Can patients detect peri‑implant mucosal inflammation? Results from a multicentre randomized trial

PURPOSE

The objective of this study was to compare patient-reported outcomes (PROs) of peri‑implant soft tissue inflammation and aesthetics around single-tooth implants in the anterior maxillary region with three different implant-abutment interface designs.

METHODS

Participants were randomized to one of three different types of implant-abutment interface designs [Conical (CI), flat-to-flat (FI), and Platform Switched (PS)]. Implants and provisional crowns with prefabricated titanium abutments were placed 5 months following extraction and/or ridge augmentation. Permanent ceramic crowns with zirconia abutments were placed after 12 weeks. To assess PROs, appearance and inflammation questionnaires were completed from provisional crown placement to the 3-year follow-up.

RESULTS

Tooth appearance at the 3-year follow-up revealed a difference amongst CI, FI and PS implants (p=0.049; Kruskal-Wallis test). PS was rated better than FI (p=0.047) at 1 year for appearance of soft-tissue and satisfaction with colour. There were no differences for self-consciousness, smile and pain/discomfort while eating/hard food items.

CONCLUSIONS

Although participants tended to rate the health of mucosa around PS implants as slighty better than the other two implant systems, the differences were minimal and inconsistent. Thus, patient satisfaction in terms self-perceived gingival health and esthetics was high for all 3 systems tested, suggesting that patients are unable to detect mucosal inflammation.

CLINICAL SIGNIFICANCE

Patients find it difficult to perceive mucosal inflammation; hence, it is recommended that patients attend implant follow-up visits, even if they do not perceive inflammation. The study suggests that there is a relationship between the PROs and the clinical outcomes of tested implants.

A 5-Year Esthetic RCT Assessment of Anterior Maxillary Single-Tooth Implants with Different Abutment Interfaces

PURPOSE

This study sought to define the tissue responses at different implant-abutment interfaces by studying bone and peri-implant mucosal changes using a 5-year prospective randomized clinical trial design study. The conus interface was compared with the flat-to-flat interface and platform-switched implant-abutment systems.

MATERIALS AND METHODS

One hundred forty-one subjects were recruited and randomized to the three treatment groups according to defined inclusion and exclusion criteria. Following implant placement and immediate provisionalization in healed alveolar ridges, clinical, photographic, and radiographic parameters were measured at 6 months and annually for 5 years. The calculated changes in marginal bone levels, peri-implant mucosal zenith location, papillae lengths, and peri-implant Plaque Index and bleeding on probing were statistically compared.

RESULTS

Forty-eight conus interface implants, 49 flat-to-flat interface implants, and 44 platform-switched implants were placed in 141 subjects. Six platform-switched interface and eight flatto- flat interface implants failed, most of them within 3 months. After 5 years, 33 conical interface, 28 flat-to-flat interface, and 27 platform-switched interface implants remained for evaluation. Calculation of marginal bone level change showed a mean marginal bone loss of -0.16 ± 0.45 (-1.55 to 0.65), -0.92 ± 0.70 (-2.90 to 0.20), and -0.81 ± 1.06 (-3.35 to 1.35) mm for conical interface, flat-to-flat interface, and platform-switched interface implants, respectively (P < .0005). The peri-implant mucosal zenith changes were minimal for all three interface designs (0.10 mm and +0.08 mm, P > .60). Only 16% to 19% of the surfaces had presence of bleeding on probing, with no significant differences (P > .81) between groups. Interproximal tissue changes were positive and similar among the implant interface designs.

CONCLUSION

Over 5 years, the immediate provisionalization protocol resulted in stable peri-implant mucosal responses for all three interfaces. Compared with the flat-to-flat and platform-switched interfaces, the conical interface implants demonstrated significantly less early marginal bone loss. The relationship of marginal bone responses and mucosal responses requires further experimental consideration.

Development of a Checklist to Prevent Reconstructive Errors Made By Undergraduate Dental Students

PURPOSE

To design a checklist in order to reduce the frequency of reconstructive preventable errors (PE) performed by undergraduate dental students at McGill University.

MATERIALS AND METHODS

The most common PE occurring at a university dental clinic were identified by three reviewers analyzing the refunded cases, and used to create a preliminary checklist. This checklist was then validated by a panel of dental educators to produce a finalized 20-item checklist. The 20-question checklist was then submitted to students in a cross-sectional survey-based study to evaluate its relevance to undergraduate clinical education needs.

RESULTS

As many as 81% of students reported to have forgotten at least one item of the checklist during care of their last patient, and the most forgotten checklist items corresponded to the pretreatment stage. The students also reported that 17 of the 20 items in the checklist were relevant to a considerable extent or highly relevant.

CONCLUSION

Common PE identified in the undergraduate clinic could be used to create a checklist of relevant items designed to reduce errors made by students and practitioners performing prosthodontic and reconstructive treatments. However, further studies are required to evaluate the implementation and efficiency of the checklist.

Impact of immediately loaded implant-supported maxillary full-arch dental prostheses: a systematic review

OBJECTIVE

The immediate loading of implant-assisted fixed prostheses in edentulous maxillae may achieve favorable success rates with reduced treatment time. An evidence summary of clinical trials is key to recommend loading protocols in these cases.

OBJECTIVES

To compare immediately loaded, fully implant-supported complete dentures to early and conventional/delayed loading in the edentulous maxillae of adult patients by a systematic review of controlled clinical trials (CCT).

METHODOLOGY

CCTs reports were identified up to January 17, 2019 from Cochrane Oral Health Group's Trial register, Cochrane Central Register of controlled trials (CENTRAL), MEDLINE (Ovid), BIOSIS, EMBASE, CINAHL, Web of Science, and DARE. Two independent reviewers screened titles/abstracts and confirmed inclusion using full texts. Data were extracted and quality assessed (Cochrane Risk of Bias tool) independently and in duplicate. Study heterogeneity prevented pooling by meta-analysis.

RESULTS

Out of 1,052 candidate studies, four CCTs were included. Two trials had patient satisfaction as an outcome: (1) A randomized trial compared immediately and early loaded fixed dentures and found more satisfaction with the first after 12 months; (2) A non-randomized study found better satisfaction with immediate fixed dentures compared to conventional loading after 3 months (no more at 12 months). Regarding implant success and prosthetic complications, three trials did not report significant differences comparing immediate loading to other protocols.

CONCLUSIONS

This review found weak evidence of differences between immediate load and other loading regimens, regarding patient satisfaction and maintenance events/adversities. The potential of immediate loading for favorable results in edentulous maxillae reinforces the need for well-designed RCTs, for solid clinical guidelines. Registration number CRD42018071316 (PROSPERO database).

Single-implant overdentures retained by the Novaloc attachment system: study protocol for a mixed-methods randomized cross-over trial

BACKGROUND

Overdentures retained by a single implant in the midline have arisen as a minimal implant treatment for edentulous mandibles. The success of this treatment depends on the performance of a single stud attachment that is susceptible to wear-related retention loss. Recently developed biomaterials used in attachments may result in better performance of the overdentures, offering minimal retention loss and greater patient satisfaction. These biomaterials include resistant polymeric matrixes and amorphous diamond-like carbon applied on metallic components. The objective of this explanatory mixed-methods study is to compare Novaloc, a novel attachment system with such characteristics, to a traditional alternative for single implants in the mandible of edentate elderly patients.

METHODS/DESIGN

We will carry out a randomized cross-over clinical trial comparing Novaloc attachments to Locators for single-implant mandibular overdentures in edentate elderly individuals. Participants will be followed for three months with each attachment type; patient-based, clinical, and economic outcomes will be gathered. A sample of 26 participants is estimated to be required to detect clinically relevant differences in terms of the primary outcome (patient ratings of general satisfaction). Participants will choose which attachment they wish to keep, then be interviewed about their experiences and preferences with a single implant prosthesis and with the two attachments. Data from the quantitative and qualitative assessments will be integrated through a mixed-methods explanatory strategy. A last quantitative assessment will take place after 12 months with the preferred attachment; this latter assessment will enable measurement of the attachments' long-term wear and maintenance requirements.

DISCUSSION

Our results will lead to evidence-based recommendations regarding these systems, guiding providers and patients when making decisions on which attachment systems and implant numbers will be most appropriate for individual cases. The recommendation of a specific attachment for elderly edentulous patients may combine positive outcomes from patient perspectives with low cost, good maintenance, and minimal invasiveness.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03126942 . Registered on 13 April 2017.

Lay preferences for dentogingival esthetic parameters: A systematic review

STATEMENT OF PROBLEM

An objective definition of the characteristics that render a smile esthetically acceptable in the eye of laypeople is lacking.

PURPOSE

The purpose of this systematic review was to identify, appraise, and synthesize the available evidence on the opinion of laypeople regarding the dentogingival characteristics that render a smile esthetically acceptable. The evidence was collected by surveying with standardized digitally modified smile images.

MATERIAL AND METHODS

Four databases were used to search English language studies published between January 1996 and December 2015. This was complemented by a manual search of 8 dental journals. Following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, 2 independent reviewers extracted the relevant characteristics of lay evaluators, the images evaluated, and the outcomes measure. Included studies were assessed in agreement with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement. Outcomes were treated as a continuous variable, and when more than 1 article provided information on a parameter, the weighted arithmetic mean was calculated.

RESULTS

After 8851 articles were screened, 20 studies were included. Those studies addressed 20 different dentogingival esthetic parameters. The total number of participants interviewed was 3107. According to the Olmos classification, 6 studies had a high level of quality, and 14 studies had a moderate level of quality. The 2 reviewers agreed on all the quality assessments. In the articles reviewed, central incisors clearly played a key role in smile esthetics. Almost all dental, gingival, and occlusal parameters are related to the proportion, shape, and position of central incisors and their relation to the adjacent dental structures.

CONCLUSIONS

The present review provides the estimated thresholds of tolerability and ideal values of smile parameters determined by laypeople. This may guide clinicians in evidence-based diagnosis and the planning of dental esthetic treatments.

Wear of matrix overdenture attachments after one to eight years of clinical use

STATEMENT OF PROBLEM

Matrices of unsplinted attachment systems are generally reported to be the weak component of implant overdentures, often requiring frequent maintenance. Clinical wear results in reduced retention of the prosthesis, requiring activation or renewal of the matrix to restore the initial level of retention.

PURPOSE

The purpose of this retrospective study was to measure the wear of the matrix of a ball attachment after various periods of clinical wear.

MATERIAL AND METHODS

Seventy specimens of 3 groups of matrices of ball attachments that had been in use for mean periods of 12.3 months (1Y group, n=26), 39.0 months (3Y group, n=28) and 95.6 months (8Y group, n=16) were retrieved from 35 patients (2 specimens per patient) and measured on a coordinate measuring machine equipped with a touch trigger probe. Ten unused matrices were used as controls (CTRL group). The external and internal matrix diameters and deviations from circularity were measured. For the various time periods, the decreases in matrix thickness were calculated and compared with controls. Kruskal-Wallis 1-way ANOVA by ranks, followed by the Mann-Whitney post hoc tests, were conducted to test for differences in median values among groups (α =.05).

RESULTS

For the internal upper diameter of the matrices tested, the Kruskal-Wallis and Mann-Whitney tests revealed significant differences for the 3 groups compared to the controls. For group 1Y, a significant difference (P<.001) of the internal upper diameter was found compared to the CTRL group. Compared to the controls, the nonparametric analyses for groups 3Y and 8Y showed significant differences for the internal upper diameter (P<.001) and deviations from circularity (P<.001). For groups 1Y, 3Y and 8Y, matrix thickness losses were 07, 47 and 70 μm, respectively.

CONCLUSIONS

Within the limitations of this study, it was observed that one year of clinical wear had limited effect on the ball attachment matrices. Three to 8 years of clinical use resulted in a significant decrease of matrix thickness, especially at the tip of the retentive lamellae.

Wear of ball attachments after 1 to 8 years of clinical use: a qualitative analysis

The purpose of this study was to analyze and compare scanning electron microscopy (SEM) observations of ball attachments that had been worn by patients during three periods of clinical use. One hundred forty-four specimens of ball anchor attachments (gold alloy matrix and titanium patrix) were studied by SEM after periods of approximately 1, 3.5, and 8 years of clinical use. Twenty new attachment components were examined as controls. SEM images revealed signs of mechanical wear for the ball attachments studied. The surfaces of the titanium patrix were associated primarily with roughening after short-term use, whereas surfaces of the gold alloy matrix showed wear, roughening, and loss of microscopic material in the form of flakes. Severe mechanical wear on both surfaces was noted after longer periods of use. The mechanical changes were not correlated with patient-mediated observations regarding the time-dependent retentive efficacy of the attachments. One year of clinical wear appeared to have limited effect on the ball attachment tested. Conversely, longer periods of use led to marked modifications in shape of the matrix and patrix components.