, respectively. General patient satisfaction with the custom disk method was significantly higher after the intervention (P=.002). The median labor costs for the custom disk method and conventional removable complete denture were 24 516 and 36 583 Japanese yen, respectively, and the difference was statistically significant (P<.001). The median of the total cost of the custom disk method and the conventional removable complete denture was 41 104 and 45 276 Japanese yen, respectively, and the difference was statistically significant (P=.004). The incremental cost-effectiveness ratio was -251.4.

CONCLUSIONS

The custom disk method improved general patient satisfaction. The labor and total costs of the custom disk method were significantly lower than those of the conventional removable complete denture. The incremental cost-effectiveness ratio demonstrated that the custom disk method was more cost-effective than the conventional removable complete denture.

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.

Performance of complete dentures fabricated with the simplified and the traditional technique: A randomized clinical trial

STATEMENT OF PROBLEM

The simplified technique has been recommended for the fabrication of removable complete dentures. However, a consensus regarding the performance of the simplified and the traditional techniques is lacking.

PURPOSE

The purpose of this randomized clinical trial was to compare the performance of prostheses fabricated with the simplified and the traditional techniques.

MATERIAL AND METHODS

Sixty participants were recruited and randomized into 2 groups: traditional technique (control group) and simplified technique (experimental group). The assessments were performed before treatment (baseline) and 2 and 4 months after adaptation to the new complete dentures. The variables evaluated were satisfaction, oral health-related quality of life (OHRQoL) by using the Brazilian version of the OHIP-EDENT, the quality of the prostheses, and, for the functional assessment, the masticatory performance and swallowing threshold. The data were analyzed by the Fisher exact test, the Mann-Whitney test, and the generalized equations estimating (GEE) method.

RESULTS

At baseline, the mean ±standard deviation quality of the prostheses was 5.3 ±2.3 for the traditional technique and 4.9 ±2.3 for the simplified technique, and at 4 months, it was 9.3 ±0.9 and 9.1 ±0.9, respectively. For masticatory performance, the mean ±standard deviation X50 at baseline was 5.7 ±1.4 for the traditional technique and 5.7 ±0.9 for the simplified technique, and at 4 months, it was 3.8 ±1.2 and 3.7 ±0.9, respectively. The mean ±standard deviation OHRQoL at baseline was 14.1 ±8.6 for the traditional technique and 12.5 ±9.4 for the simplified technique, and at 4 months, it was 3.2 ±4.3 and 2.6 ±5.1, respectively. The mean ±standard deviation satisfaction at baseline was 9.5 ±3.9 for the traditional technique and 9.3 ±4.2 for the simplified technique; after 4 months, it was 14.8 ±2.0 for both techniques. There was a significant improvement (P<.05) for all variables in the study when comparing them at the baseline to those at the evaluation after provision of new complete dentures. There was no significant difference in all analyzed variables (P>.05) between the 2 techniques for prosthesis fabrication.

CONCLUSIONS

The simplified technique appears to be a suitable alternative to the traditional technique for the fabrication of complete dentures, with similar performance.

Patient satisfaction with conventional dentures vs. digital dentures fabricated using 3D-printing: A randomized crossover trial

PURPOSE

Evidence regarding the performance of digital dentures (DDs) fabricated using 3D printing is insufficient. This study aimed to evaluate patient satisfaction with conventional dentures (CDs) and DDs fabricated using 3D printing.

METHODS

This randomized controlled trial was conducted between November 2017 and May 2020. In the CD-DD group, CDs were fabricated before DDs, while the protocol was reversed in the DD-CD group. The primary outcome was patient satisfaction, quantified using a 100-mm visual analog scale, which assessed chewing efficiency, pain, stability, retention, comfort, esthetics, ease of cleaning, phonetics, and general satisfaction. Secondary outcomes were quality of life (QOL), number of visits, time required for definitive denture fabrication, number of adjustment appointments, and time required for denture stabilization after denture delivery.

RESULTS

Patient satisfaction with CDs was superior in terms of phonetics, ease of cleaning, stability, comfort, and general satisfaction. Secondary outcomes such as social disability and the number of clinic visits were significantly lower in patients with DDs. However, the two groups showed no significant differences in the other outcomes. Although patient satisfaction with DDs was inferior to that with CDs, 20% of patients preferred and used DDs (12 patients preferred CDs, and three patients opted for DDs).

CONCLUSION

Although patient satisfaction or QOL with DDs may be somewhat inferior to that with CDs, 20% of patients preferred and used DDs daily. Thus, DDs fabricated using 3D printing may have comparable practicality and efficacy to CDs.

Retrospective Comparison of Postinsertion Maintenances Between Conventional and 3D Printed Complete Dentures Fabricated in a Predoctoral Clinic

PURPOSE

A retrospective study to analyze the clinical performance of 3D printed complete dentures in edentulous patients compared with conventional complete dentures regarding postinsertion visits and patient reported outcomes.

MATERIAL AND METHODS

Electronic charts were reviewed to analyze 420 (maxilla 270, mandible 150) heat-polymerized conventional complete dentures (CCD) inserted between July 1, 2015 and June 30, 2016 and 217 (maxilla 130, mandible 86) 3D printed complete dentures (PCD) inserted between July 1, 2017 and June 30, 2018. Number of remakes, number of postinsertion adjustments, type and number of repairs, and patient reported complications were compared between two types of complete dentures. The frequency of denture repair and patient reported complications were analyzed using chi-square of independence test.

RESULTS

The frequency of pain and visible ulcer lesions in the maxilla was determined to be 46.67% with CCD and 36.15% in PCD (p = 0.047). There was no statistical significance in other items. The majority of esthetic concerns was dissatisfaction with the shape of dentures with CCD (4.67%) and they had statistically significant, less frequent, esthetic problems than PCD (11.63%) (p = 0.047).

CONCLUSIONS

Similar clinical performance was recorded between the two groups, but the overall pain and visible ulcer lesions were less in the printed complete dentures then the conventionally processed dentures. However, the esthetic aspect was better in conventionally processed complete dentures.

A Comprehensive Systematic Review In Search Of Evidence for Pragmatic Altercations in Simplified Denture

Aim:

To explore the evidence available to evaluate if simplified dentures could be as effective as the conventional complete dentures.

Materials and Methods:

A total of 1,482 articles were obtained using keywords in a Boolean search operator in the PubMed search engine, Google Scholar and Cochrane Library. Duplicates were removed and the remaining articles were subjected to a title analysis which yielded a total of 20. Further analysis of the article abstracts led to an exclusion of four articles. The remaining 16 articles were subjected to full text analysis which finally yielded a total of 11 articles.

Results:

The cumulative results of the meta-analysis for oral health-related quality of life, patient satisfaction and professional quality of denture show no significant difference ( P > .05) between conventional and simplified dentures.

Conclusion:

Based on the available evidence adjusted for the potential literature/geographic bias, we conclude that the conventional procedures in complete denture fabrication such as facebow and gothic arch tracing do not improve the quality of the denture outcome from patients’ perspective and simplified dentures are equally effective as conventional complete dentures.

Efficiency of simplified versus traditional denture fabrication methods: A systematic review and meta-analysis

STATEMENT OF PROBLEM

Conventional techniques (CTs) for complete denture fabrication involve a series of clinical and laboratory steps. A simplification of this process has been advocated, but whether simplified techniques result in acceptable treatment outcomes is unclear.

PURPOSE

The purpose of this systematic review and meta-analysis was to evaluate the efficiency of simplified denture fabrication techniques in comparison with CTs.

MATERIAL AND METHODS

The standard methodological procedures prescribed by the Cochrane Collaboration for systematic review and meta-analysis were used. An electronic search (MEDLINE through PubMed, Cochrane trial registry, and Scopus) and a manual search up to February 2020 were made to identify studies. Only randomized controlled trials involving edentulous adults requiring complete denture treatment were included.

RESULTS

Nineteen studies met the inclusion criteria. The pooled estimate of the included studies for patient satisfaction at 6 months marginally favored the simplified method of denture fabrication (standardized mean difference=0.02 [95% confidence interval {CI} -0.22 to 0.27]). The pooled estimate of the included studies for clinical time and cost of fabrication favored the simplified method (mean difference=-77.34 [95% CI -122.45 to -32.24] and mean difference=-85.89 [95% CI -170.02 to -1.77] respectively).

CONCLUSIONS

Simplified techniques were cost effective and less time consuming than the CT, with no significant difference in patient satisfaction or oral health-related quality of life. The high risk of bias and heterogeneity among studies requires that the results be considered cautiously.

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).

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.

Clinical evaluation of tissue stops on 3D-printed custom trays

This study evaluated the quality of impressions taken using three-dimensional (3D)-printed custom trays with different tissue stops to optimize the custom tray designs. Different custom trays were designed and printed based on six edentulous patients. These trays were divided into four groups based on the tissue-stop designs: 3DP trays (3D-printed trays without tissue stops), 3DPS trays (3D-printed trays with saddle-shaped tissue stops), 3DPM trays (3D-printed trays with marginal-band tissue stops) and 3DPIM trays (3D-printed trays with inner marginal-band tissue stops). Final impressions were taken using these trays, of which, the 3DP and 3DPIM trays were preborder-moulded. The finished complete dentures were used to take impressions that were set as the reference group to analyse the accuracy of the final impressions. The impressions taken using the 3DP custom trays (preborder-moulded) were used as a reference to analyse the extensions of the impressions taken using the other three custom trays. Randomized block or Friedman tests were used to evaluate each group’s statistical significance. The results revealed that the 3DPIM custom trays with the inner marginal-band tissue stop facilitated the preborder-moulding process and improved the accuracy and extension of the impression.

Masticatory performance of different impression methods for complete denture fabrication: A randomized controlled trial

OBJECTIVES

To compare the effect of conventional complete dentures fabricated using two different impression methods on masticatory performance and factors relating to masticatory performance in a randomized controlled trial.

METHODS

A crossover randomized controlled trial was performed with edentulous patients requiring maxillomandibular complete dentures. Mandibular complete dentures were fabricated using two different methods. The conventional method (C) used a custom tray border molded with an impression compound and a silicone. The simplified method (S) used a stock tray and an alginate. Participants were randomly divided into the two groups. In the C-S group, the conventional method was used first, followed by the simplified method; the order was reversed in the SC group. Adjustments were performed four times. The wash out period was 1 month. Masticatory performance as assessed by the mixing of a color-changeable chewing gum (mixing ability). Maximum occlusal force, occlusal contact area, and perceived chewing ability were assessed for each group.

RESULTS

Twenty-seven patients underwent randomization and 24 participants completed the trial. With regard to occlusal contact area, the conventional method showed significantly larger occlusal contact area than the simplified method. No significant differences were observed between the two methods regarding mixing ability, maximum occlusal force, and perceived chewing ability.

CONCLUSIONS

This study showed that complete dentures fabricated with the conventional method had a significantly larger occlusal contact area than those made using the simplified method.

CLINICAL SIGNIFICANCE

Complete dentures fabricated with the conventional method, comprising a preliminary impression using alginate in a stock tray followed by a final impression using silicone impression material in a border molded custom tray, resulted in fewer post-insertion adjustments than the simplified method, potentially contributing to earlier stability of new dentures.

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.

Final-impression techniques and materials for making complete and removable partial dentures

BACKGROUND

Edentulism is relatively common and is often treated with the provision of complete or partial removable dentures. Clinicians make final impressions of complete dentures (CD) and removable partial dentures (RPD) using different techniques and materials. Applying the correct impression technique and material, based on an individual's oral condition, improves the quality of the prosthesis, which may improve quality of life.

OBJECTIVES

To assess the effects of different final-impression techniques and materials used to make complete dentures, for retention, stability, comfort, and quality of life in completely edentulous people.To assess the effects of different final-impression techniques and materials used to make removable partial dentures, for stability, comfort, overextension, and quality of life in partially edentulous people.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 22 November 2017), the Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Register of Studies, to 22 November 2017), MEDLINE Ovid (1946 to 22 November 2017), and Embase Ovid (21 December 2015 to 22 November 2017). The US National Institutes of Health Trials Registry (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on language or publication status when searching the electronic databases, however the search of Embase was restricted by date due to the Cochrane Centralised Search Project to identify all clinical trials and add them to CENTRAL.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing different final-impression techniques and materials for treating people with complete dentures (CD) and removable partial dentures (RPD). For CD, we included trials that compared different materials or different techniques or both. In RPD for tooth-supported conditions, we included trials comparing the same material and different techniques, or different materials and the same technique. In tooth- and tissue-supported RPD, we included trials comparing the same material and different dual-impression techniques, and different materials with different dual-impression techniques.

DATA COLLECTION AND ANALYSIS

Two review authors independently, and in duplicate, screened studies for eligibility, extracted data, and assessed the risk of bias for each included trial. We expressed results as risk ratios (RR) for dichotomous outcomes, and as mean differences (MD) or standardised mean differences (SMD) for continuous outcomes, with 95% confidence intervals (CI), using the random-effects model. We constructed 'Summary of findings' tables for the main comparisons and outcomes (participant-reported oral health-related quality of life, quality of the denture, and denture border adjustments).

MAIN RESULTS

We included nine studies in this review. Eight studies involved 485 participants with CD. We assessed six of the studies to be at high risk of bias, and two to be at low risk of bias. We judged one study on RPD with 72 randomised participants to be at high risk of bias.Overall, the quality of the evidence for each comparison and outcome was either low or very low, therefore, results should be interpreted with caution, as future research is likely to change the findings.Complete denturesTwo studies compared the same material and different techniques (one study contributed data to a secondary outcome only); two studies compared the same technique and different materials; and four studies compared different materials and techniques.One study (10 participants) evaluated two stage-two step, Biofunctional Prosthetic system (BPS) using additional silicone elastomer compared to conventional methods, and found no evidence of a clear difference for oral health-related quality of life, or quality of the dentures (denture satisfaction). The study reported that BPS required fewer adjustments. We assessed the quality of the evidence as very low.One study (27 participants) compared selective pressure final-impression technique using wax versus polysulfide elastomeric (rubber) material. The study did not measure quality of life or dentures, and found no evidence of a clear difference between interventions in the need for adjustments (RR 0.81, 95% CI 0.38 to 1.70). We assessed the quality of the evidence as very low.One study compared two stage-two step final impression with alginate versus silicone elastomer. Oral health-related quality of life measured by the OHIP-EDENT seemed to be better with silicone (MD 7.20, 95% CI 2.71 to 11.69; 144 participants). The study found no clear differences in participant-reported quality of the denture (comfort) after a two-week 'confirmation' period, but reported that silicone was better for stability and chewing efficiency. We assessed the quality of the evidence as low.Three studies compared single-stage impressions with alginate versus two stage-two step with elastomer (silicone, polysulfide, or polyether) impressions. There was no evidence of a clear difference in the OHIP-EDENT at one month (MD 0.05, 95% CI -2.37 to 2.47; two studies, 98 participants). There was no evidence of a clear difference in participant-rated general satisfaction with dentures at six months (MD 0.00, 95% CI -8.23 to 8.23; one study, 105 participants). We assessed the quality of the evidence as very low.One study compared single-stage alginate versus two stage-two step using zinc-oxide eugenol, and found no evidence of a clear difference in OHIP-EDENT (MD 0.50, 95% CI -2.67 to 3.67; 39 participants), or general satisfaction (RR 3.15, 95% CI 0.14 to 72.88; 39 participants) at six months. We assessed the quality of the evidence as very low.Removable partial denturesOne study randomised 72 participants and compared altered-cast technique versus one-piece cast technique. The study did not measure quality of life, but reported that most participants were satisfied with the dentures and there was no evidence of any clear difference between groups for general satisfaction at one-year follow-up (low-quality evidence). There was no evidence of a clear difference in number of intaglio adjustments at one year (RR 1.43, 95% CI 0.61 to 3.34) (very low-quality evidence).

AUTHORS' CONCLUSIONS

We conclude that there is no clear evidence that one technique or material has a substantial advantage over another for making complete dentures and removable partial dentures. Available evidence for the relative benefits of different denture fabrication techniques and final-impression materials is limited and is of low or very low quality. More high-quality RCTs are required.

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.

Clinical evaluation of final impressions from three-dimensional printed custom trays

This study aimed to evaluate the quality of the final impressions taken by three-dimensional printed custom trays for edentulous patients. Custom trays were designed with or without saddle-shaped tissue stops and fabricated by three-dimensional printing techniques. Manually made trays with photocurable materials were produced as controls. Both 3D printed custom trays and manually made ones were used to take impressions from edentulous patients. After 3D scanning of the final impression, the impression materials were removed, thus the underneath tray surfaces were able to be scanned, allowing the thickness of the impression materials to be measured. Final impressions obtained by pre-border-molded 3D printed trays were scanned as references, to which the flange extension deviations and morphology deviations of the impressions taken by both 3D printed trays and manually made ones were calculated. The results showed that (1) impressions from 3D printed custom trays had better thickness distribution than that of manually made ones; (2) impression morphology deviations in non-marginal area were neither statistic different between 3D printed trays and manually made trays, nor between trays with and without tissue stops; and (3) final impressions taken by custom trays without pre-border-molding were tended to have insufficient flange extensions.

Cost-effectiveness analysis of two impression methods for the fabrication of mandibular complete dentures

OBJECTIVES

To compare the cost and to evaluate cost-effectiveness of fabricating mandibular complete dentures (CDs) using two different impression methods.

METHODS

A crossover randomized controlled trial including 27 edentulous participants was performed. Mandibular CDs were fabricated using two different impression methods, as follows: (i) conventional method using a custom tray border moulded with impression compound and silicone and (ii) simplified method using a stock tray and alginate. Cost analysis was performed from a clinical practitioner's perspective. The total cost included labor cost, which was calculated using the time spent by dentists and technicians in fabricating CDs and their hourly wages, and the material costs, which were calculated using purchase prices. To evaluate cost-effectiveness, we used general patient satisfaction as an indicator of effectiveness and calculated the incremental cost effectiveness ratio (ICER). ICER represents the cost per one unit of effectiveness.

RESULTS

The trial was completed by 24 participants. The total cost was 43,904 Japanese Yen (JPY) (330.91 EUR / 395.78 USD) for the conventional method and 39,792 JPY (299.93 EUR / 358.70 USD) for the simplified method, and this difference was statistically significant (p<0.001). The ICER showed a cost of 633 JPY (4.77 EUR / 5.70 USD) for every one point change in general patient satisfaction.

CONCLUSIONS

The results indicated that the total cost of the conventional method was significantly higher than that of the simplified method (p<0.001).

CLINICAL SIGNIFICANCE

The conventional impression method for fabricating mandibular CDs, which took additional 633 JPY (4.77 EUR / 5.70 USD) for improvement of general satisfaction, is supposed to be clinically meaningful¹.

Annual review of selected scientific literature: Report of the committee on scientific investigation of the American Academy of Restorative Dentistry

STATEMENT OF PROBLEM

It is clear the contemporary dentist is confronted with a blizzard of information regarding materials and techniques from journal articles, advertisements, newsletters, the internet, and continuing education events. While some of that information is sound and helpful, much of it is misleading at best.

PURPOSE

This review identifies and discusses the most important scientific findings regarding outcomes of dental treatment to assist the practitioner in making evidence-based choices. This review was conducted to assist the busy dentist in keeping abreast of the latest scientific information regarding the clinical practice of dentistry.

MATERIAL AND METHODS

Each of the authors, who are considered experts in their disciplines, was asked to peruse the scientific literature published in 2015 in their discipline and review the articles for important information that may have an impact on treatment decisions. Comments on experimental methodology, statistical evaluation, and overall validity of the conclusions are included in many of the reviews.

RESULTS

The reviews are not meant to stand alone but are intended to inform the interested reader about what has been discovered in the past year. The readers are then invited to go to the source if they wish more detail.

CONCLUSIONS

Analysis of the scientific literature published in 2015 is divided into 7 sections, dental materials, periodontics, prosthodontics, occlusion and temporomandibular disorders, sleep-disordered breathing, cariology, and implant dentistry.

Influence of one- or two-stage methods for polymerizing complete dentures on adaptation and teeth movements

Abstract Introduction The quality of complete dentures might be influenced by the method of confection. Objective To evaluate the influence of two different methods of processing muco-supported complete dentures on their adaptation and teeth movements. Material and method Denture confection was assigned in two groups (n=10) for upper and lower arches according to polymerization method: 1) conventional one-stage - a wax trial base was made, teeth were arranged and polymerized; 2) two-stage method - the base was waxed and first polymerized. With the denture base polymerized, the teeth were arranged and then, performed the final polymerization. Teeth movements were evaluated in the distances between incisive (I-I), pre-molars (P-P), molars (M-M), left incisor to left molar (LI-LM) and right incisor to right molar (RI-RM). For the adaptation analysis, dentures were cut in three different positions: (A) distal face of canines, (B) mesial face of the first molars, and (C) distal face of second molars. Result Denture bases have shown a significant better adaptation when polymerized in the one-stage procedure for both the upper (p=0.000) and the lower (p=0.000) arches, with region A presenting significant better adaptation than region C. In the upper arch, significant reduction in the distance between I-I was observed in the one-stage technique, while the two-stage technique promoted significant reduction in the RI-RM distance. In the lower arch, one-stage technique promoted significant reduction in the distance for RI-RM and two-stage promoted significant reduction in the LI-LM distance. Conclusion Conventional one-stage method presented the better results for denture adaptation. Both fabrication methods presented some alteration in teeth movements.

Application of FDM three-dimensional printing technology in the digital manufacture of custom edentulous mandible trays

The objective was to establish and evaluate a method for manufacture of custom trays for edentulous jaws using computer aided design and fused deposition modeling (FDM) technologies. A digital method for design the custom trays for edentulous jaws was established. The tissue surface data of ten standard mandibular edentulous plaster models, which was used to design the digital custom tray in a reverse engineering software, were obtained using a 3D scanner. The designed tray was printed by a 3D FDM printing device. Another ten hand-made custom trays were produced as control. The 3-dimentional surface data of models and custom trays was scanned to evaluate the accuracy of reserved impression space, while the difference between digitally made trays and hand-made trays were analyzed. The digitally made custom trays achieved a good matching with the mandibular model, showing higher accuracy than the hand-made ones. There was no significant difference of the reserved space between different models and its matched digitally made trays. With 3D scanning, CAD and FDM technology, an efficient method of custom tray production was established, which achieved a high reproducibility and accuracy.