A Randomised Controlled Trial of Postoperative Sensitivity after Class II Restoration with Bulk-Fill vs Conventional Composites

INTRODUCTION

Bulk-fill composites may simplify posterior restorations, saving time and reducing technical complexity. Post-operative sensitivity is a risk of posterior composites; bulk-fill composites could mitigate this. This single centre, double-blinded, parallel groups randomised controlled trial compared postoperative sensitivity following restoration of class II carious lesions with bulk-fill or conventional, layered composite.

NULL HYPOTHESIS

there will be no difference in post-operative sensitivity between the two materials.

METHODS

Participants requiring class II restoration of posterior teeth were randomised to bulk-fill (FU) (Coltene Fill-UpTM) or conventional, layered (BE) (Coltene Brilliant Everglow) composite. Allocation was concealed during cavity preparation. Only the operating dentist knew allocation. The outcome was 24 h post-operative sensitivity.

RESULTS

41 patients were randomised (20/group). Two patients from FU group were excluded from analysis (factors unrelated to intervention). There was no difference in postoperative sensitivity at 24 h nor any time point. Only participant age and baseline sensitivity scores significantly impacted post-operative sensitivity. One restoration debonded in FU group at 10 days, with no other adverse effects. No difference in time taken to place restorations was seen.

CONCLUSIONS

Within the study's limitations, post-operative sensitivity after class II posterior restorations was no different in bulk-fill restorations compared with conventional, incrementally cured composite.

Current challenges for 3D printing complete dentures: experiences from a multi-centre clinical trial

Aims To develop an optimal clinical and laboratory protocol for the fabrication of 3D printing dentures.Design A prospective feasibility study across three UK dental schools.Material and methods Each patient received one conventional and one 3D-printed denture. Both dentures were constructed using the same impression, jaw registration and wax trial denture. Variables investigated included methods of digitisation of the impression and optional use of a 3D-printed baseplate for jaw registration.Results Clinicians strongly preferred 3D-printed baseplates. Patients felt that conventional and printed dentures were similar in retention and stability. More patients favoured conventional dentures over 3D-printed dentures in terms of comfort.Discussion It is feasible to combine conventional clinical work with digital techniques to produce 3D-printed dentures. 3D-printed baseplates offer a cost-effective alternative to conventional bases at the jaw registration stage. Challenges were faced in tooth positioning and managing occlusion, particularly where roots required adjustment.Conclusion 3D printing is suitable for producing baseplates for jaw registration blocks and wax trial insertions. It is feasible to produce 3D-printed dentures using conventional clinical techniques for impressions, jaw registration and wax trial insertion. The workflow used in this study for 3D-printed dentures is not superior to conventional dentures. Further work is required.

A Comparative study on the Effectiveness of Augmented Reality on Denture Tooth Selection

One of the most difficult aspects of providing removable dentures, for both the patient and the dentist, is the tooth selection process. The aim of this study was to assess the effectiveness of augmented reality (AR) on patient experience of the tooth selection process.

MATERIALS AND METHODS

3D scanning of upper anterior teeth of various shapes and sizes allowed for the creation of a virtual library that were subsequently used to programme an AR software application, 'ToothPick'. Seventeen participants were recruited to a comparative study at Leeds Dental Institute, over two clinical appointments, to trial the app and complete a 10-question survey to assess the efficacy of AR simulation. The sample size response generated outcome variables for 'perceived usefulness' and 'perceived ease of use' from the perspectives of the patient, dentist and technician.

RESULTS

By the second appointment, 86% of participants preferred the app over the conventional methods for selection of denture teeth due to increased ease of use and accuracy that AR simulation had in replicating the wax try-in.

CONCLUSION

The sample population favoured the adoption of AR technology to select denture teeth from the perspective of both the patient and the clinician.

Deformation and retentive force following in vitro cyclic fatigue of cobalt-chrome and aryl ketone polymer (AKP) clasps

OBJECTIVE

To compare the retention force of individual clasps made from cobalt chromium (CoCr) or new aryl ketone polymer (AKP) material, Ultaire™ AKP, following prolonged fatigue testing along ideal and non-ideal paths of removal and to assess 3D deformation of the active and passive clasp tips.

METHODS

CoCr and AKP clasps were manufactured in their standard, respective processes, digitally scanned prior to testing, then cycled 15,000 times over an e.max analogue crown in artificial saliva. Retentive load was measured in situ, as a function of cycles. Clasps were rescanned to assess deformation and along with their antagonists subjected to SEM to assess localised wear.

RESULTS

Distortion of the CoCr clasps was consistently larger than Ultaire™ AKP clasps, irrespective of removal path. CoCr clasps had significantly higher retentive forces than AKP clasps, for both removal paths. Ultaire™ AKP clasps showed a lower but relatively constant retentive force. The non-ideal path of removal affected retentive forces for both clasp materials. SEM showed localised removal of glaze for e.max crowns used with CoCr clasps.

SIGNIFICANCE

Ultaire™ AKP clasps showed significantly less permanent deformation and lower retentive force than CoCr clasps. Unlike CoCr, the Ultaire™ AKP clasps did not work harden, nor had as large a reduction in retentive force and accompanying permanent deformation; the retentive force for the Ultaire™ AKP clasps was consistent over 15,000 cycles of fatigue mimicking prolonged clinical use. The AKP material was more robust; showing minimal deformation even in non-ideal paths of removal, as many patients would routinely use.

A Systematic Review and Meta-Analysis of Baseline Ohip-Edent Scores

BACKGROUND

OHIP-EDENT is widely used in the literature to assess Oral-Health-Related-Quality-of-Life (OHRQoL) for edentulous patients. However the normal variance and mean of the baseline OHIP scores has not been reported. It would facilitate critical appraisal of studies if we had knowledge of the normal variation and mean of baseline OHIP-EDENT scores. An established figure for baseline OHIP-EDENT, obtained from a meta-analysis, would simplify comparisons of studies and quantify variations in initial OHRQoL of the trial participants.

OBJECTIVES

The aim of this study is to quantify a normal baseline value for pre-operative OHIP-EDENT scores by a systematic review and meta-analysis of the available literature.

METHODS

A systematic literature review was carried. 83 papers were identified that included OHIP-EDENT values. After screening and eligibility assessment, 7 papers were selected and included in the meta-analysis.

RESULTS

A meta-analysis for the 7 papers by a random-effect model yielded a mean baseline OHIP-EDENT score of 28.63 with a 95% Confidence intervals from 21.93 to 35.34.

CONCLUSION

A pre-operative baseline OHIP-EDENT has been established by meta-analysis of published papers. This will facilitate the comparison of the initial OHRQoL of one study population to that found elsewhere in the published literature.

Randomized Controlled Trial of Postoperative Sensitivity with Warm and Room Temperature Composite

Physical properties of composite improve when it is preheated prior to polymerization. However, postoperative sensitivity may be considered a potential complication. A review of the literature revealed no reported randomized controlled trials (RCTs) of postoperative sensitivity when using preheated composite resin. The objective of the study was to determine if preheating composite leads to changes in postoperative sensitivity in a parallel RCT. In total, 120 eligible, consenting adults were recruited in private dental practice and randomized into 2 groups of 60 patients. One group had room temperature composite restorations placed and the second had composite preheated to 39°C. The primary outcome was sensitivity after 24 h by the visual analog scale (VAS), recorded blind by patients. Secondary outcomes were VAS scores recorded over a month. Blind statistical analysis used the Mann-Whitney U test to compare the 24-h VAS score between groups and repeated-measures analysis of variance to assess the change over time. Potential confounders were tested using regression models. A total of 115 patients completed the trial: 57 in the heated composite group and 58 in the room temperature group. Analysis of 24-h VAS scores found no statistically significant difference between the 2 groups ( P = 0.162). Examining the potential confounders confirmed the nonsignificant difference between heated and room temperature groups on the 24-h VAS score, after controlling teeth type and preoperative pulp test (effect size = 0.173, P = 0.317). Analysis of the secondary outcomes found significant changes (within-subject effect) in VAS scores over the review period ( F statistic = 4.7, P = 0.002) but not a significant (between-subject effect) difference between heated and room temperature groups over time (effect size = 0.102, P = 0.197). There was a significant correlation between preoperative VAS score and postoperative VAS score ( P < 0.001). For the restorations in this study, there was no detectable difference in postoperative VAS score between preheated and room temperature composite. Postoperative sensitivity decreased throughout the first month. Postoperative sensitivity was correlated to preoperative sensitivity (ISRCTN 76727312). Knowledge Transfer Statement: The results of this study can be used by clinicians when considering the advantages and disadvantages of preheated composite. The study found no evidence of any change in postoperative sensitivity when using preheated composite. Since preheated composite has superior physical properties, its use for routine care can be considered good practice.

A Randomised Controlled Study Comparing the Anterior Mandibular Labio-Lingual Neutral Zone Position in Edentulous Subjects With and Without Their Maxillary Denture In-Situ

Opinion is divided as to whether the neutral zone impression to determine the labio-lingual position of mandibular complete dentures requires the maxillary denture to remain in-situ or not. Two such neutral zone impressions were recorded for each of the 12 participants of this randomised controlled study. The presence of the maxillary denture made no statistically significant mean difference in labio-lingual position of the mandibular neutralzone. Within the confines of this research protocol there was no evidence that the shift in the labio-linguial position of the anterior mandibular neutral zone was consistently affected by the presence of a maxillary appliance.

Dentures for Randomised Controlled Trials

Making complete dentures for dental research is difficult. The difficulty is not in the construction of dentures, but making sure the clinician is blind to the randomizations, and avoiding confounding variables. For research purposes it is essential that two sets of dentures are similar in every way, apart from the area to be investigated. A previous article showed how to duplicate a lower denture when it was articulated against a single upper denture. This paper describes the additional duplication of upper dentures. These additional problems presented the clinical and technical teams at the Leeds Dental Institute some challenges.

A randomised controlled trial of complete denture impression materials

Objectives

There is continuing demand for non-implant prosthodontic treatment and yet there is a paucity of high quality Randomised Controlled Trial (RCT) evidence for best practice. The aim of this research was to provide evidence for best practice in prosthodontic impressions by comparing two impression materials in a double-blind, randomised, crossover, controlled, clinical trial.

Methods

Eighty-five patients were recruited, using published eligibility criteria, to the trial at Leeds Dental Institute, UK. Each patient received two sets of dentures; made using either alginate or silicone impressions. Randomisations determined the order of assessment and order of impressions. The primary outcome was patient blinded preference for unadjusted dentures. Secondary outcomes were patient preference for the adjusted dentures, rating of comfort, stability and chewing efficiency, experience of each impression, and an OHIP-EDENT questionnaire.

Results

Seventy-eight (91.8%) patients completed the primary assessment. 53(67.9%) patients preferred dentures made from silicone impressions while 14(17.9%) preferred alginate impressions. 4(5.1%) patients found both dentures equally satisfactory and 7 (9.0%) found both equally unsatisfactory. There was a 50% difference in preference rates (in favour of silicone) (95%CI 32.7–67.3%, p < 0.0001).

Conclusion

There is significant evidence that dentures made from silicone impressions were preferred by patients.

Clinical significance

Given the strength of the clinical findings within this paper, dentists should consider choosing silicone rather than alginate as their material of choice for secondary impressions for complete dentures.

Trial Registration: ISRCTN 01528038.



This article forms part of a project for which the author (TPH) won the Senior Clinical Unilever Hatton Award of the International Assocation for Dental Research, Capetown, South Africa, June 2014.

IMPROVDENT: improving dentures for patient benefit. A crossover randomised clinical trial comparing impression materials for complete dentures

Background

According to the UK Adult Dental Health Survey (2009) 15% of adults aged 65–74, 30% aged 75–84 and 47% aged >85 years are edentulous and require complete dentures. Patients’ quality of life and nutrition status are affected by poor dentures. The quality of the dental impression is the most important issue for improving the fit and comfort of new dentures. There is paucity of RCT evidence for which impression material is best for complete dentures construction. This study aims to compare two impression materials for effectiveness and cost effectiveness.

Methods/Design

IMPROVDENT is a double-blind crossover trial comparing the use of alginate and silicone, two commonly used denture impression materials, in terms of patient preference and cost-effectiveness. Eighty five edentulous patients will be recruited and provided with two sets of dentures, similar in all aspects except for the impression material used (alginate or silicone). Patients will try both sets of dentures for a two-week period, unadjusted, to become accustomed to the feel of the new dentures (habituation period). Patients will then wear each set of dentures for a period of 8 weeks (in random order) during which time the dentures will be adjusted for optimum comfort. Finally, patients will be given both sets of dentures for a further two weeks to wear whichever denture they prefer (confirmation period).

Patients will be asked about quality of life and to rate dentures on function and comfort at the end of each trial period and asked which set they prefer at the end of the habituation period (unadjusted denture preference) and confirmation period (adjusted denture preference). A health economic evaluation will estimate incremental cost-effectiveness ratios of producing dentures from the two materials. A qualitative study will investigate the impact of dentures on behaviour and quality of life.

Funding: IMPROVDENT is funded by NIHR RfPB (PB-PG-0408-16300).

Discussion

This trial aims to provide evidence on the costs and quality of dentures cast from two different commonly used impression materials; the intention is to significantly impact on the quality of denture production within NHS dentistry.

Trial Registration

ISRCTN Register: ISRCTN01528038

UKCRN Portfolio ID: 8305

Providing support for the pontic of natural tooth adhesive bridges: a clinical report

Resin bonded bridges have become established as a treatment option for replacing missing teeth. Their development can be traced to the work of Rochette who used a macro mechanically bonded metal framework to stabilize mobile teeth. Adaptations of Rochette's concept, using natural teeth as pontics, have been presented. The use of a natural tooth has aesthetic and psychological advantages for the patient. The high failure rate of natural tooth pontics may be explained by a lack of support for the tooth on the metal framework. A clinical report is presented to illustrate a previously unreported technique to improve pontic support.

The effect of seating velocity on pressure within impressions

STATEMENT OF PROBLEM

Oral mucosa can distort under impressions. To reduce or control mucosal distortion, modern impression techniques aim to reduce or control the impression pressure. If changing seating velocity significantly changes pressure, then this effect should be considered for clinical impressions of mucosa.

PURPOSE

The purpose of this study was to investigate the relationship between seating velocity and pressure generation during simulated impressions.

MATERIAL AND METHODS

Vinyl polysiloxane impression material (Express) was placed between 2 approximating discs in a universal testing machine. The velocity at which the discs approximated was varied. The 7 selected seating velocities were 0.75 mm/s, 1 mm/s, 1.25 mm/s, 1.5 mm/s, 2 mm/s, 2.5 mm/s, and 3 mm/s. The pressure generated at the center of the disk was recorded. Five separate recordings were made for each velocity. One-way ANOVA and post hoc tests (Tukey B and Dunnett T3) (alpha=.05) were used to evaluate peak pressure data at each velocity.

RESULTS

The mean (SD) of the recorded pressures for each velocity were 239 (6.67) KPa, 273 (14.89) KPa, 347 (11.97) KPa, 425 (19.73) KPa, 487 (17.84) KPa, 547 (21.25) KPa, and 624 (32.60) KPa, respectively. As the velocity increased, there was a significant (P<.001) concurrent increase in peak pressure.

CONCLUSIONS

In this in vitro experiment, changing the velocity of seating had a significant effect on the peak pressure produced during simulated impressions.

Case report: differential pressure impressions for complete dentures

A method of producing a differential pressure, secondary impression of a lower arch with a sharp bony ridge is described. The use of this technique allows the clinician to dictate where the load is to be borne by the mucosa.

Survey of prosthodontic impression procedures for complete dentures in general dental practice in the United Kingdom

STATEMENT OF PROBLEM

Anecdotal evidence suggests impression techniques used in general dental practice may vary from those taught at dental schools. There is little published information on this topic.

PURPOSE

This study identifies the materials and methods used by general dental practitioners for recording impressions for the provision of replacement of complete dentures.

METHODS

A total of 905 questionnaires were sent to general dental practitioners in the Greater Manchester area to identify current clinical practices.

RESULTS

The results revealed that 88% of respondents use only irreversible hydrocolloid for primary impressions. If multiple responses are included, 99% of respondents mentioned irreversible hydrocolloids as an option for primary impressions. In response to the same question for secondary impressions, 94% of respondents mentioned irreversible hydrocolloids as an option. Other material mentioned as an option for secondary impressions included zinc oxide-eugenol (29%) and polyvinyl siloxane (13%). With regard to special trays, 75% of respondents routinely used laboratory constructed special trays to take definitive impressions. Questions on the requisite spacing, perforation, handle design of special trays, and on disinfection showed a diversity of opinion among practitioners.

CONCLUSIONS

Although this survey reflected a diverse range of clinical preferences, it is clear that irreversible hydrocolloid dominates the impression market for complete dentures. The use of special trays is normal practice for complete dentures in general dental practice in the United Kingdom.

Gender aesthetics in the natural dentition

This paper questions whether the size, position and angulation of upper anterior teeth 'reflect' the gender of a patient. Forty-six casts of natural teeth were given to 11 experts. The experts were asked to assess the gender of the patients. Overall the intra-observer agreement was fair (kappa = 0.33). Inter-observer agreement was fair (kappa = 0.23). On average 55% of casts taken from men were classified as 'male' and 55% of the casts taken from women were classified as 'female'. It is concluded, on the basis of this study, experts can not distinguish gender by the visual assessment of upper anterior teeth on casts alone.

Case report: the high proximal survey line

This case report demonstrates a method of adding composite to a tooth to move a high survey line closer to the gingival margin. The purpose of this modification is to facilitate clasping.

Extraction forceps for small hands

This paper discusses the problems encountered by small handed dentists when extracting teeth using standard forceps. An alteration in the design of standard upper forceps is proposed which will be advantageous to small handed dentists. The new design is 'open bladed', that is, when the handles are closed the blades are manufactured to be 5 mm apart.

A reattachment technique for fractured incisor tooth fragments: a case history and discussion of alternative techniques

This paper describes the case history of a patient for whom two fractured central incisor fragments were reattached using an acid etch technique. The case demonstrates a method, which has not been reported previously, using pins to reinforce the attachment. Finally the case shows the failure of the reattachment on one central incisor and subsequent successful treatment by the use of a veneer crown.

T-cell prolymphocytic leukemia with helper-cell phenotype and a review of the literature

The majority of published cases of prolymphocytic leukemia (PLL) have been of B-cell origin. Nineteen cases of PLL of T-cell type have been described, as has a single case of PLL having a surface phenotype with features of both B-cells and T-cells. This report presents a review of these cases and comparison with one case of T-cell PLL. By using specific monoclonal antibody technique, this case was subcategorized into helper-cell phenotype: E-rosette(+), SIG(-), Anti-T(+), Anti-B(-), Anti-monocyte(-), OKT3(+), OKT4(+), OKT6(-), OKT8(-), Ia(+), and Tdt(-). Cytochemical studies showed paranuclear acid phosphatase granules. Postmortem examination revealed a predominant T-cell zone infiltration by the leukemic cells in the spleen and lymph nodes, with involvement of multiple organs. The application of the monoclonal antibody technique, which can be standardized among different laboratories to subclassify lymphoproliferative disorders into functional subtypes, should lead to a better understanding and more effective treatment of this disease.