Single-Tooth Implants with Different Neck Designs: A Randomized Clinical Trial Evaluating the Aesthetic Outcome

Influence of rough micro-threaded and laser micro-textured implant-neck on peri-implant tissues: A systematic review

Background and objective

This systematic review aimed to explore clinical outcomes of marginal or crestal bone level (MBL) and soft tissue status around implants, following the placement of rough micro-threaded/laser-microtextured surface (LMS) implants. These outcomes are compared with those following the placement of smooth machined-neck implants.

Materials and methods

Using EBSCO Information Services, we conducted a web-based search of databases such as the PubMed, Scopus, and EMBASE, for relevant English-language scientific papers published between January 2013 and August 2022. Prospective or retrospective controlled cohort studies and randomized controlled trials (RCTs) investigating the role of rough micro-threaded/LMS implant necks on MBL, sulcular probing depth (PD), and/or clinical attachment loss, were included in this review.

Results

From a comprehensive literature search of 247 articles, 6 RCTs, 5 prospective studies, and 4 retrospective studies (n = 15) fulfilled the eligibility criteria. MBL with rough micro-threaded implant necks ranged from 0.12 ± 0.17 mm to 3.25 ± 0.4 mm after loading. The smooth machined-neck implants without a micro-threaded neck had a loading MBL of 0.38 ± 0.51 mm to 3.75 ± 0.4 mm. Micro-threaded implant necks showed much lower MBL than machined-neck implants. LMS implant necks had a lower peri-implant PD than machined-neck implants after 3 years of early loading (2.3 ± 0.7 mm vs. 3.8 ± 0.8 mm). The experimental and control groups showed similar gingival recessions (1.08 ± 0.4 mm vs. 2.46 ± 0.3 mm). Meta-analysis was not feasible owing to heterogeneity of the studies.

Conclusion

Under functional loading, a roughened micro-threaded design for the implant neck could significantly lower MBL. Furthermore, PD and MBL were much lower around LMS neck implants than those around machined-neck or micro-threaded implants.

The peri-implant mucosa color: A systematic appraisal of methods for its assessment and clinical significance

BACKGROUND

Peri-implant mucosa color (PMC) seems to be one of the main parameters affecting the esthetic outcome of implant therapy. However, more emphasis should be given to its assessment and reporting.

PURPOSE

To describe the available evidence on methods to assess and report the color of the peri-implant mucosa (PMC) and the respective clinical relevance.

MATERIAL AND METHODS

A comprehensive electronic and manual search was performed to identify clinical studies reporting on PMC.

RESULTS

A total of 121 studies were included. PMC was evaluated at the time of the follow-up visit (chairside) in 45.5% studies. PMC assessment was performed qualitatively, by comparing PMC with adjacent and/or contralateral gingiva (78.6%) or quantitatively, using spectrophotometry (20.7%) or a software on clinical photographs (0.8%). The most performed method to assess PMC was through esthetic indices (76.9%), either at the time of the follow-up visit (chairside) or at later time point using photographs. Quantitative reporting of PMC included averages of points from esthetic indices or color differences to natural gingiva expressed with the CIELAB color system. PMC assessment allowed describing color discrepancies compared to natural gingiva, evaluating color changes over time, and comparing the outcomes of different treatment modalities. PMC assessment through spectrophotometry was additionally utilized to assess the role of mucosal thickness (MT) on PMC.

CONCLUSIONS

Various methods for PMC assessment and reporting were described, including visual assessment, mainly through esthetic indices, and spectrophotometry. PMC evaluation has allowed to demonstrate the factors affecting the color of the peri-implant soft tissue, such as the type of abutment/restoration, MT, and soft tissue augmentation.

Covariates Relating to Implant Failure and Marginal Bone Loss of a Novel Triangular Neck-Implant Placed by Post-Graduate Students: A 1-Year Prospective Cohort Study

(1) Background: Most of the clinical literature dealing with dental implants has been issued by experienced teams working either in university settings or in private practice. The purpose of this study was to identify contributing covariates to implant failure and marginal bone loss (MBL) at the 1-year follow-up of a novel triangular-neck implant design when placed by inexperienced post-graduate students. (2) Methods: A prospective cohort study was conducted on study participants eligible for implant placement at the UIC (International University of Catalonia), Barcelona, Spain. Implant failure rate and contributors to implant failure and MBL were investigated among 24 implant and patient variables. (3) Results: One hundred and twenty implants (V3, MIS) were placed and rehabilitated by the students. The mean insertion torque was 37.1 Ncm. Survival and success rates were 97.5% and 96.7%, respectively. Implants placed in patients with smoking habits displayed a tendency of higher failure risk (OR = 5.31, p = 0.17) when compared to non-smokers. The mean (SD) MBL was 0.51 (0.44) mm. Gender significantly affected the MBL (p = 0.020). Bleeding on probing (BoP) on the buccal sites proved to be a good predictor of proximal MBL (p = 0.030). (4) Conclusions: The survival and success rates of the V3 triangular-neck implant placed by inexperienced post-graduate students at the 1-year follow-up were high and similar to the ones published in the literature by experienced teams on other implants.

Esthetic, mechanical, and biological outcomes of various implant abutments for single-tooth replacement in the anterior region: a systematic review of the literature

Background

The choice of the appropriate implant abutment is a critical step for a successful outcome. Titanium abutments have demonstrated high survival rates, due to their excellent biocompatibility and high mechanical strength, although they often result in a grayish discoloration of the peri-implant mucosa. This esthetic concern culminated in the introduction of ceramic abutments. The aim of this review was to assess the esthetic, mechanical, and biological outcomes as well as the survival of the different types of abutments used for single-implant restorations in the anterior area.

Material and methods

An electronic search was conducted in Medline, Embase, and Cochrane Central databases using the appropriate Mesh terms and predetermined eligibility criteria. The quality of the studies was assessed using the ROB 2 tool. The last search was conducted on 18th of March 2020.

Results

From the 2074 records initially identified, 23 randomized controlled trials (32 publications) were included for qualitative analysis. Data were classified based on study information, specific characteristics of the intervention and comparator, and information related to the outcome measures. Seven studies exhibited an overall low risk of bias, while twelve studies raised some concerns.

Conclusions

The rate of abutment failure was low and was associated with the ceramic abutments, especially those with internal connection. Limited correlation was noted between soft tissue thickness and color difference. Titanium abutments caused significantly more discoloration to the soft tissues than ceramic abutments, while hueing (gold or pink) slightly improved their color performance. Zirconia allowed a better color match than titanium or gold abutments, still discolored slightly the soft tissues. The submucosally modified zirconia abutments exhibited encouraging results. No significant difference was reported between materials or different types of retention on recession, papillary fill, and biological outcomes.

Peri-implant and esthetic outcomes of cemented and screw-retained crowns using zirconia abutments in single implant-supported restorations-A systematic review and meta-analysis

OBJECTIVES

To evaluate the peri-implant tissue changes and esthetic outcomes of cemented and screw-retained crowns of single-tooth implants in the esthetic zone using zirconia abutments.

MATERIAL AND METHODS

An electronic search was performed on nine databases. The risk-of-bias was assessed by the revised Cochrane risk-of-bias tool for randomized (RoB 2) and non-randomized (ROBINS-I) clinical trials. Marginal bone level change, soft tissue thickness, bleeding on probing, probing depth, survival rates of implants and crowns, complications, plaque and papilla indexes, and pink esthetic score data were extracted and analyzed. The certainty of evidence was accessed through the GRADE approach.

RESULTS

Nine records were included and 7 were used in the meta-analyses. Screw-retained crowns presented greater marginal bone level change (MD -0.04 [-0.08, -0.00] p = 0.04, I²  = 0%) compared to cemented crowns up to 1-year. At 3 and 4 years no significant differences (p > 0.05) were observed. Soft tissue thickness did not differ between groups (p > 0.05). The bleeding on probing was higher in cemented group than in screw-retained crowns at 1-year (MD 0.17 [0.08, 0.27] p = 0.0005, I²  = 0%), at medium-term periods (3 and 4 years) no statistically significant differences (p > 0.05) were observed for this outcome. Probing depth, survival rates of implants and crowns, complications, and plaque index, as well as esthetic analysis using the papilla index and pink esthetic score did not differ statistically (p > 0.05) between both retention systems at short and medium-term periods.

CONCLUSION

The connection system considering zirconia abutments presented no influence on peri-implant parameters and esthetics evaluation for medium-term periods (3 and 4 years).

A Randomized Clinical Trial Comparing Immediate Loading and Delayed Loading of Single-Tooth Implants: 5-Year Results

The aim of this prospective randomized clinical study was to compare the clinical treatment outcome for single dental implants submitted to either immediate loading (IL) or delayed loading (DL) after 5 years of follow-up. Fifty patients with a missing maxillary tooth (15–25) were randomly allocated to either the IL or DL. The treatment procedures included implant installation in healed sites, temporary screw-retained crown and replacement with a permanent single implant crown. The two groups were evaluated with regard to implant survival, marginal bone level, papillae index, pink and white esthetic score (PES, WES). At the 5-year follow-up the implant survival rate was 100% and 95.8% for IL and DL, respectively. Implant success rate was 91.7% and 83.3% for IL and DL, respectively. The mean ± SD marginal bone loss for IL and DL was −0.50 ± 0.73 mm and −0.54 ± 0.65 mm, respectively. (p = 0.782). Statistically significant less marginal bone loss was found non-smokers (p = 0.021). No statistically significant differences were found for IL and DL concerning papillae index PES and WES after 5 years. This study suggests that implant-supported single crowns in the maxillary aesthetic zone can present similar results with respect to either IL or DL after 5 years.

Alveolar ridge preservation in defect sockets in the maxillary aesthetic zone followed by single-tooth bone level tapered implants with immediate provisionalization: a 1-year prospective case series

Background

Clinical studies of single-tooth replacement in compromised bone using bone level tapered implants in the aesthetic zone are scarce.

Aim

To assess clinically, radiographically and aesthetically over 1 year the performance of a bone level tapered implant in the maxillary aesthetic zone in sites after alveolar ridge preservation.

Material and methods

Thirty patients (16 male, 14 female) with a failing tooth and large bone defect after removal received alveolar ridge preservation. After 3 months, implants were placed with immediate provisionalization. Definitive restorations were placed after 3 months. The treatment was evaluated 1 year following the definitive restoration.

Results

All the patients attended the 1-year follow-up. One implant was lost (96.7% implant survival rate). The mean implant stability quotient value was 68.9 ± 8.74 at implant placement. The mean marginal bone level change was minor (− 0.07 ± 0.12 mm). The mean mid-buccal mucosa changed with + 0.01 ± 0.45 mm. The median Pink Esthetic Score and White Esthetic Score after 1 year were 6 [4; 7] and 8 [7; 9], respectively. The patients’ mean overall satisfaction (0–100 VAS scale) was 86.6 ± 10.3.

Conclusion

Bone level tapered implants with immediate provisionalization perform well after alveolar ridge preservation in the maxillary aesthetic zone, according to implant stability, clinical, radiographic, aesthetic and patient-centred outcomes.

Trial registration

NTR, NL8755. Registered on 1 January 2016

Reproducibility and validity of anterior implant esthetic indices: A review

Background:

The purpose of this review was to narrate about the reproducibility and validity of different indices evaluating esthetic aspects in anterior single implant-supported restorations.

Materials and Methods:

An electronic search of Medline, Scopus, Embase, Cochrane Central, and Web of Science databases was performed using the keywords “dental implants,” “anterior esthetics,” “esthetic score,” and “esthetic index.” Besides, a manual search of dental implant journals was carried out.

Results:

The electronic search revealed 932 titles. After further review, 14 articles fulfilled the eligibility criteria and were included in this review. Because of the heterogeneity of the study designs, interventions, and parameters used for assessment of esthetics, no meta-analysis could be performed.

Conclusion:

Many indices have been proposed for the evaluation of the esthetic aspects of single implant-supported reconstructions in the anterior maxilla. All of them have some advantages and drawbacks that this review pointed out. The evidence level of studies used for the validation of these indices is poor. It is necessary to achieve a consensus on the tools for assessment of the esthetic aspect and perform evidence-based studies to validate an appropriate index.

A 4 Year Human, Randomized, Radiographic Study of Scalloped versus Non-Scalloped Cemented Implants

Marginal bone loss (MBL) is a key factor in long-term implant success rate. Among the different factors that influence MBL, it is the different implant shoulder designs, such as scalloped or non-scalloped, which have been widely studied on screw retained but not on cemented retained implants. Thus, the aim of the present study was to evaluate the MBL around scalloped and non-scalloped cemented retained dental implants after 4 years of loading, in humans. A total of 15 patients were enrolled in the present study. A radiographic and clinical examination was performed after implant placement (T0) and after 4 years from it (T1). The results demonstrated a differential MBL (T1-T0) of 2.436 ± 1.103 mm and 1.923 ± 1.021 mm, respectively for test (scalloped) and control (non-scalloped) groups with a statistically significant difference between them. On the other hand, no statistically significant differences were found between the groups in terms of prosthetic complication and abutment decementation, whilst ceramic crowns chipping was shown in both groups. In conclusion, the use of a scalloped platform did not provide better results on the maintenance of MBL after 4 years follow-up. In this study, this probably was determined by multiple factors, among which was the subcrestal insertion of scalloped implants.

Dental implant placement in alveolar cleft patients: a retrospective comparative study on clinical and aesthetic outcomes

The aim of this retrospective study was to assess the clinical and aesthetic outcomes, and patient satisfaction, following dental implant therapy in cleft patients. Implant survival, changes in marginal bone level, pocket probing depths, plaque and bleeding indices, aesthetics, and patient satisfaction were assessed in 17 alveolar cleft patients and 17 matched controls. At follow-up (mean 72.4±46.4 months), one implant had been lost in the cleft group. Mean marginal bone loss at follow-up was -0.4±0.4mm in cleft patients and -0.2±0.4mm in controls. Aesthetics of the peri-implant soft tissues (pink aesthetic score) were less favourable (P=0.025) in cleft patients (5.0±1.9) than in controls (6.5±1.7), while peri-implant parameters were comparable in the two groups. Overall patient satisfaction was 8.6±0.9 in cleft patients and 8.9±1.1 in controls (P=0.331). In cleft patients, no difference in aesthetics was observed between patients who received additional bone augmentation at 3 months prior to implant placement and those who did not (P=0.092). Dental implant therapy in cleft patients is associated with high implant survival, minor marginal bone loss, healthy peri-implant soft tissues, and high patient satisfaction. Only the aesthetics of the soft tissues was worse in cleft patients compared to augmented non-cleft patients.

Influence on peri-implant bone loss of different fixed partial dentures retained on 2 implants

STATEMENT OF PROBLEM

Marginal bone loss is key to determining the success of dental implants. However, how different factors, including the extension or span of implant-supported restorations and implant position, affect bone loss is unclear.

PURPOSE

The purpose of this prospective clinical study was to analyze peri-implant bone loss 3 years after loading by evaluating the influence of implant position and prosthetic type and comparing splinted crowns and 3- or 4-unit fixed partial dentures (FPDs) to determine whether 2 dental implants can achieve comparable success when replacing 2, 3, or 4 missing teeth.

MATERIAL AND METHODS

Sixty-two adjacent dental implants in 23 participants were investigated. The implants supported noncantilevered restorations: 2 splinted crowns or 3- or 4-unit FPDs. Bone loss was evaluated 3 years after loading from periapical radiographs using AutoCAD software. Nonparametric comparisons were made. The Wilcoxon test was applied to determine homogeneity of related samples. The Mann-Whitney test was applied to measure homogeneity of bone loss in 2 independent samples and the presence/absence of a pontic in the restoration (α=.05).

RESULTS

Mean ±standard deviation peri-implant bone loss was 0.9 ±0.7 mm. The peri-implant bone loss of the restorations analyzed was similar to the average values of 1.1 ±0.8 mm for 3- and 4-unit FPDs and 0.8 ±0.6 mm for splinted crowns. The type of prosthodontic restoration and implant position did not show significant influences on bone loss (P>.05).

CONCLUSIONS

Mean bone loss values were within an acceptable range. Statistically significant relationships were not found between the restoration types, suggesting that 3 or 4 missing teeth can be replaced by 2 implants. Further studies with longer follow-ups are needed to obtain clinically applicable conclusions.

Patient-reported outcome measures focusing on aesthetics of implant- and tooth-supported fixed dental prostheses: A systematic review and meta-analysis

OBJECTIVES

The aim of this systematic review and meta-analysis was to summarize the existing evidence on patient-reported aesthetic outcome measures (PROMs) of implant-supported, relative to tooth-supported fixed dental prostheses.

MATERIAL AND METHODS

In April 2017, two reviewers independently searched the Medline (PubMed), EMBASE, and Cochrane electronic databases, focusing on studies including patient-reported aesthetic outcomes of implant- and tooth-supported fixed dental prostheses (FDPs). Human studies with a mean follow-up period of at least 1 year, a minimum of ten patients, and English, German, or French publication were included. For the comparison of subgroups, random-effects meta-regression for aggregate-level data was used.

RESULTS

The systematic search for implant-supported prostheses focusing on patient-reported outcomes identified 2,675 titles, which were screened by two independent authors. Fifty full-text articles were analyzed, and finally, 16 publications (including 19 relevant study cohorts) were included. For tooth-supported prostheses, no studies could be included. A total of 816 implant-supported reconstructions were analyzed by patients. Overall aesthetic evaluation by the patients' visual analogue scale (VAS) rating was high in implant-supported FDPs (median: 90.3; min-max: 80.0-94.0) and the surrounding mucosa (median: 84.7; min-max: 73.0-92.0). Individual restorative materials, implant neck design (i.e., tissue or bone level type implants), and the use of a fixed provisional had no effect on patients' ratings of the definitive implant-supported FDPs.

CONCLUSIONS

Aesthetics is an important patient-reported measure, which lacks in standardized methods; however, patients' satisfaction was high for implant- supported FDPs and the surrounding mucosa.

Etiology and classification of food impaction around implants and implant-retained prosthesis

BACKGROUND

Food impaction is a common risk factor for the initiation of peri-implant inflammation and failure of the osseointegrated implant. Although clinicians do acknowledge the presence of food impaction around implants and implant-retained prosthesis, no classification system has yet classified the food impaction around the implant and implant-retained prosthesis.

PURPOSE

The present paper aims to identify and classify the plausible etiology of food impaction around implants and implant-related prosthesis.

MATERIALS AND METHODS

The following search terms were utilized for data search: "Food Impaction" AND "Implants" AND "Food Impaction" AND "Perimplantitis" AND "Food Impaction" AND "Classification." Articles that were written in the English language in PubMed and Cochrane Library database from 1930 till September 2018 were scrutinized. A total of 24 articles were scrutinized, out of which only 15 articles were selected.

RESULTS

Food impaction around implants is broadly classified into five categories based on the number of implants, nature of implants prosthesis involved for replacement and relation of the implant prosthesis to the adjacent tooth, restoration, or prosthesis.

CONCLUSION

This is the first classification designed to classify food impaction around dental implants and implant-retained prosthesis. The classification can be used by clinicians for optimal diagnosis, interpretation, and treatment plan for patients.

Zirconia abutments in the anterior region: A systematic review of mechanical and esthetic outcomes

STATEMENT OF PROBLEM

The success of single, anterior, implant-supported restorations relies on mechanical and esthetic outcomes. Titanium has been the most commonly used material for abutments, but zirconia is increasingly chosen for its appearance despite its unclear mechanical performance. Today, manufacturers market prefabricated, computer-aided design and computer-aided manufacturing (CAD-CAM) custom and zirconia abutments with titanium connections.

PURPOSE

The purpose of this study was to systematically review the mechanical and esthetic outcomes of implant zirconia abutments used in the anterior region, considering the design changes of the past 5 years.

MATERIAL AND METHODS

An electronic search was conducted in Medline (PubMed) for studies on zirconia abutments. All clinical studies with at least a 1-year follow-up and case series (>5 abutments) published after 2013 were included. Mechanical and esthetic outcomes were collected.

RESULTS

Of the 231 retrieved studies, 20 remained for quantitative analysis. Twelve described mechanical outcomes, and 15 focused on esthetics, using mainly the pink esthetic score. Five articles reported abutment fractures and no chipping. No difference was found between prefabricated and custom abutments or internal and external implant connections regarding fractures or screw loosening. All authors reported "good to excellent" esthetic integration in terms of restorations and soft-tissue color and the presence and height of papillae. The most difficult esthetic parameters to achieve were root convexity, soft-tissue color, and texture and level of mucosa.

CONCLUSIONS

Esthetics remain the major advantage of zirconia abutment when compared with titanium, despite reservations concerning the risk of mechanical complications. Data are lacking for zirconia abutments with titanium inserts, although the prospects for this design are promising.

Titanium dental implants with different collar design and surface modifications: A systematic review on survival rates and marginal bone levels

AIM

The aim of this study was to compare clinical and radiographic outcomes of dental implants with different neck characteristics.

METHODS

A protocol-oriented search aimed at the question: "In patients subjected to tooth replacement with screw-type dental implants does the modification of the implant neck macro- or microgeometry contribute to the improvement of survival rates and maintenance of the peri-implant marginal bone levels?" Primary outcomes were survival and marginal bone level (MBL) changes evaluated on randomized controlled trials with >10 participants and follow-up >1 year. Risk of bias was evaluated using the Cochrane Collaboration's tool. The review follows the PRISMA statement.

RESULTS

Forty-three studies compared: (a) One- versus two-piece implants (N = 7); (b) Two-piece implants with different neck characteristics (machined and rough collars, microthreads, LASER microtexturing) (N = 21); (c) Two-piece implants with macrogeometry modifications (tapering, back-tapering, and scalloping) (N = 6). One- and two-piece implants showed similar survival (RR = 0.45, 95% CI: [0.12, 1.66], p = 0.23) and MBL changes (WMD = 0.09 mm, 95% CI: [-0.27, 0.45], p = 0.64) at 1-year post-loading. Machined collar implants have higher risk of early failure than rough collar implants (RR = 3.96, 95% CI: [1.12, 13.93], p = 0.03) and 0.43 mm higher bone resorption (95% CI: [0.0, 0.86], p = 0.05). Microthreads (WMD = 0.07 mm, 95% CI: [-0.01, 0.15], p = 0.10) and LASER microtexturing (WMD = 0.15 mm, 95% CI: [-0.35, 0.65], p = 0.56) do not reduce bone resorption. Scalloped implants have 1.26 mm higher resorption (95% CI: [0.72, 2.00], p < 0.001).

CONCLUSIONS

One- and two-piece implants have similar survival and MBL changes. Rough collar implants have lower MBL changes than machined collar implants. Additional modifications to rough collars are irrelevant.

Influence of Implant Neck Design on Peri-Implant Tissue Dimensions: A Comparative Study in Dogs

This in vivo study assessed (hard and soft) peri-implant tissue remodeling around implants with micro-ring and open-thread neck designs placed in a dog model. Twenty histological sections corresponding to four different implant designs that were placed in America Foxhound dogs were obtained from previous studies. All the implants had been placed under identical conditions and were divided into four groups: Group A, micro-rings on implant neck plus 0.5 mm refined surface; Group B, micro-rings on implant neck; Group C, open-thread neck; and, Group D, double-spiral neck. Eight weeks after surgery, the integrated implants were removed and processed for histological examination. Crestal bone loss and bone-to-implant contact was greater for micro-ring necks than open-thread necks. Soft tissues showed significant differences on both buccal and lingual aspects, so that the distance from peri-implant mucosa to the apical portion of the barrier epithelium was smaller in the micro-ring groups. So, in spite of generating greater bone-to-implant contact, implants with micro rings produced more bone loss than open-thread implants. Moreover, the outcomes that were obtained IPX implants smooth neck design produced less bone loss in the cervical area, following by Facility implants when compared with the other open thread and microthreaded implant designs. Implant thread design can influence on bone remodeling in the cervical area, related to bundle bone preservation.

Esthetic evaluation of natural teeth in anterior maxilla using the pink and white esthetic scores

BACKGROUND

Natural teeth in the anterior maxilla are critical in determination the esthetic outcome of single implant prosthesis.

PURPOSE

The present study aimed to explore aesthetics of natural teeth in the anterior maxilla using the Pink Esthetic Score/White Esthetic Score (PES/WES) index. Additionally, inherent weak spots of natural teeth and high-risk parameters of prostheses were also considered.

MATERIAL AND METHODS

This cross-sectional study was performed by photographic analysis.

RESULTS

A total of 102 subjects and 306 teeth (the right incisor, lateral incisor and canine) were included. The grand means of the PES and WES were 12.92 and 8.75, respectively. The score of soft tissue margin, soft tissue contour and outline/volume of the crown were significantly lower than other variables. The PES and WES showed a downward trend with age. Most of the PES/WES values of the females exceeded those of the males.

CONCLUSION

The average level of natural teeth in PES and WES assessment were around 13 and 9, respectively. The soft tissue margin, soft tissue contour and outline/volume of the crown were high-risk parameters for the esthetic outcomes of implant reconstructions. Underlying factors, such as age and gender, contributed to the esthetics of natural teeth change.

Survival and Success Rates of Different Shoulder Designs: A Systematic Review of the Literature

Objectives

To identify whether there is a relationship between different implant shoulder positions/orientations/designs and prosthetic and/or implant failures, biological or mechanical complications, radiographic marginal bone loss (MBL), peri-implant buccal recession (RC), aesthetic scores (Papilla Index, PES, and WES), and patient satisfaction after a minimum of 1 year function in the aesthetic zone, compared to the two-piece, conventional implant neck architecture.

Materials and Methods

The systematic review was written according to the PRISMA guidelines. The search strategy encompassed the English literature from 1967 to September 2016 and was performed online (in the PubMed database of the U.S. National Library of Medicine, Embase, and the Cochrane Library) to identify relevant studies that met the inclusion criteria. The assessment of quality and risk of bias of the selected manuscripts was performed according to the guidelines provided by CONSORT and STROBE statements.

Results

A total of 16 articles (7 randomized controlled trials, 4 observational comparative studies, and 5 systematic reviews) were selected to fulfill the inclusion criteria. A trend of higher implant failure and prosthetic complications were experienced in the one-piece group compared to the two-piece group, although no statistically significant differences were found. Higher marginal bone loss was found in the test group (one-piece, scalloped implants) compared to the control group (two-piece, flat implants). No comparative studies reporting data on sloped implants were found that fulfilled the inclusion and exclusion criteria of this systematic review. No differences were experienced between groups regarding aesthetic outcomes and patient satisfaction.

Conclusions

There was sufficient evidence that different implant shoulder positions/orientations/designs (scalloped, sloped, and one piece) offer no benefit when compared to two-piece, conventional flat implants. Current evidence is limited due to the quality of available studies.

Evaluation of the influence of implant placement timing on the esthetic outcomes of single tooth implant treatment in the anterior maxilla: A retrospective study

OBJECTIVES

The purpose of this retrospective study was to investigate the influence of implant placement timing on the esthetic outcomes for single implants in the anterior maxilla.

MATERIALS AND METHODS

One hundred and ten patients (48 males; 62 females) who received a single-tooth implant after extraction either immediately (Type 1); after 4-8 weeks (Type 2); after 8-16 weeks (Type 3); or more than 16 weeks (Type 4) were evaluated in terms of esthetic outcomes after a mean post-placement interval of 26.3 months (range 12-116). Esthetic outcomes were measured using the Pink and White Esthetic Score (PES; WES). Stepwise regression analysis was performed to analyze the effect of timing of placement, as well as patient demographics and other clinical parameters on the esthetic outcomes.

RESULTS

No statistically significantly differences in PES were found between the various treatment modalities with Type 1 implants (n = 33) scoring 10.58 ± 1.65 (median: 11), followed by 10.36 ± 2.09 (median: 10.5), 9.68 ± 2.43 (median: 10), and 9.63 ± 2.21 (median: 10) for Type 2 (n = 14), Type 3 (n = 19), and Type 4 (n = 44), respectively. For immediate implants, a trend towards better esthetic outcomes was observed when implant placement was done flaplessly in cases with intact buccal bone (Type 1A, median PES 11) as compared to cases with partial/complete missing buccal plates where a flap was raised (Type 1B, median PES 10). Overall, the only parameter that influenced esthetic outcomes (as measured by PES) was gender, with females having significantly superior results. The median WES was 8 and 96% of the crowns were deemed esthetically acceptable, with crowns placed by specialist prosthodontists yielding higher scores than those placed by general practitioners.

CONCLUSIONS

Single tooth implants in the anterior maxilla showed satisfactory outcomes when measured with objective esthetic criteria. Timing of implant placement did not significantly influence the esthetic outcomes, although a trend towards better outcomes was seen with immediate implant placement as observed by higher median PES values.

CLINICAL SIGNIFICANCE

Single tooth implant placement in the anterior maxilla is a predictable treatment modality for achieving acceptable esthetic outcomes regardless of the timing of placement.

A clinical assessment of the volume of interproximal papilla after definitive prosthesis around immediate and delayed loading implants placed in the maxillary esthetic zone: An in vivo study

Background:

The presence of the dental papilla is critical to achieve esthetics in a single tooth implant restoration.

Aim:

The purpose of this study was to determine if there were differences in the papilla fill between implant and teeth comparing immediate implant placement and provisionalised single tooth implant restorations with delayed implant placement and provisionalised single tooth implant restorations. The papilla fill in these two groups was evaluated using the Jemt papilla index.

Results:

It was seen that there was no statistically significant difference seen in the volume of the papilla between both the groups. There was a statistically significant difference seen in both the groups on the distal and mesial side from the initial stage go the follow up period of 10 days, 3 months and 6 months.

Conclusion:

The interpretation of clinical papilla is a difficult task since many different clinical situations can be encountered while studying single tooth implant restorations. The single tooth implant restoration is a specific entity; the distance between the mesial and the distal side of one implant is never the same. Therefore the present study analysed the papilla as a unit and focused on the vertical fill related to the implant and adjacent teeth.

Immediate implant placement: the fate of the buccal crest. A retrospective cone beam computed tomography study

This retrospective study aimed to analyse the fate of the buccal crest after immediate implant placement (IIP) through the use of cone beam computed tomography (CBCT). In 16 consecutive patients, an implant was placed in a more palatal position after extraction, thereby creating a gap of at least 2mm between the implant and the buccal crest. Subsequently, this gap was filled with a bone substitute. Preoperatively, immediate postoperatively, and late postoperatively, a CBCT was made to measure the thickness of the buccal crest. After application of the bone substitute, the buccal crest increased in thickness from 0.9mm to 2.4mm (mean). At a mean of 103 weeks after IIP, late postoperative CBCT scans showed that the thickness of the buccal crest was compacted to 1.8mm. In the same period, the height of the buccal crest increased by 1.6mm (mean) to, on average, 1.2mm above the implant shoulder. The aesthetic outcome was analysed using the White and Pink Esthetic Score (WES and PES). Both scored high: 8.4 and 11.8, respectively. Within the limitations of this study, the results of this IIP protocol are promising. Long-term prospective research on this topic on a large number of patients is necessary.

Scalloped Implant-Abutment Connection Compared to Conventional Flat Implant-Abutment Connection: a Systematic Review and Meta-Analysis

OBJECTIVES

The objective was to test the hypothesis of no difference in implant treatment outcome after installation of implants with a scalloped implant-abutment connection compared to a flat implant-abutment connection.

MATERIAL AND METHODS

A MEDLINE (PubMed), Embase and Cochrane library search in combination with a hand-search of relevant journals was conducted. No language or year of publication restriction was applied.

RESULTS

The search provided 298 titles. Three studies fulfilled the inclusion criteria. The included studies were characterized by low or moderate risk of bias. Survival of suprastructures has never been compared within the same study. High implant survival rate was reported in all the included studies. Significantly more peri-implant marginal bone loss, higher probing depth score, bleeding score and gingival score was observed around implants with a scalloped implant-abutment connection. There were no significant differences between the two treatment modalities regarding professional or patient-reported outcome measures. Meta-analysis disclosed a mean difference of peri-implant marginal bone loss of 1.56 mm (confidence interval: 0.87 to 2.25), indicating significant more bone loss around implants with a scalloped implant-abutment connection.

CONCLUSIONS

A scalloped implant-abutment connection seems to be associated with higher peri-implant marginal bone loss compared to a flat implant-abutment connection. Therefore, the hypothesis of the present systematic review must be rejected. However, further long-term randomized controlled trials assessing implant treatment outcome with the two treatment modalities are needed before definite conclusions can be provided about the beneficial use of implants with a scalloped implant-abutment connection on preservation of the peri-implant marginal bone level.

Clinician assessments and patient perspectives of single-tooth implant restorations in the esthetic zone of the maxilla: A systematic review

STATEMENT OF PROBLEM

Esthetic outcomes associated with implant dentistry are important to both clinicians and patients. However, esthetic satisfaction may vary between the 2 groups. In order to evaluate the current publications relating to this topic, the following focused question was developed, "what are the quantitative and qualitative differences between clinician evaluations and patient perspectives in the assessment of single-tooth implant outcomes in the esthetic zone?"

PURPOSE

The purpose of this systematic review was to identify differences in esthetic satisfaction between clinicians and patients when evaluating single-tooth implant-supported restorations.

MATERIAL AND METHODS

An electronic search of the Medline database and Cochrane Central Register of Controlled Trials (2000 to 2014) was performed. The search was supplemented by a manual search of specific journals. A quality assessment of full-text articles was performed according to Cochrane Collaboration's tool and Newcastle-Ottawa scale for risk of bias assessment. Information regarding outcomes was collected and compared.

RESULTS

The search term combinations identified 555 titles. Subsequent to further review, 11 publications, including 2 randomized controlled trials, were selected for inclusion. Because of the heterogeneity of the study designs, study interventions, and esthetic assessment methods, no meta-analysis was performed. The clinicians identified a satisfactory outcome in 51% to 100% for peri-implant soft tissue and 62% to 90% for implant restorations. Patients showed a mean range score of 43% to 93% for peri-implant soft tissue and 81% to 96% for implant restorations. The visual analog scale score of the dentists was always lower than that of the patients. The review identified correlations between subjective and objective assessments for the Pink Esthetic Score (PES), the Papilla Index (PI), the Implant Crown Aesthetic Index (ICAI), and the modified (mod-ICAI) indices.

CONCLUSIONS

Clinicians are more critical of esthetic outcomes than patients. The PES and the PI correlated with the patients' responses concerning the peri-implant soft tissue. The ICAI and the mod-ICAI showed a correlation of both the peri-implant mucosa and implant-supported crown satisfaction. Thus, a comprehensive and practical index should be developed to assess the esthetic outcomes for single-tooth implant restorations in the esthetic zone.

Long-term Stability of Soft Tissue Esthetic Outcomes Following Conventional Single Implant Treatment in the Anterior Maxilla: 10-12 Year Results

Purpose:

The present study aimed to evaluate the long-term stability of esthetic outcomes of soft tissue around maxillary anterior single-tooth implants after 10-to-12 years of loading.

Methods:

Patients who had been treated for single-tooth implants in the anterior maxilla between February 2000 and July 2002 were invited to participate in the study. All implants had been placed according to delayed implant placement and conventional loading protocols without any connective tissue graft or papilla preservation flaps. Pink Esthetic Score (PES) was rated using standardized clinical photographs to assess the esthetic outcomes of the implant treatment at the time of crown placement and at time of follow-up examination which was at least 10 years after the crown placement.

Results:

A total of 19 patients were included. The mean score of PES was 11.63 (SD 1.61; range 7-14) at baseline. After 10-to-12 years of function, a mean PES score of 11.05 (SD 2.09; range 6–14) was recorded. No significant differences were found in the esthetic outcomes, categorized based on clinically relevant levels, between the baseline and follow-up session (p>0.05).

Conclusion:

Within limitation of the present study, it can be concluded that the esthetic outcomes of soft tissue around the maxillary anterior single-tooth implants placed using conventional implant placement technique remained stable in the long-term.

Evaluation of Implant Collar Surfaces for Marginal Bone Loss: A Systematic Review and Meta-Analysis

Background. It is important to understand the influence of different collar designs on peri-implant marginal bone loss, especially in the critical area. Objectives. The purpose of the present systematic review and meta-analysis was to compare dental implants with different collar surfaces, evaluating marginal bone loss and survival rates of implants. Methods. Eligibility criteria included clinical human studies, randomized controlled trials, and prospective and retrospective studies, which evaluated dental implants with different collar surface in the same study. Results. Twelve articles were included, with a total of 492 machined, 319 rough-surfaced, and 352 rough-surfaced microthreaded neck implants. There was less marginal bone loss at implants with rough-surfaced and rough-surfaced microthreaded neck than at machined-neck implants (difference in means: 0.321, 95% CI: 0.149 to 0.493; p < 0.01). Conclusion. Rough and rough-surfaced microthreaded implants are considered a predictable treatment for preserving early marginal bone loss.

Aesthetic perception of single implants placed in the anterior zone. A cross-sectional study

BACKGROUND

Several aesthetic indexes have been described to assess implant aesthetics. The aim of this study was to compare the aesthetic assessment made by dental professionals and students of single-tooth implants placed in the upper incisors.

MATERIALS AND METHODS

A cross-sectional survey study using a subjective questionnaire to assess the aesthetics in 3 implant supported single-tooth cases in the anterior maxilla was performed. The interviewed subjects were divided into 4 groups: dentist with experience in implant treatment, dentists without experience in implants and 3rd and 5th year dental students. The questionnaire consisted of 2 visual analogue scales (VAS) to evaluate aesthetics, the pink esthetic score (PES), the white esthetic score (WES) and the simplified papilla index (PI).

RESULTS

One-hundred dentists and one-hundred dental students filled the aesthetic assessment questionnaire. The results showed that the subjects were more critical than reference values, specially concerning prosthetic issues. The differences between groups were more obvious in the case with the best result. On the other hand, few differences were detected in the remaining cases. Regarding soft tissue and crown features, experienced dentists in implant dentistry were the most demanding. Cronbach's Alpha showed values ≥ 0,8 in the questionnaire in every case, which indicates an adequate reliability.

CONCLUSIONS

Dentists and dental students have different opinions when assessing aesthetics of single tooth implant supported cases. Experience and area of expertise seem to influence the evaluation of aesthetics in the anterior region.

Immediate Single-Tooth Implant Placement in Bony Defects in the Esthetic Zone: A 1-Year Randomized Controlled Trial

BACKGROUND

This study aims to assess, with regard to marginal bone level (MBL), whether the outcome of immediate implant placement in bony defects in the esthetic zone was non-inferior to delayed implant placement after 1 year.

METHODS

Forty patients with a failing tooth in the esthetic zone and a labial bony defect of ≥5 mm after removal of a tooth were randomly assigned for immediate (n = 20) or delayed (n = 20) implant placement. Second-stage surgery and provisionalization occurred after 3 months of healing. Follow-up was at 1 month and 1 year after definitive crown placement. The study was powered to detect a difference in MBL of >0.9 mm. Buccal bone thickness, soft tissue peri-implant parameters, esthetic indices, and patient satisfaction were also assessed.

RESULTS

One year after definitive crown placement, MBL loss was 0.56 ± 0.39 mm mesially and 0.74 ± 0.51 mm distally for the immediate placement group and 0.51 ± 0.43 mesially and 0.54 ± 0.45 distally mm for the delayed placement group, respectively (not significant). Regarding differences in means, non-inferiority was observed after 1 year (difference in mean for immediate versus delayed: mesially 0.04 mm [95% confidence interval (CI) = -0.22 to 0.30 mm, P = 0.40]; distally 0.21 mm [95% CI = -0.10 to 0.51 mm, P = 0.58]). No significant differences in the other outcome variables were observed.

CONCLUSIONS

Immediate implant placement with delayed provisionalization was non-inferior to delayed implant placement with delayed provisionalization in labial bony defects of ≥5 mm regarding change in MBL. Although not powered for other outcome variables, no clinically relevant differences were observed in these variables.

The Immediate Aesthetic and Functional Restoration of Maxillary Incisors Compromised by Periodontitis Using Short Implants with Single Crown Restorations: A Minimally Invasive Approach and Five-Year Follow-Up

The functional and aesthetic restoration of teeth compromised due to aggressive periodontitis presents numerous challenges for the clinician. Horizontal bone loss and soft tissue destruction resulting from periodontitis can impede implant placement and the regeneration of an aesthetically pleasing gingival smile line, often requiring bone augmentation and mucogingival surgery, respectively. Conservative approaches to the treatment of aggressive periodontitis (i.e., treatments that use minimally invasive tools and techniques) have been purported to yield positive outcomes. Here, we report on the treatment and five-year follow-up of patient suffering from aggressive periodontitis using a minimally invasive surgical technique and implant system. By using the methods described herein, we were able to achieve the immediate aesthetic and functional restoration of the maxillary incisors in a case that would otherwise require bone augmentation and extensive mucogingival surgery. This technique represents a conservative and efficacious alternative to the aesthetic and functional replacement of teeth compromised due to aggressive periodontitis.

Feasibility of immediate placement of single-tooth implants in the aesthetic zone: a 1-year randomized controlled trial

AIM

To assess whether outcome of immediate implant placement and immediate provisionalization after 1 year was non-inferior to immediate implant placement and delayed provisionalization regarding Marginal Bone Level (MBL).

MATERIALS AND METHODS

Forty patients with a failing tooth in the aesthetic zone were randomly assigned for immediate implant placement with immediate (n = 20) or delayed (n = 20) provisionalization. Follow-up was at 1 month and after 1 year. The study was powered to detect a difference in MBL of <0.9 mm. Apart from MBL, soft tissue peri-implant parameters, aesthetic indexes and patient satisfaction were assessed.

RESULTS

After 1 year, MBL changes were -0.75 ± 0.69 mesially and -0.68 ± 0.65 distally mm for the immediate group and -0.70 ± 0.64 and -0.68 ± 0.64 mm for the delayed group respectively (NS). Regarding differences in means, non-inferiority was observed after 1 year (mesially: Group A versus B: difference in mean 0.08 mm (95% CI -0.38 to 0.53, p = 0.71 distally: Group A versus B: difference in mean 0.09 mm (95% CI -0.37 to 0.56 mm, p = 0.66).No significant differences in the other outcome variables were observed.

CONCLUSIONS

This study showed that immediate placement and immediate provisionalization was non-inferior to immediate placement with delayed provisionalization. In addition, although not powered for these outcome variables, no clinically relevant differences in other outcomes were observed (www.isrtcn.com: ISRCTN57251089).

Esthetic Evaluation of Implant Crowns and Peri-Implant Soft Tissue in the Anterior Maxilla: Comparison and Reproducibility of Three Different Indices

BACKGROUND

A successful implant reconstruction with optimal esthetics consists of a visually pleasing prosthesis and complete and healthy surrounding soft tissue. In the current literature, numerous indices used to qualitatively assess esthetics have been described. However, studies comparing the indices and their reproducibility are scarce.

PURPOSE

The aim of this study was to compare three different esthetic indices for the evaluation of single implant-supported crowns.

MATERIALS AND METHODS

A total of 10 prosthodontists (P), 10 orthodontists (O), 10 general dentists (G), and 10 lay people (L) independently performed the same assessment using 30 photographs and corresponding casts with three different esthetic indices (Peri-Implant and Crown Index [PICI], Implant Crown Aesthetic Index [ICAI], "Pink Esthetic Score/White Esthetic Score [PES/WES]) and repeated the evaluations 4 weeks later.

RESULTS

The PES/WES and the PICI showed significantly higher esthetic scores (pink, white, total) and clinical acceptance compared with the ICAI in all four groups and in both assessments. The highest intraobserver agreement was achieved using the PES/WES and the least with the ICAI. The mean Kappa per group ranged from 0.18 (group L with ICAI) to 0.63 (group G with PICI).

CONCLUSION

In comparison with the ICAI, the PES/WES and PICI were more reproducible. Therefore, PES/WES and PICI seem to be more suitable as esthetic indices for single implant crowns.

Esthetic failure in implant dentistry

The definition of failure for dental implants has evolved from lack of osseointegration to increased concern for other aspects, such as esthetics. However, esthetic failure in implant dentistry has not been well defined. Although multiple esthetic indices have been validated for objectively evaluating clinical outcomes, including failure of an implant-supported crown, only one author has determined a failure threshold. On the basis of objective indices, esthetic failures in implant dentistry can be categorized as pink-tissue failures and white-tissue failures. This article discusses esthetic failures, the factors involved in these failures, and their prevention and treatment.

Fresh-Socket Implants of Different Collar Length: Clinical Evaluation in the Aesthetic Zone

BACKGROUND

The aim of this clinical study was to compare clinical evaluations of implants in the aesthetic zone with smooth collars of different length.

MATERIALS AND METHODS

Sixty-six patients requiring extractions of one, two, or three teeth in the aesthetic zone of the maxilla were enrolled in this study. Ninety-four implants were positioned and were loaded immediately after tooth extraction. Forty-seven implants with a short smooth collar of 0.5 mm (SCI) and 47 implants with a long smooth collar of 1.8 mm (LCI) were utilized in this study and were placed using a nonsubmerged approach. Clinical (gingival index, modified plaque index, modified bleeding index, probing depth, gingival recession) and intraoral digital radiographic parameters were measured at baseline and after 6, 12, 24, and 36 months of healing to evaluate crestal bone loss levels over time.

RESULTS

After a follow-up period of 36 months, a survival rate of 100% was reported. The SCI group showed a mean bone loss of 1.07 ± 0.38 mm at 12 months and 1.09 ± 0.38 mm at 36 months. The LCI group showed a mean bone loss of 0.46 ± 0.14 mm at 12 months and 0.53 ± 0.12 mm at 36 months. After the 36-month follow-up period, both groups showed stable bone levels over time. Statistically significant differences were found between groups (p < .05). No statistically significant differences were found between SCI and LCI groups with regard to clinical parameters over time.

CONCLUSIONS

This study revealed significant differences in radiographically observed marginal bone loss between the two types of implant with different smooth-collar lengths, but no differences in gingival vestibular margin outcome were observed.

Disparity in embrasure fill and papilla height between tooth- and implant-borne fixed restorations in the anterior maxilla: a cross-sectional study

PURPOSE

The objective of the present study was to compare inter-proximal fill and papilla height between different embrasures.

MATERIAL & METHODS

One hundred and fifty non-smoking consecutive patients (mean age 54, range 32-73; 63 males and 87 females) without periodontal disease were selected in a multidisciplinary practice during regular supportive care. All had been treated for multiple tooth loss in the anterior maxilla at least 1 year earlier by means of a fixed restoration on teeth (n = 50) or implants (n = 100) using straightforward procedures (without hard and/or soft tissue augmentation). Embrasure fill was assessed by means of Jemt's papilla index and papilla height was registered following local anaesthesia by means of bone sounding by one clinician.

RESULTS

Tooth-pontic and tooth-implant embrasures demonstrated comparable inter-proximal fill and papilla height (≥58% Jemt's score 3; mean papilla height ≥4.1 mm). Between missing teeth, embrasure fill and papilla height were lower regardless of the embrasure type. The implant-implant and implant-pontic embrasure demonstrated comparable outcome (≤42% Jemt's score 3; mean papilla height ≤ 3.3 mm; p ≥ 0.416), which was significantly poorer when compared to the pontic-pontic embrasure (82% Jemt's score 3; mean papilla height 3.7 mm; p ≤ 0.019). Overall, papilla index and papilla height demonstrated a weak correlation (Spearman's correlation coefficient: 0.198; p = 0.002).

CONCLUSIONS

The re-establishment of a papilla is difficult when there is no tooth involved. In that scenario a short papilla should be expected and implant-borne restorations demonstrate the poorest outcome. Moreover, an implant with a pontic may not perform better than adjacent implants.