Definitive Abutments Placed at Implant Insertion and Never Removed: Is It an Effective Approach? A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Influence of repeated implant-abutment manipulation on the prevalence of peri-implant diseases in complete arch restorations. A retrospective analysis

PURPOSE

To evaluate the effects of repeated abutment manipulation on the prevalence of peri-implant diseases.

MATERIALS AND METHODS

A total of 27 edentulous patients (n = 108 implants) immediately restored with double-crown retained implant-supported prostheses were identified for this retrospective study. The test included the one-abutment, one-time care concept (n = 18 patients, n = 72 implants, OAOT) and the control abutment replacement (n = 9 patients, n = 36 implants, AR). A mixed effects model regression was conducted for the variable diagnosis (healthy, peri-implant mucositis, and peri-implantitis) with predictors abutment replacement (presence/absence), number of abutment replacement, category of keratinized mucosa (KM) (2 < KM ≥2 mm), and radiographic bone loss (BL).

RESULTS

After 3-15 years (mean 10.2 ± 2.8 years), the prevalence of peri-implant mucositis and peri-implantitis in patients in the AR group was 11.1% and 88.9%, corresponding to 22.2% and 55.6% at the implant level, respectively. In OAOT group, none of the implants showed peri-implant mucositis, whereas the prevalence for peri-implantitis at patient and implant level amounted to 5.6% and 5.6%, respectively. The increased number of abutment replacements was significantly associated with the increased probability to diagnose peri-implant mucositis and peri-implantitis (OR: 6.13; 95% CI [2.61, 14.39]) (p < 0.001), whereas the presence of keratinized mucosa was not founded as a significant cofounder. The estimated mean BL in AR group was 1.38 mm larger than in OAOT group (p = 0.0190).

CONCLUSIONS

The OAOT concept was associated with a lower prevalence of peri-implant diseases.

Timing implant provisionalization: Decision-making and systematic workflow

OBJECTIVE

Provisionalization is an important step to achieve esthetic results in implant cases, and many different techniques for provisional restoration fabrication have been described. However, depending on the clinical scenario, the provisionalization strategy will require different approaches and timing. The clinician should modify the provisional restorations efficiently to reduce the number of disconnections from the implant, as repeated disconnections may have biological consequences. This article aims to schematize different scenarios requiring implant provisionalization and propose strategies to help the clinician condition the peri-implant tissues, respecting perio-prosthodontic fundamentals for soft tissue, biological, and esthetic stability.

CLINICAL CONSIDERATIONS

The clinical outcomes of modern implant therapy aim to achieve results that emulate natural dentition. Different scenarios may require adjunct therapy, including hard- and soft-tissue grafting, which complicates treatment. The provisionalization strategy will vary depending on the initial condition of the tissues, the need for reconstructive procedures, and the timing of implant placement. Selecting the right strategy based on the case type is necessary to reduce treatment time and complications associated with inadequate prosthetic handling of the soft tissues.

CLINICAL SIGNIFICANCE

Proper emergence profile conditioning through provisional restorations will allow for biologically sound and esthetically pleasing outcomes in implant restorations.

How do the dimensions of peri-implant mucosa affect marginal bone loss in equicrestal and subcrestal position of implants? A 1-year clinical trial

INTRODUCTION

There is evidence that the apico-coronal implant position and the mucosal phenotype can affect the extent of peri-implant bone loss. This clinical trial analyzes the bone remodeling and marginal bone loss that occur around conical-connection implants placed equicrestally and subcrestally, assessing the effect of the peri-implant soft-tissue phenotype.

METHODS

Fifty-one patients received 56 implants of distinct diameters (3.5 mm Ø n = 6; 4.3 mm Ø n = 41; 5 mm Ø n = 9) in the posterior part of the maxilla or mandible. The implants were placed equicrestally, 1 mm subcrestally and >1 mm subcrestally, depending on the initial supracrestal tissue height (STH). After 3 months of non-submerged healing, single metal-ceramic screw-retained implant-supported crowns were placed. Longitudinal measurements of STH, mucosal thickness and keratinized mucosa width (KMW) were made at the time of implant placement (T0), crown placement (T1), and after 3 (T2) and 6 months (T3) of prosthetic loading. At each of these points, a radiographic evaluation of bone remodeling and marginal bone loss was also performed.

RESULTS

STH was significantly greater for implants placed >1 mm subcrestally than for those placed 1 mm subcrestally. After 12 months of follow-up, a very significant (p < 0.001) loss of KMW was observed, in addition to a marginal bone loss of 0.08 ± 0.1, 0.15 ± 0.2, and 0.14 ± 0.2 mm in the groups placed equicrestally, 1 mm subcrestally and >1 mm subcrestally, respectively. After the multiple linear regression, marginal bone loss was found to depend primarily on KMW (β = -0.43), while also being affected by STH (β = 0.32) and implant diameter (β = -0.28).

CONCLUSIONS

Marginal bone loss may be influenced by the position with respect to the bone crest, as well as the KMW, STH, and implant diameter. However, more well-controlled studies are needed to verify these above-mentioned findings with different implant designs and connections.

Immediate Loading Using the Digitalized Customized Restoration of Single-tooth Implants Placed in Fresh Extraction Sockets in the Aesthetic Anterior Maxilla: A 10-Year Prospective Study of Marginal Bone Level

AIM

The objective of this study was to assess marginal bone level around single implants inserted in fresh extraction sockets in the anterior maxillary region and instantly restored with computer-aided design/computer-aided manufacturing customized temporary crowns cemented on the final abutment.

MATERIALS AND METHODS

A total of 20 patients (15 females and 5 males, with a mean age of 30 years), where 20 were placed in fresh extraction sockets. After raising a full-thickness flap, atraumatic extraction was performed the implant site was prepared and fixtures were stabilized on the palatal bone wall. The implant location was immediately transmitted to the prepared master model using the pick-up impression coping seated in the surgical guide template. Prefabricated abutments were used as the final abutment on the master model, scanned and the crown was planned using computer-aided manufacturing customized software. Later on 8th weeks, abutments were torqued as per the manufacturer's recommendation, and the final crowns were cemented. Using personalized intraoral radiographs marginal bone level was evaluated mesially and distally to the implant shoulder as a reference at implant placement, 8 weeks, 1, 3, 5, and 10 years after loading.

RESULTS

Wholly implants were osteo-integrated positively after 10 years of practical loading, but only 18 were available for clinical and radiological follow-up, and 2 patients with two implants were excluded from the study due to relocation abroad without any implant failure. The average marginal bone loss (MBL) in the current report was 0.16 ± 0.167 mm at crown cementation, 0.275 ± 0.171 mm after 1 year, 0.265 ± 0.171 mm after 3 years, 0.213 ± 0.185 mm after 5 years, and 0.217 ± 0.194 mm at 10 years.

CONCLUSION

The strategy of inserting and not removing the final abutment at the time of implant placement facilitates the establishment of adequate attachment of both soft and hard tissues to the abutment surface, ensuring uninterrupted organization of tissue architecture and offers advantages in helping maintain soft tissue maturation and preventing marginal bone level.

CLINICAL SIGNIFICANCE

Immediately loaded implants in freshly extracted sockets lead to a significant reduction in marginal ridge resorption. The use of a temporary crown on a prefabricated abutment, exclusive of successive abutment manipulation, proved effective in preserving the primarily founding blood clot and served as a prototype for shaping the soft tissue around the previously wounded gum. How to cite this article: Berberi A, El Zoghbi A, Aad G, et al. Immediate Loading Using the Digitalized Customized Restoration of Single-tooth Implants Placed in Fresh Extraction Sockets in the Aesthetic Anterior Maxilla: A 10-Year Prospective Study of Marginal Bone Level. J Contemp Dent Pract 2024;25(3):213-220.

A biologically oriented preparation technique (BOPT) for immediate posterior implant placement, immediate provisionalization, and definitive implant crown fabrication: A complete digital workflow

OBJECTIVE

Immediate implants and immediate alveolar sealing have been a widely utilized treatment with high predictability and biological advantages. The improvement in technology has made it possible to simplify clinical processes. The aim of the present report was to describe the complete digital workflow of the Biologically oriented preparation technique for immediate posterior implant, immediate provisionalization and fabrication of definitive implant crowns.

CLINICAL CONSIDERATIONS

The surgical process and prosthetic management to preserve the gingival contours of the extracted natural tooth during immediate implant placement and provisionalization are described. Additionally, during the same clinical intervention, the definitive intraoral digital implant scans for capturing the implant position, peri-implant tissue contours, adjacent and antagonist dentition, and profile emergence of the interim implant crown are captured for the fabrication of the definitive crown.

CONCLUSIONS

Based on the technique described, the immediate implant placement and provisionalization in the posterior area provides biological and clinical advantages, reducing the number of abutment-implant disconnections and the number of clinical appointments, as well as increases patient comfort.

CLINICAL SIGNIFICANCE

The present article describes a technique for an immediate implant placement and provisionalization in the posterior region for maintaining the gingival architecture of the extracted tooth. During the same appointment, the implant position, peri-implant tissue contours, and adjacent and antagonist dentition, and profile emergence of the interim implant crown are captured by using an intraoral scanner and used for the fabrication of the definitive crown. This technique aims to reduce the number of abutment-implant disconnections and clinical appointments.

Achieving optimal implant esthetics using a team approach: Part 2 treatment options, treatment coordination, and integration of digital technology

The second part of this JPD Digital presentation focused on the treatment planning, treatment coordination, and execution of implant therapy. The clinical application of the evidence-based criteria in implant therapy was emphasized including the surgical parameters, restorative parameters, and implant features reviewed in part 1. The objective was to achieve predictable results that improve the longevity of the implant and restoration, maintain peri-implant health, and optimize the esthetic outcome. Examples of several clinical scenarios of single tooth replacement treatment in the esthetic zone were reviewed by using options that included immediate placement, immediate loading, and resin-bonded interim restoration. In addition, patients requiring multiple implants, combinations of tooth-supported and implant-supported restorations, and a complete arch prosthesis supported by implants were presented. Many clinically challenging patients can be treated more effectively by using a digital workflow to plan and execute implant therapy.

Achieving optimal implant esthetics using a team approach Part 1 a review of evidence-based criteria in implant treatment

As dental implants have evolved into a universally accepted treatment option, it is essential to identify nuances of the peri-implant complex and their impact on treatment given the increasing evidence of peri-implantitis and implant loss. A thorough knowledge of anatomy and biology, careful treatment planning, correct placement, prosthetic and occlusal design, and proper long-term maintenance all play a role in dental implant therapy. The goal of this part 1 presentation is to review evidence-based criteria in implant treatment including the surgical and restorative parameters, and the desired implant features, with the objective of achieving predictable results that improve the longevity of the implant and restoration, maintain peri-implant health, and optimize the esthetic outcome. By following science-based guidelines, implant treatment can be improved and simplified with more predictable results, especially in the esthetic zone, where demands are greater and there is less room for error.

Can radiomic features extracted from intra-oral radiographs predict physiological bone remodelling around dental implants? A hypothesis-generating study

AIM

The rate of physiological bone remodelling (PBR) occurring after implant placement has been associated with the later onset of progressive bone loss and peri-implantitis, leading to medium- and long-term implant therapy failure. It is still questionable, however, whether PBR is associated with specific bone characteristics. The aim of this study was to assess whether radiomic analysis could reveal not readily appreciable bone features useful for the prediction of PBR.

MATERIALS AND METHODS

Radiomic features were extracted from the radiographs taken at implant placement (T0) using LifeX software. Because of the multi-centre design of the source study, ComBat harmonization was applied to the cohort. Different machine-learning models were trained on selected radiomic features to develop and internally validate algorithms capable of predicting high PBR. In addition, results of the algorithm were included in a multivariate analysis with other clinical variables (tissue thickness and depth of implant position) to test their independent correlation with PBR.

RESULTS

Specific radiomic features extracted at T0 are associated with higher PBR around tissue-level implants after 3 months of unsubmerged healing (T1). In addition, taking advantage of machine-learning methods, a naive Bayes model was trained using radiomic features selected by fast correlation-based filter (FCBF), which showed the best performance in the prediction of PBR (AUC = 0.751, sensitivity = 66.0%, specificity = 68.4%, positive predictive value = 73.3%, negative predictive value = 60.5%). In addition, results of the whole model were included in a multivariate analysis with tissue thickness and depth of implant position, which were still found to be independently associated with PBR (p-value < .01).

CONCLUSION

The combination of radiomics and machine-learning methods seems to be a promising approach for the early prediction of PBR. Such an innovative approach could be also used for the study of not readily disclosed bone characteristics, thus helping to explain not fully understood clinical phenomena. Although promising, the performance of the radiomic model should be improved in terms of specificity and sensitivity by further studies in this field.

Atraumatic intraoral scans and virtual hybrid casts for custom implant abutments and zirconia implants: Accuracy of the workflow

STATEMENT OF PROBLEM

Making impressions of 2-piece implants is typically associated with the repeated disassembly and reassembly of superstructures and related to soft-tissue trauma. Intraoral scanning of 1-piece zirconia implants is problematic because scan bodies are not readily available. Whether using virtual hybrid casts generated by merging intraoral scan data with the known surface geometry of abutments can solve these difficulties is not clear because data on accuracy of the workflow are sparse.

PURPOSE

The purpose of this in vitro study was to evaluate the accuracy of virtual hybrid casts with respect to the impact of different gingival situations. The workflow was designed to render pointless the use of impression posts and scan bodies and avoid any displacement of the gingiva.

MATERIAL AND METHODS

The mandibular right first molar in a typodont was replaced with a 2-piece titanium implant with a custom abutment and then a 1-piece zirconia implant. Three situations representing different gingival heights covering the abutments were simulated. Twelve intraoral scans were made for each situation to capture the recordable parts of the abutments, and virtual hybrid casts were constructed by superimposing and merging the intraoral scan data with the original laboratory scan data of the abutments. Hybrid casts were compared with reference data by using the root mean square error. Scan body-related and cast scan-related protocols were performed representing conventional digital workflows. Statistical analysis with the Kolmogorov-Smirnov, Kruskal-Wallis, and Mann-Whitney U tests with the Bonferroni correction was conducted with a statistical software program (α=.05).

RESULTS

Deviation was low in the hybrid casts of the custom abutment when the entire abutment was recorded (6.5 μm; IQR: 3.0 μm), when the preparation margin was disguised (7.0 μm; IQR: 1.0 μm), and when half of the abutment was covered (8.0 μm; IQR: 4.0 μm). The accuracy in the 1-piece zirconia implant was 10.0 μm (IQR: 4.0 μm) when the whole surface of the abutment was visible and 12.5 μm (IQR: 6.0 μm) when the preparation margin was covered. When only half of the abutment was captured, a larger deviation of 22.0 μm (IQR: 7.0 μm) was observed. The hybrid cast concept demonstrated superior accuracy compared with protocols using scan bodies (76.0 μm; IQR: 27.0 μm) and cast scans (23.0 μm; IQR: 15.0 μm).

CONCLUSIONS

Digital intraoral scanning and the generation of virtual hybrid casts provide high accuracy and are suitable for the fabrication of single-implant-supported restorations. The atraumatic procedure avoids tissue manipulation and reduces clinical effort.

Influence of buccal and palatal bone thickness on post-surgical marginal bone changes around implants placed in posterior maxilla: a multi-centre prospective study

BACKGROUND

Numerous clinical variables may influence early marginal bone loss (EMBL), including surgical, prosthetic and host-related factors. Among them, bone crest width plays a crucial role: an adequate peri-implant bone envelope has a protective effect against the influence of the aforementioned factors on marginal bone stability. The aim of the present study was to investigate the influence of buccal and palatal bone thickness at the time of implant placement on EMBL during the submerged healing period.

METHODS

Patients presenting a single edentulism in the upper premolar area and requiring implant-supported rehabilitation were enrolled following inclusion and exclusion criteria. Internal connection implants (Twinfit, Dentaurum, Ispringen, Germany) were inserted after piezoelectric implant site preparation. Mid-facial and mid-palatal thickness and height of the peri-implant bone were measured immediately after implant placement (T0) with a periodontal probe and recorded to the nearest 0.5 mm. After 3 months of submerged healing (T1), implants were uncovered and measurements were repeated with the same protocol. Kruskal-Wallis test for independent samples was used to compare bone changes from T0 to T1. Multivariate linear regression models were built to assess the influence of different variables on buccal and palatal EMBL.

RESULTS

Ninety patients (50 females, 40 males, mean age 42.9 ± 15.1 years), treated with the insertion of 90 implants in maxillary premolar area, were included in the final analysis. Mean buccal and palatal bone thickness at T0 were 2.42 ± 0.64 mm and 1.31 ± 0.38 mm, respectively. Mean buccal and palatal bone thickness at T1 were 1.92 ± 0.71 mm and 0.87 ± 0.49 mm, respectively. Changes in both buccal and palatal thickness from T0 to T1 resulted statistically significant (p = 0.000). Changes in vertical bone levels from T0 to T1 resulted not significant both on buccal (mean vertical resorption 0.04 ± 0.14 mm; p = 0.479) and palatal side (mean vertical resorption 0.03 ± 0.11 mm; p = 0.737). Multivariate linear regression analysis showed a significant negative correlation between vertical bone resorption and bone thickness at T0 on both buccal and palatal side.

CONCLUSION

The present findings suggest that a bone envelope > 2 mm on the buccal side and > 1 mm on the palatal side may effectively prevent peri-implant vertical bone resorption following surgical trauma.

TRIAL REGISTRATION

The present study was retrospectively recorded in a public register of clinical trials ( www.

CLINICALTRIALS

gov - NCT05632172) on 30/11/2022.

Simultaneous prosthodontic treatment for crowns of natural teeth and dental implants using digital technology: A case report

The aim of this clinical report was to describe the improvement of masticatory disorders with the use of digital technology to simultaneously perform prosthodontic treatment of natural teeth and edentulous areas. Computer-guided implant surgery was performed, and crown prostheses and implant superstructures were fabricated simultaneously using digital technology.

Marginal bone changes around platform-switched conical connection implants placed 1 or 2 mm subcrestally: A multicenter crossover randomized controlled trial

INTRODUCTION

This study analyzes early marginal bone modifications occurring around platform-switched implants with conical connection placed 1 or 2 mm subcrestally.

METHODS

This crossover randomized controlled trial enrolled partially edentulous patients needing two implants in either the posterior maxilla or mandible. Each patient received two platform-switched implants with conical connection inserted 2 mm (Test) and 1 mm (Control) subcrestally. Definitive abutments were immediately connected and, after 4 months of unsubmerged healing, screwed metal-ceramic crowns were delivered. Radiographs were taken at implant placement (T0), prosthesis delivery (T1), and after 1 year of prosthetic loading (T2).

RESULTS

Fifty-one patients (25 males and 26 females; mean age 61.2 ± 12.1 years) totaling 102 implants were included in the final analysis. Mean peri-implant bone level (PBL) reduction from T0 to T2 was not significantly different around Test (0.49 ± 0.32 mm) and Control implants (0.46 ± 0.35 mm; p = 0.66). Multivariate linear regression models highlighted a significant positive correlation between history of periodontitis and PBL reduction. At T2, no Test group implant and 6 Control group implants exhibited PBL below the implant platform (11.8% of Control group implants).

CONCLUSION

No significant differences in peri-implant marginal bone changes were demonstrated after 1 year of prosthetic loading between platform-switched implants with conical connection inserted either 1 or 2 mm subcrestally. However, 2 mm subcrestal placement resulted in deeper implant positioning at T2, with no exposure of treated implant surface and potential preventive effect against subsequent peri-implant pathology.

Does the Prosthetic Phase of Dental Implants Justify the Prescription of Preventive Antibiotics in Healthy Patients? A Systematic Review

Recently published surveys data show that the routine prescription of preventive antibiotics (PA) in the prosthetic phase of dental implants is more common than might be expected. The present study aimed to answer the PICO (population, intervention, comparison, and outcome) question "In healthy patients starting the implant prosthetic phase, does the prescription of PA compared with not prescribing PA decrease the incidence of infectious complications?" by a systematic literature review. A search was performed in 5 databases. The criteria employed were those described in the PRISMA Declaration. Studies included were those that provided information on the need to prescribe PA in the prosthetic phase of implants, that is, in second-stage surgeries, impression-taking, and prosthesis placement. The electronic search identified 3 studies that met the established criteria. The prescription of PA in the prosthetic phase of implants does not show a justified benefit/risk ratio. Preventive antibiotic therapy (PAT) may be indicated in the second stages or in peri-implant plastic surgery procedures lasting more than 2 hours and/or where soft tissue grafts are used extensively. In these cases, given the current lack of evidence, it is recommended to prescribe 2 g of amoxicillin 1 hour before surgery and, in allergic patients, to prescribe 500 mg of azithromycin 1 hour preoperatively.

Clinical performance of immediately placed and restored progressive-type implants in the esthetic zone: a prospective observational study

PURPOSE

To assess implant success and survival of immediately placed and restored progressive-type implants in the esthetic zone.

MATERIAL AND METHODS

A total of n = 21 patients (21 implants) had received an immediate placement of a tapered, two-part implant with a progressive thread design (PL) for a single tooth replacement in the anterior maxilla. An immediate 'non full-functional loaded' restoration was provided upon adequate primary stability on a final patient-specific abutment (one abutment-one time concept). The final restoration was provided at 12 weeks (baseline). Implant survival and success (e.g. bleeding on probing-BOP, probing pocket depth-PD, mucosal recession-MR, pink esthetic score-PES) as well as patient- reported outcomes (PROM`S) were recorded at 6 and 12 months.

RESULTS

An adequate primary implant stability (i.e. insertion torque > 35 Ncm) was obtained at all but one sites. At 12 months, implant survival (n = 20 patients) amounted to 100%. Non-significant changes to baseline were noted for mean BOP (2.5 ± 28.2%), PD (- 0.26 ± 0.73 mm), and MR (0.0 ± 0.4 mm) values. PES values amounted to 12.9 ± 1.14 and 13.2 ± 0.84 at 6 and 12 months. Technical and mechanical complications were not observed. Patients expressed an overall high satisfaction.

CONCLUSIONS

The presented immediacy protocol was associated with high survival and success rates on the short-term.

Clinical Outcomes of Dental Implants with Two Different Internal Connection Configurations—A RCT

Background: The aim of the present study was to highlight clinical and radiographical differences among implants sharing the same macro-geometry but with two different prosthodontic connections. Methods: Patients requiring at least 2 implants in the posterior area of the jaw were randomly divided into two groups (Conical (CS) and Internal Hexagonal (IH) connection). At implant surgery (T0), insertion torque, implant stability quotient (ISQ values recorded by resonance frequency analysis, RFA), and soft tissue thickness (STH) were assessed. A 1-abutment/1-time protocol was applied, and the prosthesis was realized following a fully digital workflow. At the 36-month follow-up periapical x-rays were taken. In order to statistically analyse differences among the two groups and the different variables, paired T-test was used. Linear regression analysis was conducted to analyze how marginal bone loss (MBL) was affected by other independent variables. A neural network created to predict the success (good or not good) of the implant itself was implemented. Results: 30 out of 33 patients (14 males, 16 females, mean age: 68.94 ± 13.01 years) (32 CS and 32 IH) were analyzed. No implants failed. Marginal bone loss at the 3-year time-point was 0.33 ± 0.34 mm and 0.43 ± 0.37 mm respectively for CS and IH with a significant difference between the two groups (p = 0.004). The presence of keratinized gingiva (p = 0.034) significantly influenced MBL. Conclusions: Both the implant connections investigated presented optimal clinical outcomes with minimal marginal bone loss; however, CS implants and implants with the presence of a greater width of keratinized tissue presented significantly lower MBL.

Influence of apico-coronal positioning of tissue-level implants on marginal bone stability during supracrestal tissue height establishment: A multi-center prospective study

INTRODUCTION

Supracrestal tissue height establishment is a crucial factor influencing peri-implant marginal bone modifications prior to prosthesis delivery. If mucosal thickness is insufficient, peri-implant marginal bone resorption occurs to allow appropriate supracrestal tissue height formation. This study evaluates if marginal bone resorption occurring around tissue-level implants before prosthetic loading could be compensated by adapting apico-coronal positioning to mucosal thickness.

METHODS

Patients requiring placement of one single implant in the posterior mandible were treated with tissue-level implants with a 3-mm high transmucosal machined component and moderately rough implant body. Based upon vertical mucosal thickness measured after buccal flap reflection, implants were placed with the treated part: (group 1) 2 mm below crestal level in presence of thin mucosa (<2.5 mm); (group 2) 1 mm below the crestal level in presence of medium mucosa (2.5-3.5 mm); (group 3) at equicrestal level in presence of thick mucosa (>3.5 mm).

RESULTS

Forty-nine implants, placed in 49 patients were included in final analysis (group 1: 18 implants; group 2: 16 implants; group 3: 15 implants). Mean marginal bone resorption after 5 months of healing was 0.66 ± 0.49 mm, 0.32 ± 0.41 mm, and 0.22 ± 0.52 mm in groups 1, 2, and 3, respectively. Inter-group analysis highlighted significant differences between the three groups after ANOVA test (p = 0.025). However, adaptation of apico-coronal implant positioning in relation to mucosal thickness, allowed to avoid early exposure of the treated surface in 100%, 93.7%, and 53.3% of the implants in groups 1, 2, and 3, respectively.

CONCLUSION

During supracrestal tissue height formation, tissue-level implants inserted adapting apico-coronal positioning in relation to mucosal thickness exhibited greater marginal bone resorption at sites with thin mucosa than at sites with medium or thick mucosa. However, anticipating supracrestal tissue height establishment by adapting apico-coronal implant positioning in relation to mucosal thickness may effectively prevent unwanted exposure of treated implant surface.

Scanning Electron Microscopy Analyses of Dental Implant Abutments Debonded from Monolithic Zirconia Restorations Using Heat Treatment: An In Vitro Study

Aim: The aim of this in vitro study is to present a debonding protocol developed to remove a screw-retained, monolithic, zirconia restoration from its titanium-base abutment, and to microscopically evaluate the abutment integrity at both the prosthetic and connection levels. Materials and Methods: A total of 30 samples were tested. Each sample consisted of a monolithic zirconia restoration bonded on a titanium link abutment. Five different shapes were designed and fabricated. Randomly, one-third of the Ti-link abutments were subjected to an anodizing process. Then, all the zirconia samples were bonded to the Ti-link abutments according to a pre-established protocol. Forty-eight hours later, the samples were debonded according to the experimental protocol. The outcomes were evaluated by a visual inspection with an optical microscope, scanning electron microscopy (SEM), and chemical composition analysis. Results: Thirty samples were collected and visually analyzed. Seven samples were randomly evaluated via scanning electron microscopy. In all the examinations, no relevant changes were reported. Chemical composition analysis also relieved no changes in the chemical structure of the titanium. Conclusions: The titanium-base abutments do not alter the structure and properties of the material, not creating phase changes or the birth of oxides such as to induce fragility. Further clinical studies with longer follow-up periods are needed to confirm these preliminary results.

Clinical and Laboratory Outcomes of Angled Screw Channel Implant Prostheses: A Systematic Review

The purpose of this systematic review was to evaluate the clinical and laboratory outcomes of angled screw channel (ASC) restorations and to summarize the influencing factors. An electronic search of the English language literature was performed in four databases and enriched by manual searches. Retrieved studies were screened against the predefined exclusion and inclusion criteria. Eight clinical and seven laboratory studies were eligible for the analysis. The risk of bias for included observational studies was performed using the Newcastle–Ottawa quality assessment scale. Laboratory studies quality assessment method was adapted from previous published systematic reviews. Two clinical studies focused on technical outcomes and the rest reported the biological outcomes of the ASC restorations. Out of the seven laboratory studies, two studies investigated the fracture resistance of ASC restorations, four studies evaluated the reverse torque value of the nonaxially tightened screws, and one study evaluated both variables. The present review revealed that while the performance of ASC restorations is promising in short-term clinical studies, the evidence of their long-term reliability is still lacking. The laboratory studies indicated comparable fracture resistance results of the ASC restorations with the straight screw channel restorations. In addition, factors, such as initial torque value, configuration of the screw driver, screw design, abutment system, and the angulation of screw channel, were shown to influence the screw resistance to loosening.

Comparison between Early Loaded Single Implants with Internal Conical Connection or Implants with Transmucosal Neck Design: A Non-Randomized Controlled Trial with 1-Year Clinical, Aesthetics, and Radiographic Evaluation

To evaluate the implant and prosthetic of two implants with different surfaces and neck design. Enrolled patients received bone level, 12° conical connection implants (Nobel Parallel, Nobel Biocare; NOBEL group) with anodized surface (TiUnite) and roughness of 1.35 μm, or transmucosal implant system (Prama, Sweden and Martina; PRAMA group) with convergent collar, ZIrTi surface, and roughness 1.4–1.7 μm. Both implants were made of pure grade IV titanium, with similar diameter and length, chosen according to the dentistry department availability and patient’s request. After early prosthesis delivery, patients were filled for at least one year. Outcome measures were: implant and prosthetic survival and success rates, physiological marginal bone remodeling, periodontal parameters and pink esthetic score (PES). Results: Fifteen patients were allocated and treated in each group. At the one-year follow-up, three patients dropped out, one in the NOBEL group and two in the PRAMA group. During the entire time of investigation, all implants survived and the prostheses were successful. No statistically significant differences were found in term of marginal bone loss, periodontal parameters, and aesthetics (p > 0.05). Conclusion: With the limitations of the present study, both implant systems showed successful clinical results. Finally, many other clinical and surgical variables may influenced marginal bone levels, implant survival, and periodontal parameters. More homogenous clinical trials with larger samples are needed to confirm these preliminary conclusions.

Five-Year Prospective Study on Implant Failure and Marginal Bone Remodeling Expected Using Bone Level Implants with Sandblasted/Acid-Etched Surface and Conical Connection

OBJECTIVE

 The purpose of the present prospective, case-series study was to report implant survival rate and marginal bone remodeling expected 5 years after loading using dental implants placed in daily practice.

MATERIALS AND METHODS

 This research was designed as an open-cohort, prospective, case-series evaluation. Any partially or completely edentulous patient, scheduled to receive at least one bone level implant, was considered eligible for this study. Primary outcome measurements were: implant and prosthetic cumulative survival rate and any complications experienced up to the 5-year follow-up. Secondary outcome measures were: thickness of gingival biotype, implant insertion torque, implant stability quotient, and marginal bone loss (MBL).

RESULTS

 Ninety consecutive patients (34 males and 56 females, aged between 24 and 81 years old [mean: 53.2 ± 15.4]) with 243 inserted implants were followed for at least 5 years after loading (mean: 65.4 ± 3.1 months; range from 60 to 72). At the 1-year follow-up, no drop-outs were recorded, but 17 patients (18.9%) with 18 restorations (12.6%) delivered on 34 implants (14%) were lost at the 5-year examination. At the 5-year follow-up examination, six implants lost osseointegration (97.5%). In the same period, four prostheses failed (97.2%). Five complications were reported in five different patients (prosthetic success rate was 96.5%, at patient level). Five years after loading, the mean MBL was 0.41 ± 0.30 mm. The difference from the 1-year data was 0.04 ± 0.19 mm. A statistically significant higher MBL was found for smokers, and patients with thin gingival biotype. The mean implant insertion torque was 42.9 ± 4.8 Ncm (range from 15 to 45 Ncm). Two-hundred and three implants (83.5%) were inserted with an insertion torque ≥35 and ≤45 Ncm.

CONCLUSIONS

 High implant survival and success rate could be expected with stable marginal bone remodeling up to 5 years after loading. Smoking and thin tissue biotype were the most important variabilities associated with higher MBL. Further research studies are needed to confirm these results.

Esthetic And Functional Integration Of Soft Tissue Around Dental Implants: Thickness, Width, Stability

The long-term Functional success of the implant treatment depends on the stability of the crestal bone tissue around the implant platform. The Esthetic result is achieved by an adequate soft tissue in the peri-implant zone. Furthermore, the soft tissue creates the buffer area that ensures the mechanical and biological protection of the underlying bone. Therefore, it is necessary to maintain for a long term, not only the implant osseointegration but also the integration of the soft tissue around the Sub and Supra-structure of the restoration. In order to create the protective soft tissue area, it is necessary to ensure three criteria. This treatment approach will be defined as the TWS - Soft Tissue Management : T for Thickness , W for Width, and S for Stability . The purpose of this article is to present with clinical cases, the detailed description of each criteria. There are many ways to achieve the two first criteria and they are well described in the literature. Achieving the third criteria of the Stability become possible only in the last years since the development of the digital technology and its implementation into the dental practice. A one time abutment and the creation of peri- implant mucosal thickness with an optimal amount of the attached keratinized gingiva above and around the implant platform, for muco-gingival integration of the system, are therefore a prerequisite for functional and esthetic result. The article presents the possibility for the clinicians to use in their daily practice this new clinical approach of TWS - Soft Tissue Management.

One-Abutment One-Time Effect on Peri-Implant Marginal Bone: A Prospective, Controlled, Randomized, Double-Blind Study

Objective: To evaluate the peri-implant hard tissue change at 6 and 12 months after implant placement between definitive abutment placed at the same time of implant surgery, never removing it, and healing abutment disconnected and reconnected three times until the placement of the final rehabilitation. Material and methods: Each partial edentulous patient could receive between 1 and 4 platform-switched implants in the posterior regions. If the implants had primary stability—implant stability quotient (ISQ) equal to or greater than 50, they were randomized to the test group with the abutment inserted at the same time of implant placement (DA) or to the control group, receiving a healing abutment (PA). At 6 and 12 months after surgery, data related with vertical bone level changes (primary outcome) and other clinical parameters (implant mobility, bleeding on probing, probing depth, plaque index) were assessed. Results: 53 implants were included in the trial and completed 12 months follow-up (overall survival rate: 100%). All implants achieved primary stability, with an average ISQ value of 80.9 on the day of surgery. From surgery to 6 months, the mean bone loss was 0.14 ± 0.18 mm for the DA group and 0.23 ± 0.29 mm for the PA group, without statistical significance difference. Between 6 and 12 months, the mean bone loss was 0.14 ± 0.21 mm for the DA group and 0.21 ± 0.27 mm for the PA group, also without statistical significance between the two groups. There were no statistically significant differences (p = 0.330) in total bone loss after 12 months between the control and the study groups. Conclusions: The one abutment one time protocol has at least an equivalent effect on the peri-implant bone level changes when compared with the use of healing abutments that are disconnected and reconnected at least three times.

Cross-sectional evaluation of clinical and immunological parameters at partially microgrooved vs machined abutments in humans

OBJECTIVE

The objective of the present study was to examine the clinical and immunological parameters in samples collected from the peri-implant crevicular fluid (PICF) of machined titanium (M) abutments compared to titanium abutments with a laser-microtextured surface (LMS) on dental implants.

MATERIAL AND METHODS

A total of 40 patients with one titanium implant, half of them (n=20) provided with a M abutment (control group) and the other half (n=20) with LMS abutments (test group), were included in the study. Clinical parameters pocket probing depth (PD), full-mouth plaque score (FMPS), radiographic bone loss (RBL), clinical attachment level (CAL), mucosal recession (MR), bleeding on probing (BOP), and width of keratinized mucosa (KM) were evaluated. The peri-implant sulcus fluid was analyzed for cytokines IL-1α, IL-1β, IL-6, IL-8, and IL-10 via flow cytometry.

RESULTS

Clinical evaluation demonstrated no significant difference of PD (mean LMS = 3.50 mm/SD 0.95 mm vs mean M = 3.45 mm/SD 0.76 mm (p=0.855)), MR (mean LMS = 0.30 mm/SD 0.57 mm vs mean M = 0.35 mm/SD 0.67 mm (p=0.801)), CAL (mean LMS = 3.60 mm/SD 1.14 mm vs mean M = 3.55 mm/SD 0.89 mm (p=0.878)), and KM (mean LMS = 2.03 mm/SD 1.08 mm vs mean M = 2.13 mm/SD 0.92 mm (p=0.754)) between LMS and M abutments. LMS abutments showed less BOP than M abutments (26.7% vs 30.8%), but statistically not significant (p = 0.2235). Radiographic bone loss (mean LMS = 0.22 mm/SD 0.44 mm vs mean M = 0.59 mm/SD 0.49 mm) was reduced in the test group in comparison with the control group (p=0.016). In the collected PICF, the levels of pro-inflammatory cytokines IL-1α (median LMS = 180.8 pg/ml vs M = 200.9 pg/ml (p=0.968)) and IL-1β (median LMS = 60.43 pg/ml vs M = 83.11 pg/ml (p=0.4777)) were lower, and the levels of IL-6 (median LMS = 180.8 pg/ml vs M = 200.9 pg/ml (p<0.0001)) were significantly lower in the test group. In contrast, the levels of IL-8 (median LMS = 255.7 pg/ml vs M = 178.7 pg/ml (p=0.3306)) were higher in the test group, though not significantly. The levels of anti-inflammatory IL-10 were significantly increased in the test group (LMS median = 0.555 pg/ml vs M median = 0.465 pg/ml (p=0.0365)). IL-1β showed a significant correlation to radiologic bone loss (p=0.0024). The other variables IL-1α, IL-6, IL-8, and IL-10 had no significant correlation to radiological bone loss.

CONCLUSION

Within the limitations of this study, titanium implants provided with laser-microtextured surface abutments seem to demonstrate less pro-inflammatory and more anti-inflammatory activity and to show reduced radiographic bone loss compared to machined titanium abutments.

CLINICAL RELEVANCE

The use of laser-microtextured surface abutments might have the potential to support peri-implant tissue health.

Clinical Performance of a Novel Two-Piece Abutment Concept: Results from a Prospective Study with a 1-Year Follow-Up

Development of a stable and healthy soft-tissue barrier around dental implants is key to long-term success of implant-supported prostheses. The novel two-piece abutment concept shifts the prosthetic interface to the soft-tissue level to protect bone interface/connective tissue during the healing phase and restorative procedures. This prospective study included 72 patients treated with 106 implants to support a single-tooth or a three-unit bridge restored with two-piece abutments. The evaluation included marginal bone level change (MBLC), implant and prosthetic survival, soft-tissue health including keratinized mucosa height and mucosal margin position, patient quality of life (QoL) and satisfaction, and clinician satisfaction and ease-of-use rating of the concept. Mean MBLC from implant placement to 1 year was -0.36 ± 1.26 mm (n = 89), the 1-year implant and prosthetic survival rates were 97.1 and 96.7%, respectively, while keratinized mucosa height increased from 2.9 ± 1.2 mm at prosthetic delivery to 3.2 ± 1.3 mm, and mucosal margin migrated coronally by 0.49 ± 0.61 mm by 1 year. Patient satisfaction and QoL were high. Clinicians were satisfied with the esthetic and functional results and rated the concept as easy to use. In conclusion, the novel two-piece abutment concept promotes good peri-implant tissue health, while providing an easy-to-use workflow and high treatment satisfaction to both patients and clinicians.

One-Piece Titanium Implants: Retrospective Case Series

Purpose

One-piece titanium implants are not routinely used for reconstruction after tooth loss. Several limitations seemed to be apparent although the concept provides a straightforward approach for different clinical situations. A clinical documentation of five prosthetic restorations with one-piece titanium implants serving as a relevant treatment option in dental surgery is pursued. We demonstrate the feasibility and benefits of one-piece titanium implants for fixed dental prosthesis. Detailed descriptions of the technical features and the surgical approach by means of clinical cases are given. The prosthetic workflow when working with one-piece titanium implants is depicted in detail as well as examples for implant-supported tooth replacement in the posterior region and the esthetic zone. Conditions of applications regarding different timing of implant placement using the system and its limitations are discussed.

Results

Clinical cases with a follow-up period of up to 10 years are presented to prove the long-term success of one-piece titanium implants in terms of bone and soft-tissue stability respecting the biological criteria for periodontal health.

Conclusions

One-piece titanium implants represent a reliable treatment method for single-tooth replacements. Clinical success with long-time bone stability around the implantation site can be achieved. Taken into account the requirements for periodontal tissue stability, uneventful healing without extensive tissue loss is demonstrated by means of clinical cases presenting patients with periodontitis.

Tissue-level versus bone-level single implants in the anterior area rehabilitated with feather-edge crowns on conical implant abutments: An up to 5-year retrospective study

STATEMENT OF PROBLEM

Limited information is available on the differences between tissue-level implants with an ultrathin threaded microsurface conical transmucosal portion and bone-level implants rehabilitated with conical custom abutments.

PURPOSE

The purpose of this retrospective study was to assess the outcomes of crowns designed as per the biologically oriented preparation technique (BOPT) cemented on conical titanium abutments on tissue-level and bone-level implants.

MATERIAL AND METHODS

Patients consecutively rehabilitated with a delayed loading protocol with anterior implant-supported single crowns with a feather-edge margin, in function for at least 4 years, were recruited and divided into 2 groups based on the implant type they had received: tissue-level implants with a conical transmucosal portion or bone-level implants rehabilitated with a conical abutment by following the platform switching concept. Bone resorption, pink esthetic score (PES), and white esthetic score (WES) were collected and analyzed. The nonparametric Mann-Whitney test was performed to analyze all parameters (α=.05 for all tests).

RESULTS

A total of 43 participants (48 implants) were included in the present study. The mean follow-up period was 4.5 years (range 52-64 months). A statistically significant difference (P=.004) was found in the mean ±standard deviation bone resorption between tissue-level implants (0.38 ±0.46 mm) and bone-level implants (0.83 ±0.58 mm). Higher values for both PES and WES were obtained in the tissue-level implant group.

CONCLUSIONS

Within the limitations of the present retrospective study, tissue-level implants with a conical transmucosal portion seem to provide a suitable alternative to bone-level implants in the anterior area.

1-Year Evaluation of OT Bridge Abutments for Immediately Loaded Maxillary Fixed Restorations: A Multicenter Study

Objective  Preliminary data on survival and success rates of immediately loaded, maxillary, screw-retained, implant-supported, fixed restorations delivered on narrow and low-profile OT Equator abutments (OT Bridge, Rhein’83) were evaluated.

Materials and Methods  This retrospective study evaluated data collected from patients rehabilitated with OT Bridge prosthetic concept between November 2017 and February 2019 in six different centers. Outcome measures were implant and prosthetic survival rates, biological and technical complications, marginal bone loss (MBL), oral health impact profile (OHIP), bleeding on probing, and plaque index.

Results  A total of 76 implants were inserted in 14 patients. Patients were followed for a mean period of 15.8 months (range = 12–24). All the patients receive OT Equator (Rhein'83) as intermediate abutments. One year after loading, one implant failed (1.3%). None of the prosthesis failed. One prosthetic complication was experienced in one patient. Three out of 76 implants were connected to the prosthetic framework using only the Seeger system, without screw. Difference in OHIP values was statistically significant (71.9 ± 8.5; p = 0.000). One year after loading, MBL was 0.21 ± 0.11 mm and p- value was 0.000. One year after loading, 8.7% of the examined implant sites present positive bleeding on probing, while 6.4% of the implant sites presented plaque.

Conclusion  The OT Equator abutments (Rhein'83) showed successful results when used to support maxillary fixed dental prosthesis delivered on four to six implants. High implant and prosthetic survival rates, very low complications, high patient satisfaction, and good biological parameters, including only 0.2 mm of bone remodeling were experienced one year after function. Further studies are needed to confirm these preliminary results.

Three-Year Retrospective Comparative Study between Implants with Same Body-Design but Different Crest Module Configurations

Crest module can be defined as the portion of a two-piece implant designed to retain the prosthetic components and to allows the maintenance of the peri-implant tissues in the transition zone.

AIM

To evaluate the three-year after loading clinical and radiographic data, collected from patients that received a prosthetic rehabilitation on conical connection implants with partial machined collar (PMC; CC Group) and same body-designed implants, with flat-to-flat connection and groovy neck design (FC Group).

MATERIALS AND METHODS

A retrospective chart review of previously collected data, including documents, radiographs, and pictures of patients who received at least one implant-supported restoration on NobelReplace CC PMC or NobelReplace Tapered Groovy implants was performed. Patients with at least three years of follow-up after final loading were considered for this study. Outcomes measures were implant and prosthesis failures, any biological or technical complications, marginal bone loss.

RESULTS

Eight-two patients (44 women, 38 men; average age 55.6) with 152 implants were selected and divided in two groups with 77 (CC group) and 75 (FC group), respectively. Three years after final loading, one implant in CC group failed (98.7% survival rate), while no implants failed in FC group (100% survival rate). One restoration failed in CC group (98.7% survival rate) with no restoration failing in the FC one (100% survival rate). Differences were not statistically significant (p = 1.0). Three years after final loading, mean marginal bone loss was 0.22 ± 0.06 mm (95% CI 0.2-0.24) in CC group and 0.62 ± 0.30 mm (95% CI 0.52-0.72) in FC group. The difference was statistically significant (0.40 ± 0.13 mm; 95% CI 0.3-0.5; p = 0.003).

CONCLUSION

with the limitation of this retrospective comparative study, implants with conical connection and partial machined collar seem to achieve a trend of superior outcomes if compared with implants with flat connection and groovy collar design.

A One-Year, Multicenter, Retrospective Evaluation of Narrow and Low-Profile Abutments Used to Rehabilitate Complete Edentulous Lower Arches: The OT Bridge Concept

Purpose: To evaluate preliminary data on survival and success rates of immediately loaded, screw-retained, restorations delivered on lower arches using narrow and low-profile OT Equator abutments. Methods: This retrospective study analyzed data of patients rehabilitated with OT Bridge (fixed prosthetic system built on OT Equator) prosthetic concept from November 2017 to February 2019 in five different centers. Outcome measures were implant and prosthetic survival rates, biological and technical complications, marginal bone loss (MBL), oral health impact profile (OHIP), bleeding on probing, and plaque index. Results: A total of 60 implants were inserted in 12 patients. Patients were followed for a mean period of 15.8 months (range 12–24). All the patients received OT Equator as intermediate abutments. Four out of 60 implants were connected to the prosthetic framework using only the Seeger system, without a screw. One year after loading, three implants failed (implant survival rate of 95.0%) in two patients. No prosthesis failed and no major biological and technical complications were experienced. One year after initial loading, the marginal bone level was 0.32 ± 0.2 mm. The OHIP before treatment was 87.7 ± 6.0. One year after treatment, OHIP was 23.6 ± 1.2. The difference was statistically significant (64.1 ± 7.2; p = 0.0000). One year after loading, 8.9% of the examined implant sites present positive bleeding on probing, while 5.8% of the implant sites presented plaque. Conclusions: The OT Equator abutments showed successful results when used to support mandible fixed dental prosthesis delivered on 4–6 implants. Whole prosthetic survival and success rates, high patient satisfaction, and good biological parameters were experienced one year after function. Further prospective studies are needed to confirm these preliminary results.

Multivariate analysis of the influence of peri-implant clinical parameters and local factors on radiographic bone loss in the posterior maxilla: a retrospective study on 277 dental implants

OBJECTIVES

The aim of the present study was to investigate whether peri-implant clinical parameters (modified plaque index (mPI), bleeding and/or suppuration on probing (B/SOP)) and local factors (type of prostheses, screw emergence, platform diameter, and abutment angulation) might contribute to the development of additional bone loss and peri-implantitis around dental implants.

MATERIALS AND METHODS

Two hundred seventy-seven external hex connection implants placed in the posterior maxilla of 124 patients were retrospectively evaluated. They were divided into two groups: physiologic bone loss < 2 mm (PBL) or additional bone loss ≥ 2 mm (ABL). GEE logistic regression was applied to evaluate the influence of type of prostheses (implant-supported single crown (ISSC), fixed partial denture (ISFPD), and full denture (ISFD)) and clinical parameters (mPI and S/BOP) on bone loss.

RESULTS

Among the 277 implants, 159 (57.4%) presented PBL and 118 (42.6%) presented ABL. Within the ABL group, 20.6% implants were diagnosed with peri-implantitis. mPI significantly correlated with the type of prosthesis and the highest value of mPI (index = 3) was observed in ISFD (23.8%). Moreover, peri-implantitis was more frequently associated with ISFD (32.79%) than ISSC and ISFDP (13.79% and 13.48, respectively) CONCLUSIONS: ISFD in the posterior maxilla presented high rates of ABL and showed a higher prevalence of peri-implantitis. None of the local factors seemed to contribute to the development of these conditions. Further investigations are needed to prospectively support the results of the present study.

CLINICAL RELEVANCE

Patients rehabilitated with ISFD should be carefully monitored and have more frequent maintenance visits to prevent or control peri-implant bone loss.

The effect of a 2-mm inter-implant distance on esthetic outcomes in immediately non-occlusally loaded platform shifted implants in healed ridges: 12-month results of a randomized clinical trial

BACKGROUND

Three millimeter is considered as the minimum distance to obtain soft and bone tissue stability in case of adjacent implants. The possibility to preserve peri-implant bone level using a platform switching connection has questioned this concept.

PURPOSE

The study evaluates soft tissue maintenance and marginal bone stability around implants, placed at 2 or 3 mm of distance.

MATERIALS AND METHODS

Thirty patients received two immediately loaded implants either at 2-mm (test) or at 3-mm (control) of distance in the premolar area. Soft tissue esthetics (papilla height and fill, keratinized tissue, recession) and radiographic peri-implant bone level changes were measured at 3, 6, and 12 months.

RESULTS

No significant differences between the two groups were detected neither for all soft tissue esthetic outcomes nor for bone level modifications up to 12 months.

CONCLUSION

The results suggested that up to 12 months post-loading, both 2- and 3-mm inter-distance platform-switched implants in healed site, supported adequate esthetic outcomes and peri-implant bone stability.

Is It Possible to Monitor Implant Stability on a Prosthetic Abutment? An In Vitro Resonance Frequency Analysis

In order to apply the “one-abutment–one-time” concept, we evaluated the possibility of measuring resonance frequency analysis (RFA) on the abutment. This trial aimed to compare the Implant Stability Quotient (ISQ) values obtained by the Penguin^RFA when screwing the transducer onto the implant or onto abutments with different heights and angulations. Eighty implants (VEGA^®, Klockner Implant System, SOADCO, Les Escaldes, Andorra) were inserted into fresh bovine ribs. The groups were composed of 20 implants, 12 mm in length, with two diameters (3.5 and 4 mm). Five different abutments for screwed retained restorations (Permanent^®) were placed as follows: straight with 1, 2, and 3 mm heights, and angulated at 18° with 2 and 3 mm heights. The mean value of the ISQ measured directly on the implant was 75.72 ± 4.37. The mean value of the ISQ registered over straight abutments was 79.5 ± 8.50, 76.12 ± 6.63, and 71.42 ± 6.86 for 1, 2, and 3 mm height abutments. The mean ISQ over angled abutments of 2 and 3 mm heights were 68.74 ± 4.68 and 64.51 ± 4.53 respectively. The present study demonstrates that, when the ISQ is registered over the straight abutments of 2 and 3 mm heights, the values decrease, and values are lower for angled, 3 mm height abutments.

Effect of 5 Popular Disinfection Methods on Microflora of Laboratory: Customized Implant Abutments

PURPOSE

To compare the efficacy of 5 different decontamination methods of titanium abutments and to assess their possible effects on surface roughness of titanium.

MATERIALS AND METHODS

Micrococcus luteus, Acinetobacter baumannii, Enterococcus faecalis, and Candida albicans were cocultured to form a multispecies biofilm on 18 titanium discs. In another group, Bacillus subtilis, a spore-forming species, was cultivated on another set of 18 titanium discs. Each group was further divided into 5 test groups: high-pressure steam cleaning (4 Mpa, 5 seconds), NaOCl (1% active chlorine, 5 minutes), H2O2 (3%, 5 minutes), GaAlAs laser (810 nm, CW, 1 W, 400-μm fiber, 1-mm distance, 1 minute), Er:YAG laser (2940 nm, pulse mode, 100 mJ, 10 Hz, 230-μm noncontact handpiece, 4-mm distance, 50/50% air/water, 1 minute), and a control group of no treatment. After each decontamination procedure, the remaining microbial load was reported as colony-forming unit/disc. To evaluate the effect of each treatment on titanium discs, surface roughness parameters including Sa, Sq, Ssk, Sku, Sal, and Sdr were measured at 6 points of each disc using an atomic force microscope.

RESULTS

Complete disinfection was achieved using high-pressure steam, NaOCl, H2O2, and Er:YAG laser. GaAlAs laser was able to reduce microbial count over 90%. Sa and Sq parameters were only increased significantly in diluted NaOCl group in comparison with control group, whereas Sdr was increased significantly in both absolute and diluted NaOCl groups.

CONCLUSION

All the methods could decontaminate machined titanium surfaces, although complete microbial elimination was not achieved by diode laser. None of the treatments altered surface roughness significantly, except for sodium hypochlorite (NaOCl).

Biological and mechanical complications of angulated abutments connected to fixed dental prostheses: A systematic review with meta-analysis

OBJECTIVES

To evaluate the biological and mechanical complications of angulated abutments on full-arch and partial jaw rehabilitations with a follow-up for at least 1 year.

METHODS

Electronic search was carried out in MEDLINE, EMBASE and Web of Science. Studies published between January 2000 and January 2019 were included. The quality of the included studies was assessed. The data extraction was focused on implant loss, marginal bone loss and mechanical complications, and meta-analyses were performed for marginal bone loss, mechanical complications and implant failure.

RESULTS

Nine studies, three prospective and six retrospective cohort studies were included. They reported on 797 patients that received 4127 implants. The total number of abutments was 4079 of which 1673 were angulated, and 2406 were straight. All abutments were prefabricated. Angulated abutments were associated with increased implant failure rates (two studies; RR = 7.30; 95% CI = 2.79-19.08) and an effect that was both statistically significant (P < .001) and clinically relevant. Three studies reported differentiated data for mechanical and technical complications at 1 year of follow-up, being mostly related to the retention screw while screw fracture. Angulated abutments were associated with a statistically significant increase in MBL 1 year after insertion compared to straight abutments (three studies; MD = 0.08 mm; 95% CI = 0.01-0.14 mm; P = .02), which might be, however, clinically negligible.

CONCLUSIONS

The prosthetic complications such as screw loosening and abutment loosening were frequent. After 1 year of follow-up, implants supporting angulated abutments yielded significantly more marginal bone loss than those supporting straight abutments.

Patient-centered rehabilitation of single, partial, and complete edentulism with cemented- or screw-retained fixed dental prosthesis: The First Osstem Advanced Dental Implant Research and Education Center Consensus Conference 2017

The aim of this consensus conference was to provide clinical guidelines, based on the available evidence and on the author's daily practice and experience, for general dentistry and dental practitioners to allow them to delivery long-term successful restorations. Three groups of expert clinicians and dental technicians were invited to evaluate all of the scientific literature from 1967 up to March 2017 to identify relevant studies on assigned topics and to prepare in advance narrative/systematic review, written according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, to fulfill the consensus statement criteria. The three topics assigned to the three groups were abutment/framework materials and customization (metal vs. metal-free restorations), abutment/framework protocols and designs, and abutment/framework retentions (cemented- vs. screw-retained implant-supported prostheses). All the expert clinicians presented their results, and the lectures were followed by discussions. No significant differences in clinical parameters (marginal bone loss, bleeding on probing, and pocket probing depth) between screw- or cemented-retained were found for single and multiple implant-supported restorations. There is moderate evidence that nonoriginal abutments provide worse mechanical behavior than originals and high evidence that different implant neck designs do not offer any clinical or radiographic advantage. All the participants agreed that it is desirable to connect and remove abutments as few times as possible. There is medium evidence that an adequate platform switching tends to enhance tissue volume and stability in the medium- and long-term follow-up. No statistically significant differences exist between metal and zirconia as a framework material. The authors discussed and all agreed that retrievability and patient's expectation (function and esthetics) should guide the choice of the most adequate technique, component, and material.

Is Peri-Implant Probing Causing Over-Diagnosis and Over-Treatment of Dental Implants?

Pocket probing depth (PPD) and bleeding on probing (BOP) measurements are useful indices for the assessment of periodontal conditions. The same periodontal indices are commonly recommended to evaluate the dental implant/tissue interface to identify sites with mucositis and peri-implantitis, which, if not treated, are anticipated to lead to implant failure. The aim of the present narrative review is to discuss the available literature on the effectiveness of probing at dental implants for identification of peri-implant pathology. There is substantial clinical evidence that PPD and BOP measurements are very poor indices of peri-implant tissue conditions and are questionable surrogate endpoints for implant failure. On the contrary, the literature suggests that frequent disturbance of the soft tissue barrier at implants may instead induce inflammation and bone resorption. Moreover, over-diagnosis and subsequent unnecessary treatment may lead to iatrogenic damage to the implant-tissue interface. Despite this, the recommendations from recent consensus meetings are still promoting the use of probing at dental implants. For evaluation of implants, for instance at annual check-ups, the present authors recommend a clinical examination that includes (i) a visual inspection of the peri-implant tissues for the assessment of oral hygiene and the detection of potential redness, swelling, (ii) palpation of the peri-implant tissues for assessment of the potential presence of swelling, bleeding, suppuration. In addition, (iii) radiography is recommended for the assessment of crestal bone level for comparison with previous radiographs to evaluate potential progressive bone loss even if there is a need for more scientific evidence of the true value of the first two clinical testing modes.

Digital Tissue Preservation Concept: A Workflow for Guided Immediate Implant Placement and Restoration

The digital workflow presented here allows for fabrication and placement of a definitive custom abutment at the time of tooth extraction and guided immediate implant placement, thus preserving soft tissue anatomy. Since abutment design was based on the shape of the original tooth, it represented a de facto emergence-analog that provided ideal soft tissue support. The approach of superposing and merging of custom abutment design data with data captured intraorally after abutment placement enabled a digital impression without gingival displacement and associated trauma. The generated data facilitated the fabrication of a precisely fitting restoration concurrent with the implant healing period.

Systematic review versus structured critical analysis

Objective: This analysis discusses common problems with systematic reviews (SRs) and presents a novel solution, the structured critical analysis (SCA) that can be incorporated into a SR or used as an alternative literature review design.Methods: A cross-sectional survey of current SRs related to interdisciplinary restorative dentistry was obtained by evaluating 100 current SRs for their self-reported methodological quality and its effect on scientific validity.Results: The preferred reporting items for systematic reviews and meta-analyses protocol (PRISMA) was used in 99/100 SRs, but only 8/100 reported a low risk of bias. High statistical heterogeneity precluding meta-analysis was found in 44/100 SRs. Only 94 paragraphs/100 SRs provided critical analysis.Discussion: Significant problems were found with current SRs that can compromise their reliability as the premier level of evidence for clinical science research. The reader must be aware of these deficiencies to correctly interpret the SR and cannot rely on the format alone.