The esthetic biological contour concept for implant restoration emergence profile design

The effect on the performance of a dynamic navigation system of superimposing a standard tessellation language (STL) file obtained with an intraoral scan on a cone beam computer tomograph (CBCT). An experimental in vitro study

OBJECTIVES

To compare the accuracy and operative time of implant placement using a dynamic computer assisted implant surgery (dCAIS) system based on a cone beam computer tomography (CBCT) image, with and without superimposing a standard tessellation language (STL) file of an intraoral scan of the patient.

METHODS

Ten identical resin models simulating an upper maxilla with posterior edentulism were assigned to two groups. In the CBCT+STL group, a CBCT file and an intraoral STL file were superimposed and used for registration; in the CBCT group, registration was performed using CBCT images. Six implants were placed in each model using the Navident® dynamic navigation system. Anatomy registration was performed by tracing fiducial points on the CBCT or STL image, depending on the group. Preoperative and postoperative CBCT images were overlaid to assess implant placement accuracy.

RESULTS

Sixty implants were analyzed (30 implants in each group). 3D platform deviation was significantly lower (mean difference (MD): 0.17 mm; 95 % confidence interval (CI): 0.01 to 0.23; P = 0.039) in the CBCT+STL group (mean: 0.71 mm; standard deviation (SD): 0.29) than in the CBCT group (mean: 0.88 mm; SD: 0.39). The remaining accuracy outcome variables (angular deviation MD: -0.01; platform lateral deviation MD: 0.08 mm; apex global MD: 0.01 mm; apex depth MD: 0.33 mm) and surgery time (MD: 3.383 min.) were similar in both groups (p > 0.05).

CONCLUSIONS

The introduction of an intraoral scan (STL) seems to reduce deviations slightly in dental implant placement with dCAIS systems. However, the clinical repercussion of this improvement is questionable.

CLINICAL SIGNIFICANCE

Superimposing an intraoral scan on the CBCT image does not seem to increase the accuracy of dCAIS systems but can be useful when radiographic artifacts are present.

Cone beam computed tomography assessment of maxillary anterior teeth cervix dimensions in healthy adults for optimal anatomic healing abutments

OBJECTIVES

The abutments produced with circular symmetry failed to accurately replicate the natural teeth's cervical shapes. The purpose of this study was to measure cervical cross-sections of maxillary anterior teeth using cone beam computed tomography (CBCT) images to design anatomic healing abutments.

MATERIALS AND METHODS

CBCT data of 61 patients were analyzed using Ez3D Plus software. Measurements were taken at the cemento-enamel junction (CEJ) and 1 mm coronal to CEJ for maxillary central incisors, lateral incisors, and canines. Various parameters, including area, perimeter, and eight line segments in the distal (a), disto-palatal (b), palatal (c), mesio-palatal (d), mesial (e), mesio-labial (f), labial (g), and disto-labial (h) directions, were used to describe dental neck contours. The ratios (f/b and h/d) were analyzed, and differences based on sex and dental arch morphology were explored.

RESULTS

Significant differences were found in area and perimeter between males and females, but not in f/b and h/d ratios. Differences in the f/b ratio were observed among dental arch morphologies for maxillary central incisors, lateral incisors, and canines.

CONCLUSIONS

CBCT measurements of cervical cross-sections provide more accurate data for designing anatomic healing abutments. The fabrication of anatomical healing abutments needs to consider the influence of gender on cervical size and to explore the potential effect of arch shape on cervical morphology.

CLINICAL SIGNIFICANCE

The novel method provides detailed measurements for the description of dental cervical contours for patients with bilateral homonymous teeth missing. The measurements of this study could be utilized to design more accurate anatomic healing abutments to create desired morphology of peri-implant soft tissue.

Esthetic Integration Area concept to improve the emergence profile of fixed restorations: A dental technique

A technique for obtaining the esthetic integration and optimal emergence profile of tooth-supported and implant-supported restorations is described. Using a computer-aided design software program, data captured with an intraoral scanner were used to establish the anatomic landmarks for determining the maximum buccal volume to which a restoration can be extended. This technique could be applicable to different types of fixed-dental prostheses treatments. Advantages of this technique include the establishment of periodontal-prosthetic criteria and the improvement of clinical and laboratory communication since the same guidelines for evaluating restorative space in the buccolingual direction of tooth preparations are used to avoid overcontoured restorations.

Digital workflow in the design of individualized emergence profiles of implant restorations based on the contralateral tooth

PURPOSE

To describe a novel digital design technique for creating an individualized emergence profile for implant restoration based on the contralateral tooth.

METHODS

Cone beam computed tomography (CBCT) data were used to accurately obtain a three-dimensional (3D) model of the contralateral tooth, which was mirror-flipped to design the emergence profile. The emergence profile was further divided into critical and subcritical areas; the critical area precisely replicated the mirror-flipped 3D model, whereas the subcritical area featured a slight concavity on the buccal side, flatness on the lingual side, and slight convexity on the mesial and distal surfaces. Subsequently, a milling machine was used to fabricate healing abutments with individualized emergence profiles. The design of the definitive restoration completely duplicated the emergence profile of the individualized healing abutment and was fabricated using a milling machine.

CONCLUSIONS

This technical procedure presents an alternative novel method for designing the emergence profiles of implant restorations, with the potential to improve esthetics and functions as well as to maintain the long-term stability of peri-implant soft and hard tissues.

Soft tissue management around dental implant in esthetic zone - the current concepts and novel techniques

It has been said, 'Bone sets the tone, but tissue is the issue.' In the field of implantology, while significant breakthroughs have been achieved in hard tissue regeneration, clinicians find it more challenging to handle soft tissue complications around dental implants. Successfully managing soft tissue around dental implants requires clinicians to have comprehensive knowledge of proper implant placement, prosthetic design and tissue management, and a high level of surgical skills for soft tissue augmentation and grafting. Autogenous gingival grafts can be utilized in various clinical situations, providing surgeons with great potential and freedom to enhance the quality and quantity of peri-implant soft tissue. Emerging trends, such as digital tools for treatment planning, minimally invasive surgical approaches, and innovative biomaterials, can also contribute to a more pleasing outcome. By elucidating these multifaceted considerations, this review will serve as a valuable resource for clinicians aiming to achieve functional and aesthetic excellence in implant-based oral rehabilitation.

A Novel Prehydrated Porcine-Derived Acellular Dermal Matrix: A Histological and Clinical Evaluation

It is well known that soft tissue quality and quantity around dental implants is of paramount importance for later peri-implant health. For this purpose, the clinical and histological outcomes of the peri-implant mucosa, following soft tissue augmentation for soft tissue improvement with a novel prehydrated porcine acellular dermal matrix graft (PPADMG) in conjunction with simultaneous implant placement, were evaluated in this case series. Twenty-two patients were included in the study. They underwent a late implant placement protocol combined with PPADMG for soft tissue augmentation. A punch biopsy was taken at the time of uncovery of the submerged healed implant after a mean of 157 days healing time. Supracrestal soft tissue height (STH) was measured at the time of implant placement and uncovery. All sites showed a clinical increase in STH. The histological structure of the biopsies resembled a similar structure as found in the healthy oral mucosa. No unexpected tissue reactions could be found. Within the limits of this clinical and histological study, it may be concluded that STH improvement with this novel porcine-derived acellular dermal matrix, in combination with simultaneous implant placement, is a viable option to create a peri-implant tissue thickness and stability.

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.

Perio-prosthodontic pontic site management, part II: Pontic site reconstruction strategies to enhance the esthetic and biological outcomes

OBJECTIVE

Ridge deformities are present in most patients after tooth extraction; these defects make the management of future implant and pontic sites challenging to deal with. The restorative team should be able to diagnose and treat these deformities to allow for successful outcomes. Many approaches have been described to reconstruct pontic sites, each with specific indications. This article describes the different approaches to reconstructing pontic sites and their indications to allow for a proper esthetic and biological environment for future restorations.

CLINICAL CONSIDERATIONS

Depending on the severity of the defect, location, and the esthetic necessity, pontic site enhancement can be done through different approaches, some requiring soft tissue grafting, hard tissue grafting, or both. Understanding the indications of the treatment options is essential to allow the clinician to make the right therapeutic decision and achieve the best possible perio-prosthodontic outcomes.

CONCLUSIONS

An adequate balance between the soft tissue and prosthetics is essential to achieve successful results on implant-supported or tooth-supported fixed dental prostheses (FDPs). Selecting the right approach to treat ridge deformities is necessary to increase treatment success, reduce over-treatment, and create a biologically sound environment for restorations.

CLINICAL SIGNIFICANCE

Pontic site enhancement through reconstructive surgery will allow for esthetically pleasing and biologically stable results, allowing restorations to emulate natural structures lost after tooth extraction.

Impact of immediate interim restoration on peri-implant tissues around immediately placed single dental implants in the esthetic region: A systematic review and meta-analysis

STATEMENT OF PROBLEM

Immediate implant placement with an immediate interim restoration is a well-established protocol. Nevertheless, a consensus regarding the impact of immediate interim restoration on peri-implant tissues around single dental implants is lacking.

PURPOSE

The purpose of this systematic review and meta-analysis was to address the research question: "Does the placement of an immediate interim restoration influence the mid-facial mucosal (MFM) marginal and interdental papilla (IDP) levels around single dental implants placed in the anterior esthetic region by using an immediate implant placement protocol?"

MATERIAL AND METHODS

A comprehensive literature search was made in the Medline/PubMed, Scopus, Cochrane, and Science Direct electronic databases for articles published in English evaluating the impact of immediate interim restoration on peri-implant tissues around single dental implants in the anterior esthetic region. The primary outcomes assessed were changes in the MFM marginal and IDP levels. Additional outcomes were marginal bone (MB) loss, esthetic outcomes involving the pink and white esthetic scores (PES and WES), implant survival rates, and patient reported outcome measures (PROMs). The risk of bias assessment was performed by using the RoB 2 tool for randomized trials and the Newcastle-Ottawa scale for nonrandomized studies. Meta-analysis was performed by using random and fixed effects model (α=.05) in the RevMan software program.

RESULTS

Sixteen studies were included that analyzed 836 single dental implants involving 823 patients. The meta-analysis showed no significant differences in implants with and without interim restoration in terms of MFM marginal level (MD=0.01; 95% CI=-1.23 to 1.25; P=.98), mesial IDP level (MD=0.12; 95% CI=-0.23 to 0.47; P=.50), distal IDP level (MD=0.20; 95% CI=-0.40 to 0.79; P=.52), and MB loss (MD=0.01; 95% CI=-0.42 to 0.43; P=.97). The systematic analysis for survival rates determined no notable difference in implants with or without an interim restoration. However, the esthetic outcomes and PROMs substantially improved with immediate interim restorations. The RoB 2 tool showed a moderate to low risk of bias, and the Newcastle-Ottawa scale indicated high-quality studies.

CONCLUSIONS

After a 12-month follow-up, immediate interim restoration had no significant impact on peri-implant soft (MFM marginal and IDP levels) and hard tissues (MB loss) around immediately placed single dental implants. Nevertheless, additional well-designed and well-implemented clinical trials with long-term follow-up periods are needed to provide more precise evidence-based recommendations.

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.

Translucent monolithic zirconia titanium-supported FP1 full-arch prosthesis: A novel proof of concept to address esthetic, functional, and biologic challenges

OBJECTIVE

Despite the wide clinical use of translucent zirconia for full-arch implant prostheses, reduced flexural strength and fracture toughness compared with high-strength opaque zirconia needs to be addressed. A novel proof of concept for FP1 full-arch prosthesis featured by translucent monolithic zirconia and titanium framework was presented.

CLINICAL CONSIDERATIONS

Computer-guided implant planning and surgery were executed and digitally designed FP1 temporary prosthesis prefabricated. Implant and prosthetic placement were achieved with a set of three-dimensional (3D)-printed templates. Implants were immediately loaded. After 4 months intraoral optical scan was taken to record implant coordinates, soft tissue anatomy, and temporary FP1 prosthesis. A novel digital workflow was used to design and mill overlaying translucent zirconia and anatomically shaped titanium framework with a scalloped soft-tissue interface. Final FP1 prosthesis was assembled cementing zirconia jacket on titanium counterpart.

CONCLUSIONS

Translucent zirconia supported by titanium framework can address esthetic and mechanical requirements of FP1 full-arch prosthesis, minimizing risk of fracture and providing a rigid and passive joint with supporting implants. The smooth and highly polished titanium surface with an anatomic design, tightly matching scalloped soft tissue interface, can limit food impaction, air and saliva leakage and contribute to overall biologic integration of FP1 full-arch prosthesis.

CLINICAL SIGNIFICANCE

Translucent monolithic zirconia featured with anatomically shaped titanium framework with scalloped transmucosal part, combining a pleasant esthetic outcome with increased flexural strength and fracture toughness, may be indicated to increase the clinical performance of FP1 full-arch prosthesis.

Avoiding errors and complications related to immediate implant placement in the esthetic area with a mucogingival approach

Immediate implant placement is considered the treatment of choice for single tooth replacement in the esthetic area. However, this treatment is associated with several critical drawbacks related to the inadequate assessment/management of the soft and hard peri-implant tissues and their subsequent remodeling, resulting in peri-implant soft-tissue defects that can lead to impaired esthetic outcomes in time. We describe in detail how the mucogingival approach to immediate implant placement ensures a standard result regardless of the baseline soft-hard tissue situation. Fully guided implant placement guarantees an adequate three-dimensional implant placement, the flap design makes it possible to perform bone augmentation with complete visibility of the area being treated, allows soft tissue augmentation with proper fixation of the connective tissue graft, and the placement of an immediate provisional ensures stabilization of the peri-implant tissues throughout the healing period.

Outcomes of bio-esthetic single implant-supported restorations after peri-implant soft tissue conditioning with two prosthetic techniques: A 1-year randomized clinical trial

STATEMENT OF PROBLEM

Providing a definitive restoration with an emergence profile matching that of the contralateral or extracted tooth should result in an esthetic peri-implant soft tissue contour. Whether a custom healing abutment improves the outcome of a bio-copied definitive restoration compared with a stock abutment is unclear.

PURPOSE

The purpose of this 1-year randomized clinical trial was to evaluate the peri-implant soft and hard tissues related to bio-esthetic single implant-supported restorations having a contralateral tooth-matching restorative emergence profile after peri-implant soft tissue conditioning with either custom or stock healing abutment for patients indicated for immediate implant placement.

MATERIAL AND METHODS

Twenty-four participants indicated for immediate implant placement in the maxillary esthetic zone received bio-esthetic single implant-supported restorations after peri-implant soft tissue conditioning with either a custom healing abutment (n=12) or a stock healing abutment (n=12). The pink and white esthetic score (PES-WES) was evaluated 6 and 12 months after implant placement. Peri-implant bone changes were measured with cone beam computed tomography (CBCT) scans at the same intervals.

RESULTS

The PES-WES showed significant difference between the 2 groups at 6 and 12 months. The CBCT scans did not show significant difference between the 2 groups.

CONCLUSIONS

The use of the bio-esthetic concept for immediate single implant placement achieved successful esthetic restorations after conditioning the peri-implant tissues using either custom or stock healing abutments. However, the use of custom healing abutments was associated with higher PES-WES values in comparison with the use of stock healing abutments.

Implant prosthodontic design as a predisposing or precipitating factor for peri-implant disease: A review

Over the past decade, emerging evidence indicates a strong relationship between prosthetic design and peri-implant tissue health. The objective of this narrative review was to evaluate the evidence for the corresponding implant prosthodontic design factors on the risk to peri-implant tissue health. One of the most important factors to achieve an acceptable implant restorative design is the ideal implant position. Malpositioned implants often result in a restorative emergence profile at the implant-abutment junction that can restrict the access for patients to perform adequate oral hygiene. Inadequate cleansability and poor oral hygiene has been reported as a precipitating factors to induce the peri-implant mucositis and peri-implantitis and are influenced by restorative contours. The implant-abutment connection, restorative material selection and restoration design are also reported in the literature as having the potential to influence peri-implant sort tissue health.

Application of computer-aided design and 3D-printed template for accurate bone augmentation in the aesthetic region of anterior teeth

PURPOSE

To explore the outcomes of bone augmentation in the aesthetic zone of the anterior teeth using computer-aided design and a 3D-printed template.

METHODS

Ten patients with severe bone defects in the aesthetic zone of anterior teeth were included in the study; CT data were collected before surgery. The design of the osteotomy line in the bone defect area was determined under computer simulation. The position parameters and osteotomy line of the free bone were determined via virtual surgery. A 3D-printed template was prepared to guide the accurate placement of the bone graft. Reexamination was conducted to evaluate the position of the bone graft immediately after the operation and the resorbed capacity of the bone graft before implant restoration.

RESULTS

The position of the bone graft was consistent with the preoperative design. The amount of bone graft resorbed was within the acceptable range three months after the operation, and the effect of implant restoration was satisfactory.

CLINICAL SIGNIFICANCE

Use of computer-aided design and a 3D-printed template can be an effective approach for accurate bone augmentation in the aesthetic zone of the anterior teeth.

Removal of broken screws on implant abutment by digital guide plate: A case report and literature review

Implant restoration is currently the most mainstream method for repairing missing teeth. With the increasing number of plantings, various planting complications begin to be paid attention to. Among them, there are many reports of disability phenomena such as loose and broken abutment screws and broken top screws, which cause the implant to fail or fail to function. In recent years, with the development of computer-aided software and its application in the field of oral treatment, digital guide plates based on 3D printing of oral CBCT scanning data are widely used in oral implants. Therefore, we explore the application prospect of post-core crown restoration after removing broken screws from the implant abutment with a digital guide plate. We reported a case of upper right first molar implant abutment screws broken, which were removed by a digital guide plate and customized turning bur. The resin-matrix ceramics crown post core was prepared, and then the occlusal force was tested by the T-ScanIII system. It provides a reference for the application of digital guide plates in special cases such as broken screws of implant abutment.

Transmucosal abutments in the esthetic zone: Surgical and prosthetic considerations

OBJECTIVE

This article describes an updated step-by-step protocol for transmucosal abutment selection and treatment sequencing after immediate implant placement in the esthetic zone.

CLINICAL CONSIDERATIONS

Current surgical and prosthetic concepts strive to preserve hard and soft-tissues to provide optimal esthetics at the implant-abutment interface. Consequently, restoring implants in the esthetic zone with transmucosal abutments presents a great challenge and must take into consideration implant depth, angulation, and bucco-lingual position as well as transmucosal height and space for an optimized emergence profile of the restoration and the dimensions of the anterior tooth to be restored. The proper selection of the type, shape, and dimensions of implant components and connections, determined by the product portfolio offered by the implant manufacturer, play a critical role in the ability to adequately address these challenges. This article provides an update on surgical and prosthetic workflows for single implant restorations in the esthetic zone.

CONCLUSIONS

Following esthetic, mechanical, and biologic principles, the long-term success of implant-supported restorations in the esthetic zone is directly correlated to proper execution and sequencing of surgical and prosthetic treatment steps, especially after immediate implant placement. These steps must be critically assessed based on the current scientific evidence to achieve the desired clinical outcomes on a predictable and consistent basis.

CLINICAL SIGNIFICANCE

Selection of surgical and prosthetic treatment protocols to achieve ideal esthetic outcomes and emergence profiles in implant dentistry is often a great challenge, not only determined by technical and clinical skills of the provider but also by the type and dimensions of implant components and connections offered by the manufacturer. Following certain decision-making principles and workflows are key for clinical success with implant-supported restorations after immediate implant placement the esthetic zone.

Copy-paste concept: Full digital approach in the management of gingival emergence profiles

OBJECTIVE

Obtaining a perfect integration of a prosthetic rehabilitation on natural teeth and implantys in the esthetic zone requires a deep knowledge of the biological processes and a clear understanding of the characteristics of the restorative materials. Once the soft tissue profile has been created with the placement of a temporary prosthesis, the ability to accurately transfer information about the tissue profile and the contour of the restoration for the fabrication of the definitive crowns can be challenging.

CLINICAL SIGNIFICANCE

This paper illustrate the copy paste full digital workflow, a simple protocol that allows to create definitive restorations by making an exact copy of the temporary prosthesis that has been placed in function in the patient's mouth.

Digital workflow for low-cost 3D-printed custom healing abutment based on emergence profile CBCT segmentation

Several protocols have been used with computer-aided design and computer-aided manufacture (CAD-CAM) prostheses after image-guided implant surgery based on a prosthetically driven surgical plan. For delayed approaches, a CAD-CAM custom healing abutment can be manufactured before the surgery and installed immediately after implant placement. However, information on the use of emergence profile segmentation on which to base the digital design and on the use of low-cost 3-dimensional printers to produce custom healing abutments are lacking. The purpose of this article was to present a fully digital workflow to digitally design and 3-dimensionally print custom healing abutments with a biocompatible light-polymerizing resin based on the natural emergence profile of the tooth to be replaced.

Digital workflow for designing an interim implant-supported restoration with an optimal emergence profile in an open-source software program

The esthetics and emergence profile design of implant-supported restorations in the anterior zone can be challenging. This dental technique describes a digital approach to designing an optimal emergence profile from the implant head to the definitive prosthetic volume with facial cutback for an esthetic implant-supported interim crown. A printed interim implant-supported restoration with an adequate emergence profile and a facial cutback for composite resin layering is obtained.

Anterior implant restorations with a convex emergence profile increase the frequency of recession: 12-month results of a randomized controlled clinical trial

AIM

To test whether the emergence profile (CONVEX or CONCAVE) of implant-supported crowns influences the mucosal margin stability up to 12 months after insertion of the final restoration.

MATERIALS AND METHODS

Forty-seven patients with a single implant in the anterior region were randomly allocated to one of three groups: (1) CONVEX (n = 15), implant provisional and an implant-supported crown both with a convex profile; (2) CONCAVE (n = 16), implant provisional and an implant-supported crown both with a concave profile; (3) CONTROL (n = 16), no provisional (healing abutment only) and an implant-supported crown. All patients were recalled at baseline, 6, and 12 months. The stability of mucosal margin along with clinical, aesthetic, and profilometric outcomes as well as time and costs were evaluated. To predict the presence of recession, multivariable logistic regressions were performed and linear models using generalized estimation equations were conducted for the different outcomes.

RESULTS

Forty-four patients were available at 12 months post-loading. The frequency of mucosal recession amounted to 64.3% in group CONVEX, 14.3% in group CONCAVE, and 31.4% in group CONTROL. Regression models revealed that a CONVEX profile was significantly associated with the presence of recessions (odds ratio: 12.6, 95% confidence interval: 1.82-88.48, p = .01) compared with the CONCAVE profile. Pink aesthetic scores amounted to 5.9 in group CONVEX, 6.2 in group CONCAVE, and 5.4 in group CONTROL, with no significant differences between the groups (p = .735). Groups CONVEX and CONCAVE increased the appointments and costs compared with the CONTROL group.

CONCLUSIONS

The use of implant-supported provisionals with a CONCAVE emergence profile results in a greater stability of the mucosal margin compared with a CONVEX profile up to 12 months of loading. This is accompanied, however, by increased time and costs compared with the absence of a provisional and may not necessarily enhance the aesthetic outcomes.

TRIAL REGISTRATION

German Clinical Trials Register; DRKS00009420.

Association between Peri-Implant Soft Tissue Health and Different Prosthetic Emergence Angles in Esthetic Areas: Digital Evaluation after 3 Years’ Function

Background: The aim of the present retrospective study was to assess peri-implant soft tissue health for implants restored with different prosthetic emergence profile angles. Methods: Patients were treated with implants supporting fixed dentures and were followed for 3 years. Buccal emergence angle (EA) measured at 3 years of follow-up visits (t1) were calculated for two different groups: Group 1 (153 implants) for restorations with angle between implant axis and prosthetic emergence angle from ≥30°, and Group 2 (67 implants) for those with angle ≤30°, respectively. Image J software was used for the measurements. Moreover, peri-implant soft tissue parameters such as pocket probing depth (PPD), plaque index (PI) and gingival index (GI) were assessed, respectively. Results: A total of 57 patients were included in the analysis and a total of 220 implants were examined. Mean (±SD) EA in Groups 1 and 2 was 46.4 ± 12.2 and 24.5 ± 4.7 degrees, respectively. After 3 years of follow-up, a PPD difference of 0.062 mm (CI_95% −0.041 mm; 0.164 mm) was calculated between the two groups and was not statistically significant (p = 0.238). Similar results were found for PI (OR = 0.78, CI_95% 0.31; 1.98, p = 0.599). Furthermore, GI scores of 2 and 3 were found for nine implants (5.9%) in Group 1, and for five implants in Group 2 (7.5%). A non-significant difference (p = 0.76) was found. Conclusions: Peri-implant soft-tissue health does not seem to be influenced by EA itself, when a proper emergence profile is provided for implant-supported reconstructions in anterior areas.

A digital workflow for pair matching of maxillary anterior teeth using a 3D segmentation technique for esthetic implant restorations

We investigated a state-of-the-art algorithm for 3D reconstruction with a pair-matching technique, which enabled the fabrication of individualized implant restorations in the esthetic zone. This method compared 3D mirror images of crowns and emergence profiles between symmetric tooth pairs in the anterior maxilla using digital slicewise DICOM segmentation and the superimposition of STL data. With the outline extraction of each segment provided by 100 patients, the Hausdorff distance (HD) between two point sets was calculated to identify the similarity of the sets. By using HD thresholds as a pair matching criterion, the true positive rates of crowns were 100, 98, and 98%, while the false negative rates were 0, 2, and 2% for central incisors, lateral incisors, and canines, respectively, indicating high pair matching accuracy (> 99%) and sensitivity (> 98%). The true positive rates of emergence profiles were 99, 100, and 98%, while the false negative rates were 1, 0, and 2% for central incisors, lateral incisors, and canines, respectively, indicating high pair matching accuracy (> 99%) and sensitivity (> 98%). Therefore, digitally flipped contours of crown and emergence profiles can be successfully transferred for implant reconstruction in the maxillary anterior region to optimize esthetics and function.

Digital Workflow for Immediate Implant Placement and Chairside Provisionalization in the Esthetic Zone

Introduction

Immediate implant placement and immediate chairside provisionalization in the esthetic zone require meticulous treatment planning. A digital workflow that combines intraoral scans and a cone beam computed tomography scan can be used to visualize the surgical and restorative aspects of the treatment and to plan a prosthetically driven implant position. A digital workflow in implant dentistry enables the prefabrication of an individualized CAD/CAM temporary restoration, based on the planned implant position. This could be a predictable method to deliver a screw-retained temporary restoration, directly after static computer-assisted immediate implant surgery. Interventions. Three patients with a failing tooth in the maxillary esthetic zone were treated with immediate implant placement and chairside provisionalization using this digital workflow. After 3 months, a final restoration was placed. Clinical, radiographic, and patient-reported outcome measures were collected prior to implant treatment, 6 weeks after placing the temporary restoration and then 1 month and 1 year after placing the final restoration. Outcomes. At the 1-year follow-up, healthy soft tissues were observed, and peri-implant bone levels were stable. Patient satisfaction after the treatment was high.

Conclusion

The three reported cases demonstrate the potential for predictable immediate implant placement and chairside provisionalization using a digital workflow.

The flat and step (F and S) pontics. Novel pontic designs for periodontally reconstructed sites

OBJECTIVE

Fixed dental prostheses are a predictable treatment option to replace missing teeth. A periodontal-prosthodontic approach to rehabilitating those areas ensures a predictable way to achieve the desired esthetic and functional results. This is especially important in cases with high esthetic demand. An ideal esthetic result can be achieved by soft tissue overcorrection through periodontal procedures, which reduce the number of conditioning appointments of the pontic sites. Many pontic designs have been described to enhance the appearance of the restored sites. The flat (F) and step (S) pontic designs are a modification of classic pontic approaches. These designs contact the mucosa in a wide area of a previously reconstructed ridge without exerting excessive pressure, reducing the possibility of inflammation, ulceration, and facilitating cleaning. This periodontal-prosthodontic procedure aims to achieve functional and esthetic prosthodontic results in a predictable manner.

CLINICAL CONSIDERATIONS

Understanding which pontic design is recommended in different clinical situations is key for a successful outcome. The F and S pontic designs are recommended to be used in a ridge with optimal soft tissue volume after periodontal reconstruction. The suggested designs provide the clinician with a solution to different clinical scenarios after the periodontal augmentation of the pontic site has been done.

CONCLUSIONS

The presented pontic designs are indicated in ridges where a previous soft tissue preservation or reconstruction procedure has been done to achieve an optimal soft tissue volume. Modifications to the designs can be done in the interim stage which is later replicated into the final restoration.

CLINICAL SIGNIFICANCE

The combination of periodontal and prosthodontic techniques help to predictably achieve a natural looking pontic emergence profile.

Dimensional Changes in the Alveolus after a Combination of Immediate Postextraction Implant and Connective Grafting and/or Socket Shield Technique

Immediate implant placement protocols after dental extraction have enabled a reduction in surgical phases. This procedure has increased patient satisfaction and similar survival rates to late implant placement procedures. However, placing an implant immediately after dental extraction does not counteract the physiological remodeling of alveolar bone. For this reason, additional surgical techniques have been developed, such as the placement of a connective tissue graft (CTG) or the socket shield technique (SST). Dimensional changes in the peri-implant tissues were observed after placement of immediate implants following the extraction and CTG and/or SST. A total of 26 surgical interventions were carried out in which dimensional change variables of peri-implant tissues were analyzed. The preoperative state and immediate postoperative situation were compared with the situation after one year. Measurements were taken at 3, 5, and 7 mm from the gingival margin and analyzed in this CBCT radiological study (Planmeca Promax 3D). The implant platform was used as a reference point for the measurement of changes in alveolar crest height. One year after performing either of the two techniques (CTG and/or SST), a significant increase in the gingiva thickness and vestibular cortex occurred at 5 mm (0.65 ± 1.16 mm) and 7 mm (0.95 ± 1.45 mm) from the gingival margin. Additionally, an increase in thickness of palatal bone was registered at 3 mm (0.48 ± 0.90 mm). The graft placement group showed an increase in thickness of peri-implant tissue in the vestibular area after one year, although CTG and SST groups were clinically similar. The implementation of SST revealed promising results regarding the buccal thickness of hard and soft tissues after one year. A significant increase in vestibular cortical bone thickness, as well as the overall mucosa thickness and buccal bone at 3 mm from the gingival margin, was observed. A significant reduction in the distance from the bone crest to the platform was detected in both techniques. Both techniques (CTG and SST) are appropriate to provide sufficient volume to peri-implant tissues in the vestibular area of anterior maxillary implants. Some limitations were detected, such as the lack of an aesthetic analysis or small sample size, so results should be interpreted with caution. Future studies are necessary to further evaluate the long-term predictability of these techniques.

Titanium Base Abutments in Implant Prosthodontics: A Literature Review

Implant abutments are essential components in restoring dental implants. Titanium base abutments were introduced to overcome issues related to existing abutments, such as the unesthetic appearance of titanium abutments and the low fracture strength of ceramic abutments. This study aimed to comprehensively review studies addressing the mechanical and clinical behaviors of titanium base abutments. A search was performed on PubMed/MEDLINE, Web of Science, Google Scholar, and Scopus databases to find articles that were published in English until December 2020 and that addressed the review purpose. A total of 33 articles fulfilled the inclusion criteria and were included for data extraction and review. In vitro studies showed that titanium base abutments had high fracture strength, adequate retention values, particularly with resin cement, and good marginal and internal fit. Although the clinical assessment of titanium base abutments was limited, they showed comparable performance with conventional abutments in short-term evaluation, especially in the anterior and premolar areas. Titanium base abutments can be considered a feasible treatment option for restoring dental implants, but long-term clinical studies are required for a better assessment.

An interdisciplinary approach to orthodontic treatment of a mutilated Class III malocclusion with mini-implants, dental implants, and an autotransplant

This case report demonstrates the interdisciplinary treatment of a 24-year-old female. Her skeletal discrepancy, anterior crossbite, mutilated dentition, and midline deviation made it challenging to achieve satisfactory treatment results, especially without major orthognathic surgery. This article thoroughly discusses the decision-making process associated with various treatment alternatives, the biomechanical considerations with temporary skeletal anchorage devices, and the detailed operational process of dental implant restoration and autotransplantation. CLINICAL SIGNIFICANCE: Orthodontic treatment aims to obtain better facial and dental esthetics, achieve functional occlusion, and improve oral health. Treatment of patients with a mutilated dentition requires interdisciplinary teamwork from a group of professionals with various types of expertise. Orthodontists should be the navigator that generates the tooth movement and space redistribution, thus facilitating the subsequent functional rehabilitation under a well-organized occlusal architecture. Autotransplantation offers an economical and biologically-friendly opportunity to replace a missing tooth.

Evaluation of Immediate Implantation and Provisionalization Combined with Guided Bone Regeneration by a Flap Approach in the Maxillary Esthetic Zone: A Retrospective Controlled Study

The aim of this research was too compare the thickness change of labial contour and bone tissues, as well as some biological complications of immediate implantation with and without immediate provisionalization for a single anterior maxilla presenting a vertical defect on labial bone with the need of guided bone regeneration (GBR) by a flap approach. A total of 40 single implants were placed in 40 patients into fresh extraction sockets of the anterior maxilla with a vertical defect on the labial bone (<4 mm). Simultaneously, GBR was conducted at the sites by a flap approach, and the implants were given immediate or delayed provisionalization. The thickness change of bone tissues during six-month evaluation and labial contour during three and six-month follow-up were measured. Complications such as implant and restoration survival rates, infection as well as wound exposure were also evaluated at six months postoperatively. After six months, the mean thickness losses in labial bone were 0.9040, 0.8050, 0.7165, 0.5285 and 0.5335 mm at five different sites in immediate provisionalization group, and 0.8780, 0.8605, 0.7560, 0.5900 and 0.6300 mm, respectively, in delayed provisionalization group, showing no significant difference between the groups at all measurement sites. Although the labial contour changes of the two groups were similar at most sites, the values at 1 and 2 mm above the implant neck remained significantly lower in the immediate provisionalization group at three and six months postoperatively. No complications occurred during the follow-up time. Based on the limitation of this study, the immediate implantation combined with GBR, flap operation and immediate provisionalization obtained acceptable outcomes for a single anterior maxilla with vertical defect on the labial bone, but more long-term research with a larger sample are urgently needed in the future.

Selected Spectroscopic Techniques for Surface Analysis of Dental Materials: A Narrative Review

The presented work focuses on the application of spectroscopic methods, such as Infrared Spectroscopy (IR), Fourier Transform Infrared Spectroscopy (FT-IR), Raman spectroscopy, Ultraviolet and Visible Spectroscopy (UV-Vis), X-ray spectroscopy, and Mass Spectrometry (MS), which are widely employed in the investigation of the surface properties of dental materials. Examples of the research of materials used as tooth fillings, surface preparation in dental prosthetics, cavity preparation methods and fractographic studies of dental implants are also presented. The cited studies show that the above techniques can be valuable tools as they are expanding the research capabilities of materials used in dentistry.