A prospective clinical cohort study analyzing single-unit implant crowns after three years of loading: introduction of a novel Functional Implant Prosthodontic Score (FIPS)

Monolithic Hybrid Abutment Crowns (Screw-Retained) Versus Monolithic Hybrid Abutments With Monolithic Crowns (Adhesively Cemented): Three-Year Data of a Prospective Clinical Split-Mouth Study

OBJECTIVES

This study compares the restoration of single-tooth implants with screw-retained lithium-disilicate hybrid-abutment crowns and single-tooth lithium-disilicate crowns adhesively bonded to hybrid abutments with regard to objective clinical and subjective patient-specific evaluation criteria over a time of observation of 3 years.

MATERIALS AND METHODS

Two bone-level implants were placed in contralateral sides of the same jaw in 10 patients, each with two single-tooth gaps. After osseointegration, implants were uncovered and an impression was taken. In accordance with the split-mouth design, one implant in each patient was restored with a screw-retained hybrid abutment crown and the other implant with a hybrid abutment and an adhesively bonded single-tooth crown. The restorations were randomly allocated to the implants. Prefabricated titanium bases were used. The ceramic abutments and restorations were fabricated monolithically with pressed lithium-disilicate ceramic. An objective evaluation (survival, technical, or biological complications, FIPS) by the practitioner and a subjective evaluation (satisfaction, OHIP) by the patient were carried out after 3, 6, 12, 24, and 36 months after restoration placement.

RESULTS

Both restoration types showed a survival rate of 100% after 3 years of observation. No technical or biological complications occurred. No significant difference was observed between the two types of restoration neither for objective (survival, technical or biological complications, FIPS) nor subjective (satisfaction, OHIP) evaluation criteria (p > 0.05).

CONCLUSION

No statistically significant differences were observed between screw-retained and cemented pressed lithium-disilicate restorations on bone-level implants for both objective and subjective evaluation criteria, respectively.

CLINICAL SIGNIFICANCE

Monolithic hybrid-abutment crowns (screw-retained) and monolithic hybrid abutments with single-tooth crowns (cemented) made of pressed lithium disilicate can be used to successfully restore single implants.

A comparative study of the use of digital technology in the anterior smile experience

OBJECTIVES

this study aims to compare the clinical outcomes of traditional and digital crown extension guides in the aesthetic restoration of anterior teeth. Additionally, the study will analyze the differences in the results of various digital crown extension guides in anterior aesthetic restorations.

METHODS

Sixty-two patients who required aesthetic restoration of their anterior teeth were selected for this study. The patients had a total of 230 anterior teeth and were randomly divided into three groups: a control group of 22 cases who received diagnostic wax-up with pressure film, an experimental group 1 of 20 cases who received 3D printed digital models with pressure film, and an experimental group 2 of 20 patients who received digital dual-positioning guides. The control group had a total of 84 anterior teeth, experimental group 1 had 72 anterior teeth, and experimental group 2 had 74 anterior teeth. The study compared three methods for fabricating crown extension guides: the control group used the diagnostic wax-up plus compression film method, while experimental group 1 used compression film on 3D printed models and experimental group 2 used 3D printed digital dual-positioning crown extension guides. After the crown lengthening surgery, the control group patients wore DMG resin temporary crown material for gingival contouring, while the experimental group patients wore 3D printed resin temporary crowns for the same purpose. The patients were followed up in the outpatient clinic after wearing temporary crowns for 1 month, 3 months, and 6 months, respectively. The clinical results were evaluated in terms of marginal fit, red aesthetic index, and white aesthetic index.

RESULTS

Based on the statistical analysis, the experimental group required significantly fewer follow-up visits and less time for guide design and fabrication compared to the control group. Additionally, the surgical time for the experimental group was significantly shorter than that of the control group. During the postoperative period between the 1st and 3rd month, the PES index scores for the marginal gingival level, proximal, and distal mesiodistal gingival papillae of the experimental group showed a trend of superiority over those of the control group. By the 6th month, the marginal gingival level exhibited a significant difference between the experimental and control groups. The experimental group demonstrated superior results to the control group in terms of shape, contour, and volume of the teeth, color, surface texture, and transparency of the restorations, and features during the 1st and 3rd postoperative months. In the 6th month, the comparative results indicated that the experimental group continued to exhibit superior outcomes to the control group in terms of the shape, color, surface texture, and transparency of the restorations, as well as the characteristics of the teeth. Additionally, the experimental group demonstrated significantly fewer gingival alterations than the control group at 1 month, 3 months, and 6 months post-procedure, with this difference being statistically significant. Furthermore, the combination of 3D printing technology and restorative techniques was utilized, resulting in consistent patient satisfaction.

CONCLUSION

Digitalisation plays an important role in anterior aesthetic restorations. The use of digital technology to manage the entire process of anterior cosmetic restorations can improve restorative results, reduce the number of follow-up appointments, shorten consultation time, and achieve better patient satisfaction.

Assessment of reproducibility and influence of different dental specialties on functional implant prosthodontic score: A prospective clinical study analyzing single-unit implant crowns

AIM

Implant therapy in partially edentulous patients has become the most adapted and predictable treatment modality. The success rate of implants has been measured in terms of esthetic, biological, and technical factors such as radiographic bone loss, prosthetic complications, and stability. Despite the existence of several indices for the esthetic assessment of implant crowns, a need for functional evaluation of the implant crown with an objective and reproducible score has arisen. The study aims to validate the reproducibility of the functional implant prosthodontic score (FIPS) and the influence exerted by different dental specialties while evaluating posterior single-unit implant crowns.

STUDY SETTING AND DESIGN

This was a prospective clinical study.

MATERIALS AND METHODS

Fifteen patients with cement-retained single-implant crowns in the posterior region of the jaws were included. Eight examiners, two prosthodontists, two periodontists, two oral surgeons, and two orthodontists evaluated 15 photographs of single-unit implant crowns during the 1-year follow-up examination. The examiners assessed the photographs for FIPS, which includes five parameters for objectively evaluating the single-unit implant crowns. Assessments were performed twice at a gap of 4 weeks.

STATISTICAL ANALYSIS USED

Pearson's correlation with a 95% confidence interval was calculated for the intra-examiner and the Kruskal-Wallis test for inter-examiner reproducibility.

RESULTS

The mean total FIPS scores for all included examiners were 7.133 for time T1 and 7.074 for time T2, showing a strong Pearson correlation coefficient for intra-examiner reproducibility. No significant difference was analyzed among different specialties with statistically significant values of the Kruskal-Wallis test.

CONCLUSION

Intra- and inter-examiner analysis showed very consistent results during the reproducibility assessment of FIPS. The results validated the use of FIPS as a long-term predictive functional evaluation tool for the single-implant crowns in posterior sites irrespective of the effect of different dental specialties. It could be used for risk estimation and prognosis for long-term survival and performance of implant crowns.

Clinical performance of monolithic lithium disilicate hybrid abutment crowns over at least 3.5 years

PURPOSE

Hybrid abutment crowns (HACs) made from monolithic ceramics represent an efficient option for single restorations on implants. However, long-term data are scarce. The purpose of this clinical trial was to evaluate the survival and complication rates of CAD-CAM fabricated HACs over a time period of at least 3.5 years.

MATERIALS AND METHODS

Twenty-five patients with a total of 40 HACs made of monolithic lithium disilicate ceramic bonded to a titanium base CAD-CAM abutment were retrospectively evaluated. All implants and screw-retained restorations were placed and manufactured in the same department of a university hospital. Only crowns that had been in service for more than 3.5 years were included in the study. HACs were evaluated regarding technical and biological complications. Functional Implant Prosthodontic Scores (FIPS) were obtained.

RESULTS

The mean observation time was 5.9 ± 1.4 years. Implant survival was 100%, and HAC survival was 97.5%. Over the observation period, one crown fracture was observed, necessitating refabricating of the restoration. Three minor biological complications were found. The overall mean FIPS score was 8.69 ± 1.12 points.

CONCLUSIONS

Within the limitations of this study, monolithic screw-retained HACs milled from lithium disilicate ceramics and bonded to titanium bases appeared to be a reliable treatment option over more than 3.5 years due to their low biological and technical complication rates.

Comparison of functional and esthetic outcomes in digital versus analog rehabilitation of one-piece screw-retained implant crowns placed at second stage surgery

PURPOSE

Analog and digital impressions are established procedures for restoration of single-tooth implants. In this study, single-tooth implants were restored with definitive restorations during second-stage surgery. Analog and digital workflows were compared.

MATERIAL AND METHODS

Eighty single-tooth implants were examined in total. In 40 implants, an index was taken immediately after implant placement using composite resin to fabricate the final crowns (analog workflow). For the other 40 single-tooth implants, intraoral intraoperative scans were performed (digital workflow) during primary surgery. The custom-fabricated screw-retained crowns were placed during second-stage surgery. Photographs and examinations for the scores were taken at the time of the follow-up visit, 1-4 years after placement of the crowns. The number of treatment appointments required was recorded and the modified pink esthetic score (PES) was determined. Additionally, the functional implant prosthetic score (FIPS) was measured.

RESULTS

The mean PES was 12.15/14 for the digital workflow and 11.95/14 for the analog workflow. The most common deficit was incomplete papillae for both workflows. Three treatment appointments were required for both workflows: (1) Scan and/or impressions making and patient consent, (2) implant placement, and (3) second-stage surgery with crown insertion. The FIPS was 9.1/10 for the digital workflow group and 9.2/10 for the analog workflow group. Common deficits presented as missing papillae as well as open approximal contacts. The FIPS was not significantly different between workflows (p = 0.679). The PES also did not show a statistically significant difference for both workflows (p = 0.654), however, the analog workflow showed better values for the papillae (p < 0.05). A significant difference was also found in the other PES values, with the digital workflow showing better results here (p < 0.05). A chronological analysis of the results of the digital technique showed that the cases treated last had significantly better values than the cases treated first.

CONCLUSIONS

According to the results of this study, both workflows allowed placement of the definitive crowns on single-tooth implants during second-stage surgery. Both workflows were found to be equivalent in terms of esthetic results in this study, although the digital workflow demonstrated a learning curve.

Clinical evaluation and quantitative occlusal change analysis of posterior implant-supported all-ceramic crowns: A 3-year randomized controlled clinical trial

OBJECTIVES

To compare the survival and complication rates of posterior screw-retained monolithic lithium disilicate (LS2 )/veneered zirconia (ZrO2 ) single implant crowns (SICs), as well as analyze the occlusal changes observed during a 3-year follow-up period.

MATERIALS AND METHODS

Thirty-three patients were included and randomly divided into two groups. The test group consisted of 17 patients who received monolithic-LS2 -SIC, while the control group consisted of 16 patients who received veneered-ZrO2 -SIC. Implant/prosthesis survival rates, technical complications, peri-implant soft tissue conditions, and quantitative occlusal changes of SIC (obtained by the intra-oral scanner and analyzed in reverse software Geomagic Control 2015) were assessed at 1- and 3-year follow-ups. Bone loss and Functional Implant Prosthodontic Score (FIPS) were evaluated at a 3-year follow-up.

RESULTS

After a 3-year follow-up period, one patient dropped out of the follow-up. No implant loss was observed. One crown was fractured, resulting in prosthesis survival rates of 93.75% for the monolithic group and 100% for the veneered group. A technical complication rate of 25% (4/16) was observed in the veneered group (p = .333). No significant differences in the marginal bone loss were observed at the 3-year follow-up (0.00 (-0.22, 0.17) mm versus 0.00 (-0.12, 0.12) mm, p = .956). The total FIPS scores for the test group were 9.0 (9.0, 9.0), while the control group received scores of 9.0 (8.0, 10.0) (p = .953). The changes in mean occlusal clearance were 0.022 ± 0.083 mm for the test and 0.034 ± 0.077 mm for the control group (at 3 years, p = .497). The changes in occlusal contact area were 1.075 ± 2.575 mm2 for the test and 1.676 ± 2.551 mm2 for the control group (at 3 years, p = .873).

CONCLUSION

After a 3-year follow-up, screw-retained monolithic LS2 and veneered ZrO2 SIC demonstrated similar survival rates. The occlusal performance of implant prostheses needs to be closely examined during follow-up, and appropriate occlusal adjustments need to be considered.

Root-analogue implants compared to forced orthodontic extrusion: a retrospective analysis of clinical, radiological and esthetic outcomes after restoration

OBJECTIVES

To assess clinical, radiological and esthetic outcomes of restorations supported by root-analogue implants (RAIs) or roots of severely damaged teeth after forced orthodontic extrusion (FOE).

MATERIALS AND METHODS

Clinical data regarding milled one-piece (titanium/zirconia roots and zirconia abutments) RAIs (REPLICATE™ System) and FOE were recorded and retrospectively evaluated for 40 patients by two investigators. Strict inclusion and exclusion criteria were applied. Functional and esthetic outcomes were assessed for n = 20 pre-molars and n = 20 anterior teeth via comparison of radiographic and digital images applying the novel Functional Implant Prosthodontic Score (FIPS). Krippendorff's alpha coefficient was calculated to assess inter-rater reliability. Mann-Whitney-U-Test was used to compare the assessed parameters. Level of significance was set to p < 0.05.

RESULTS

After a mean observation period of 18.4 ± 5.7 months for restorations supported by RAIs and 43.9 ± 16.4 months for restorations after FOE, mean FIPS scores were 9.2/8.8 ± 1.1/1.2 (RAIs) and 7.4/7.7 ± 1.3/1.5 (FOE), respectively. Krippendorff's alpha coefficients did not reveal unacceptable inter-rater reliabilities regarding the investigators and applicability of FIPS. Significant differences were documented when comparing restorations after FOE or supported by RAIs regarding bone loss (p < 0.01), presence of papillae (p < 0.05) and quality and quantity of mucosa (p < 0.02) in favor of FOE.

CONCLUSIONS

Within the main limitations of sample size and the retrospective study design, both concepts seem to provide clinically acceptable results.

CLINICAL RELEVANCE

Bone- and tissue-preserving characteristics regarding the concept of FOE are promising. It could be applicable for socket preservation and subsequent conventional implant placements in an adapted workflow.

The Influence of the Clinicians' Experience on the Outcome of Dental Implants: A Clinical Audit

The purpose of this outcome audit is to evaluate the influence of the clinicians' experience on the outcome of dental implants. In addition, it is to identify the associated risk factors that might influence the success and survival of these implants.

METHODOLOGY

The records of patients treated with SLA/SLActive Straumann implants were screened. This enabled us to have a minimum of 12 months of follow-up. Eligible patients, according to the inclusion criteria, were contacted and invited to undergo a follow-up assessment. Success was accounted for and defined in a comprehensive manner by considering four different categories: implant perspective, peri-implant soft tissue perspective, prosthetic perspective, and patient satisfaction. The patient investigations included a clinical examination of the implant mobility, suppuration, width of keratinized mucosa, probing depth, plaque accumulation, prosthetic complications, and patient satisfaction. In addition, a periapical radiograph was taken to evaluate bone loss and peri-implant radiolucency. The data were analysed using SPSS version 26.

RESULTS

Thirty-eight patients with 84 SLA/SLActive Straumann implants were available for the assessment. The mean age of the patients at implant surgery was 49.05 ± 13.19 years. Over the mean follow-up period of 26 months, no implant fractures were noted. Overall, eight implants were considered failures (9.5%). Two out of six patients with a history of periodontitis (HoP) and two out of five smokers exhibited failed implants. The patients' satisfaction responses showed that all the responses were statistically higher than the test median value of three. The median value of general satisfaction using a visual analogue scale was 9 out of 10.

CONCLUSIONS

The implants placed on partially and fully edentulous patients revealed high survival and success rates (100% and 90.5%, respectively) at a mean follow-up time of 26 months. It can be concluded that the implant practise among trainees in the programme is satisfactory. A history of periodontitis and a lack of patient compliance with supportive periodontal therapy in some cases have been shown to be risk factors associated with increased implant failure, mainly peri-implantitis.

Monolithic hybrid abutment crowns (screw-retained) versus monolithic hybrid abutments with adhesively cemented monolithic crowns

OBJECTIVES

The objective of this study is to compare monolithic hybrid abutment crowns (screw-retained) versus monolithic hybrid abutments with adhesively cemented monolithic single-tooth crowns.

MATERIALS AND METHODS

Twenty subjects in need of an implant-borne restoration were randomly assigned to receive either a cement-retained (CRR) or a screw-retained (SRR) implant-supported monolithic lithium disilicate (LS₂ ) reconstruction. Each patient received a titanium implant with in internal conic connection. After osseointegration and second-stage surgery, healing abutments were placed for about 10 days. The type of restoration (CRR vs. SRR) was randomly assigned, and the restorations were manufactured of monolithic LS₂ . Both types of restorations, CRR and SRR, were based on a titanium component (Ti-base) that was bonded to the abutment (CRR) or the crown (SRR). The follow-up period for all restoration was 36 months. Clinical outcome was evaluated according to Functional Implant Prosthetic Score (FIPS). Quality of live (OHIP) and patient's satisfaction were assessed using patient-reported outcome measures (PROMs). Primary endpoint was loss of restoration for any reason. Kaplan-Meier curves were constructed and log-rank testing was performed (p < .05).

RESULTS

One restoration of group CRR failed after 6 months due to loss of adhesion between Ti-base and individual abutment. No further biological or technical failures occurred. Kaplan-Meier analysis showed no significant difference between both treatment options (p = .317). There was no statistically significant difference between both types of restoration, neither for FIPS, OHIP, treatment time nor patient satisfaction (p > .05).

CONCLUSION

Monolithic hybrid abutment crowns (screw-retained) and monolithic hybrid abutment with adhesively cemented monolithic crowns using lithium disilicate showed no statistically significant difference for implant-based reconstructions in this pilot RCT setting.

Patient-reported outcome measures compared to professional dental assessments of monolithic ZrO2 implant fixed dental prostheses in complete digital workflows: A double-blind crossover randomized controlled trial

PURPOSE

This double-blind randomized controlled trial analyzed patient-reported outcome measures in terms of subjective patient satisfaction compared to objective dental evaluation of prosthetic treatment with 3-unit monolithic zirconium dioxide implant fixed dental prostheses (iFDPs) in 3 digital workflows.

MATERIAL AND METHODS

Twenty patients were restored with 3 iFDPs each on Straumann TL-implants with 2 completely digital workflows using different intraoral optical scanning systems with model-free fabrication of the restoration (Trios 3/3Shape [Test-1]; Virtuo Vivo/Straumann [Test-2]), and mixed analog-digital workflow with conventional impressions and digitized gypsum casts (Impregum/3M Espe [Control]). The order of impression-taking and the prosthetic try-in were randomly allocated. Sixty iFDPs were compared for patient satisfaction and dental evaluation using ANOVA.

RESULTS

For iFDP evaluation, patients generally provided more favorable ratings than dental experts, regardless of the workflow. ANOVA revealed no significant difference for overall satisfaction when comparing Test-1, Test-2, or Control, either for patients (f-ratio: 0.13; p = 0.876) or dentist (f-ratio: 1.55: p = 0.221). Secondary, patients clearly favored the digital impression workflows over the conventional approach (f-ratio: 14.57; p < 0.001). Overall, the 3Shape workflow (Test-1) received the highest scores for all analyses.

CONCLUSIONS

The different digital workflows demonstrated minor influence on the subjective and objective evaluation of the monolithic zirconium dioxide iFDPs in nonesthetic regions; however, the dentist may significantly increase patient satisfaction by choosing intraoral scanning instead of conventional impressions. The dentist has to consider individual patients' needs to fulfill their expectations for a personalized solution.

Clinical assessment of different implant-supported esthetic crown systems fabricated with semi-digital workflow: Two-year prospective study

OBJECTIVE

To assess the clinical outcome of three esthetic implant-supported crown systems fabricated with semi-digital workflow and their influence on the clinical outcome of dental implants.

MATERIAL AND METHODS

A total of 30 participants had received dental implants restoring missing maxillary first/second premolars. After 6 weeks, customized zirconia abutments were early loaded. Two months later, the definitive crowns were fabricated using semi-digital workflow and cemented. According to the crown material, 3 groups were randomly allocated; group (Z): ultrahigh-translucent monolithic zirconia, group (C): resin-matrix ceramic and group (P): polyetherketoneketone veneered with light-cured composite resin. Clinical outcomes including the survival and success rates were evaluated at baseline, 6, 12, 18, and 24 months.

RESULTS

The survival rate for all studied groups was 100%, while their success rate was 100% for group (Z) and 90% for group (C) and group (P). Based on the functional implant prosthodontic score, a statistically significant difference was detected between group (Z) and group (P) (p < 0.001) as well as between group (C) and group (P) (p = 0.01).

CONCLUSIONS

The zirconia group had the most favorable clinical behavior, while the polyetherketoneketone had the least. All crown systems had comparable success rates with similar values of the peri-implant marginal bone loss.

CLINICAL SIGNIFICANCE

Using semi-digital workflow, ultrahigh-translucent monolithic zirconia, resin-matrix ceramic and polyetherketoneketone veneered with light-cured composite resin can be considered as favorable implant-supported crowns. The implant-supported crown system based on polyetherketoneketone veneered with light-cured composite resin is counted as a promising esthetic and restorative option.

Patient-reported outcome measures (PROMs) comparing digital and conventional workflows for treatment with posterior single-unit implant restorations: A randomized controlled trial: PROMs comparing digital & conventional workflows

OBJECTIVES

The aim of this randomized controlled trial (RCT) was to analyze patient-reported outcome measures (PROMs) of prosthetic therapy with monolithic implant crowns in completely digital workflows (test) with intraoral optical scanning (IOS) and conventional workflows (control) with conventional impressions. Secondary, an objective evaluation of the final implant restorations was performed using the Functional Implant Prosthodontic Score (FIPS).

MATERIALS AND METHODS

Forty patients who required an implant-supported single crown on posterior regions were randomly divided into test (n=20) and control (n=20) groups for impression taking. Each group was then equally separated into two subgroups according to the restorative material used: lithium disilicate (LS2, N!CE®, Straumann AG, Basel, Switzerland) or polymer-infiltrated ceramic networks (PICN, Enamic®, Vita, Bad Säckingen, Germany). Patient satisfaction was evaluated using PROM questionnaires with visual analog scales (VAS) after impression-taking and 1 week after prosthetic delivery. Patient satisfaction with the impression technique was assessed in six domains: length, comfort, anxiety, taste, nausea, and pain, whereas patient satisfaction with the final restoration was assessed in four domains: overall treatment outcome, functionality, esthetics, and cleanability. In addition, the final implant restorations were objectively assessed by an independent prosthodontist using the FIPS. Mann-Whitney U test was used to analyze the defined outcomes. Statistical analysis was completed with a level of significance set at α=0.05.

RESULTS

PROMs focusing on the impression technique demonstrated higher levels of patient satisfaction for IOS compared to conventional impressions, especially in terms of "taste irritation" (p=0.036); whereas no significant differences were found between both restorative CAD/CAM-materials. Mean FIPS values demonstrated similar results among subgroups.

CONCLUSIONS

Within the limitation of this study, both completely digital and conventional protocols provided great levels of patient satisfaction in implant rehabilitation of single-tooth gaps in posterior sites with monolithic implant crowns. The restorative material, LS2 versus PICN, does not impact patient satisfaction with their treatment. However, long-term followed up is required to ensure patient' satisfaction with the restorations.

Time-efficiency and cost-analysis comparing three digital workflows for treatment with monolithic zirconia implant fixed dental prostheses: A double-blinded RCT

OBJECTIVES

This double-blinded randomized controlled trial investigated economic performance indicators (EPI) in terms of time-efficiency and production costs of 3-unit monolithic zirconium-dioxide (ZrO2) implant fixed dental prostheses (iFDP) in three different workflows.

METHODS

Twenty patients with two Straumann Tissue-Level-Implants received three iFDPs; two were fabricated in proprietary complete digital workflows with intraoral optical scanning and model-free fabrication with company-related CAD/CAM lab-software while one iFDP was manufactured on digitized casts from conventional impressions. The sequence of impression-taking for the three workflows (TRIOS 3/3Shape [Test-1]; Virtuo Vivo/Dental Wings [Test-2]; Impregum/3M Espe [Control]) was randomly allocated. Sixty iFDPs bonded to ti-base abutments were analyzed. Clinical and technical worksteps for Test-1/Test-2/Control were recorded and evaluated for time-efficiency including cost-analysis (CHF=Swiss Francs) using ANOVA-Tests (significance level α=0.05).

RESULTS

Mean total work time, as the sum of clinical plus technical steps, was 97.5 min (SD ± 23.6) for Test-1, 193.1 min (SD ± 25.2) for Test-2, and 172.6 min (SD ± 27.4) for Control. Times were significantly different between Test-1/Test-2 (p < 0.00001), Test-1/Control (p < 0.00001), and Test-2/Control (p < 0.03610). Technical costs were 566 CHF (SD ± 49.3) for Test-1, 711 CHF (SD ± 78.8) for Test-2, 812 CHF (SD ± 89.6) for Control, and were also significantly different for all comparisons (p < 0.00001).

CONCLUSIONS

Test-1 demonstrated the best performance for time-efficiency, Test-2 revealed the worst result. This indicates that digital workflows are not the same and not necessarily superior to analog workflows of monolithic ZrO2 iFDPs. Complexity decreases by reducing the number of steps following complete digital workflows, resulting in lower production costs compared to the mixed analog-digital workflow with conventional impressions.

CLINICAL SIGNIFICANCE

Complete digital workflows comprising intraoral optical scanning without physical models for treatment with monolithic ZrO2 iFDPs is an efficient alternative to mixed analog-digital workflows with conventional impressions and labside digitization of dental casts.

The direct digital workflow in fixed implant prosthodontics: a narrative review

BACKGROUND

The purpose of this narrative review was to examine the applicability of IOS procedures regarding single and multiple fixed implant restorations. Clinical outcomes for monolithic zirconia and lithium disilicate restorations produced through a direct digital workflow were reported.

METHODS

A MEDLINE (Pubmed) search of the relevant English-language literature spanning from January 1st 2015 until March 31st 2020 was conducted. In vitro studies comparing digital implant impression accuracy by different IOS devices or in vitro studies examining differences in accuracy between digital and conventional impression procedures were included. Also, RCTs, clinical trials and case series on the success and/or survival of monolithic zirconia and lithium disilicate restorations on implants, manufactured completely digitally were included. In vitro and in vivo studies reporting on restorations produced through an indirect digital workflow, case reports and non-English language articles were excluded. The aim was to investigate the accuracy of IOS for single and multiple fixed implant restorations compared to the conventional impression methods and report on the variables that influence it. Finally, this study aimed to report on the survival and success of fixed implant-retained restorations fabricated using the direct digital workflow.

RESULTS

For the single and short-span implant sites, IOS accuracy was high and the deviations in the position of the virtual implant fell within the acceptable clinical limits. In the complete edentulous arch with multiple implants, no consensus regarding the superiority of the conventional, splinted, custom tray impression procedure compared to the IOS impression was identified. Moreover, complete-arch IOS impressions were more accurate than conventional, non-splinted, open or close tray impressions. Factors related to scanbody design as well as scanner generation, scanning range and interimplant distance were found to influence complete-arch scanning accuracy. Single implant-retained monolithic restorations exhibited high success and survival rates and minor complications for short to medium follow-up periods.

CONCLUSIONS

The vast majority of identified studies were in vitro and this limited their clinical significance. Nevertheless, intraoral scanning exhibited high accuracy both for single and multiple implant restorations. Available literature on single-implant monolithic restorations manufactured through a complete digital workflow shows promising results for a follow-up of 3-5 years.

Rehabilitation of one-piece screw-retained implant crowns placed at second-stage surgery-a retrospective patient series

OBJECTIVES

To evaluate the esthetic and functional rehabilitation of single implants delivering the final crown during second-stage surgery.

MATERIALS AND METHODS

In 26 single-tooth implants, the impressions were taken immediately after implant placement to fabricate the final crowns. During the second-stage surgery, the screw-retained hybrid crowns were delivered. Six months to 3 years after placement of the crown, a modified pink esthetic score (PES) was measured. Additionally, the number of treatment sessions was recorded. The mesial and distal contact points and the static and dynamic occlusion were examined. Patients' satisfaction was measured using a questionnaire.

RESULTS

In this retrospective study, 21 posterior and 5 anterior implants were included. The average pink esthetic score was 11.3 out of 14. The most frequent limitations were incomplete papillae and deficits of the alveolar ridge. The average number of appointments was three, consisting of impression taking and surgery consent, implant placement, and crown delivery. Average patients' satisfaction was 46.7 out of 50 and thus, extremely high.

CONCLUSIONS

The presented approach allows the second-stage surgery and delivery of the final restoration for single-tooth implants in the same session. As the peri-implant mucosa is adapted to the final restoration in the first place, a more natural emergence profile is achieved. However, there is an increasing risk for reduced or missing papillae. Patients' satisfaction is generally very high.

CLINICAL RELEVANCE

A method for direct definitive prosthetic restoration during the exposure of single-tooth implants is examined, advantages and disadvantages will be described, and patient acceptance is validated.

A pilot trial on lithium disilicate partial crowns using a novel prosthodontic functional index for teeth (FIT)

Background

Lithium disilicate is now a well accepted material for indirect restorations. The aim of this trial was to evaluate two lithium disilicate systems using a novel prosthodontic Functional Index for Teeth (FIT).

Methods

Partial adhesive crowns on natural abutment posterior teeth were made on sixty patients. Patients were divided into two groups: Group 1 IPS e.max press (Ivoclar-Vivadent, Schaan, Liecthestein), and Group 2 Initial LiSi press (GC Co., Tokyo, Japan). The restorations were followed-up for 3 years, and the FIT evaluation was performed at last recall. The FIT is composed of seven variables (Interproximal, Occlusion, Design, Mucosa, Bone, Biology and Margins), each of them are evaluated using a 0–1-2 scoring scheme, and is investigated by an oral radiograph and occlusal and buccal pictures. More in details, three variables have the three scores made on the presence or not of major, minor or no discrepancy (for ‘Interproximal’, ‘Occlusion’ and ‘Design’), presence or not of keratinized and attached gingiva (‘Mucosa’), presence of bone loss > 1.5 mm, < 1.5 mm or not detectable (‘Bone’), presence or not of Bleeding on Probing and or Plaque Index (‘Biology’), presence of detectable gap and marginal stain or not (‘Margins’). The Mann-Whitney ‘U’ test was used and the level of significance was set at p < 0.05. Also, “success” of the crowns (restoration in place without any biological or technical complication) and “survival” (restoration still in place with biological or technical complication) were evaluated.

Results

Regarding FIT scores, all partial crowns showed a stable level of the alveolar crest without detectable signs of bone loss in the radiographic analysis. All other evaluated parameters showed a high score, between 1.73 and 2. No statistically significant difference emerged between the two groups in any of the assessed variables (p > 0.05). All FIT scores were compatible with the outcome of clinical success and no one restoration was replaced or repaired and the success rate was 100%.

Conclusions

The results showed that it is possible to evaluate the clinical performance of partial crowns using FIT. The FIT proved to be an effective tool to monitor the performance of the restorations and their compatibility with periodontal tissues at the recall. The FIT can be really helpful for a standardized evaluation of the quality of the therapy in prosthodontic dentistry. The two lithium disilicate materials showed similar results after 3 years of clinical service.

Trial registration

The study protocol was approved by the Ethical Committee of University of Siena (clinicaltrial.gov # NCT 01835821), ‘retrospectively registered’.

Peri-Implant Soft Tissue Conditioning by Means of Customized Healing Abutment: A Randomized Controlled Clinical Trial

INTRODUCTION

An optimal aesthetic implant restoration is a combination of a visually pleasing prosthesis and adequate surrounding peri-implant soft tissue architecture. This study describes a novel workflow for one-step formation of the supra-implant emergence profile.

MATERIALS AND METHODS

Two randomized groups were selected. Ten control group participants received standard healing screws at the surgical stage. Ten individualized healing abutments were Computer aided Design/Computer aided Manufacturing (CAD/CAM)-fabricated out of polyether ether ketone (PEEK) restoration material in a fully digital workflow and seated at the surgical stage in the test group. The modified healing abutment shape was extracted from a virtual library. The standard triangulation language (STL) files of a premolar and a molar were obtained considering the coronal anatomy up to the cement-enamel junction (CEJ). After a healing period ranging from 1 to 3 months depending on the location of the surgical site, namely, mandible or maxilla, a digital impression was taken. The functional implant prosthodontics score (FIPS) and the numerical rating scale (NRS) of pain were recorded and compared.

RESULTS

The mean FIPS value for the test group was 9.1 ± 0.9 while the control group mean value was 7.1 ± 0.9. In the test group, pain assessment at crown placement presented a mean value of 0.5 ± 0.7. On the contrary, the control group showed a mean value of 5.5 ± 1.6.

CONCLUSIONS

Patients in the test group showed higher FIPS values and lower NRS scores during the early phases compared to the control group.

CAD/CAM implant crowns in a digital workflow: Five-year follow-up of a prospective clinical trial

BACKGROUND

Implant restorations became the first choice for single-tooth replacement today.

PURPOSE

The prospective clinical trial aims to investigate computer-aided-design (CAD)/computer-aided-manufacturing (CAM)-processed implant crowns after 5 years of loading.

MATERIALS AND METHODS

Twenty patients were included for cement-retained crowns in posterior sites. Radiographic analysis of bone levels was performed after delivery and follow-up. The Functional Implant Prosthodontic Score (FIPS) was assessed at the final follow-up. Wilcoxon signed-rank tests were used with a level of significance set at α = 0.05.

RESULTS

One implant was lost, resulting in a success rate of 95% at 5 years. For 19 crowns, neither technical complications nor biological complications were observed. The mean marginal bone level was 0.6 ± 0.26 mm (range: 0.18-1.12) mesially, and 0.79 ± 0.36 mm (range: 0.23-1.36) distally at 5 years. During the observation period, mean radiographic bone levels increased significantly by 0.23 mm at mesial and by 0.17 mm at distal sites (P < .0001) indicating minor additional bone loss. The mean total FIPS score was 8.2 ± 1.0 (range: 7-10) with the high score of 2.0 ± 0.0 for the variable "bone."

CONCLUSIONS

CAD/CAM-processed implant crowns demonstrated promising radiographic and clinical outcomes after 5 years in function. Future large-scale trials are crucial to confirm these initial results in the field of digital implant processing.

Patient Reported Outcome Measures (PROMs) of posterior single-implant crowns using digital workflows: A randomized controlled trial with a three-year follow-up

OBJECTIVES

The aim of this RCT was to analyze Patient Reported Outcome Measures (PROMs) of implant crowns processed in complete digital workflows (test) and combined analog-digital workflows (control) with a three-year follow-up. This is a second reporting from the same trial with sample size calculation based on time efficiency.

MATERIALS AND METHODS

Twenty participants were selected for single-tooth replacement with screw-retained crowns in posterior sites (Straumann TL Implant System). Ten patients each were treated with test or control workflows and evaluated after 1 week of prosthetic delivery (baseline) and 3 years. The subjective opinion of the patient was assessed using visual analog scales (VAS) for PROMs; the Functional Implant Prosthodontic Score (FIPS) for the objective evaluation of the dentist. Wilcoxon signed-rank tests and Mann-Whitney U-tests were used for comparisons between test and control with a level of significance set at α = 0.05.

RESULTS

In test and control, implant crowns showed 100% survival without technical and/or biological complications. Mean PROMs varied between 81.6 and 90.3 with no difference between test and control, or between baseline and after 3 years for intra-patient comparison. Linear regression analysis exhibited a significant correlation between FIPS and PROMs related to overall treatment satisfaction (VAS-1: coefficient 0.45; p = 0.0472).

CONCLUSION

Subjective patient's perception (PROMs) of posterior implant crowns processed in complete digital and combined analog-digital workflows revealed comparable high levels of satisfaction on the overall treatment outcome including function, esthetics, and cleanability after 3 years. The objective evaluation of the dentist (FIPS) seems to reflect the perception of the patients.