Esthetic considerations related to bone and soft tissue maintenance and development around dental implants: report of the Committee on Research in Fixed Prosthodontics of the American Academy of Fixed Prosthodontics

Palatal Pedicle Connective Tissue for Reconstruction of Through-and-Through Soft Tissue Defects in Esthetic Zone Around a Dental Implant: An 8-Year Follow-Up Case Report

Soft tissue management for immediate implant placement in the esthetic zone is crucial for successful treatment outcomes. Several surgical and restorative techniques have been proposed to treat unesthetic implant soft tissue defects or dehiscence. However, there is a scarcity of clinical evidence on addressing complications associated with through-and-through soft tissue defect (TTSD). In this case, a 61-year-old female patient, who underwent immediate implant placement at the right central incisor 3 months prior, presented with chronic peri-implant mucosal infection and soft tissue recession of TTSD in 2015. The palatal pedicle connective tissue flap (PPCTF) was utilized to provide horizontal and vertical soft tissue augmentation and to cover the defect in combination with the labial contour collapse. At the 8-year follow-up, favorable white and pink esthetic outcomes were observed, and the pink esthetic score (PES) for soft tissue around the implant achieved 9 points, indicating satisfactory esthetic and functional results. The findings from this case study suggest that soft tissue augmentation techniques, such as PPCTF grafts, can provide a reliable and innovative method for both soft tissue augmentation and reconstruction of TTSD, resulting in long-lasting functional and esthetic outcomes and stable ideal PES scores.

Aesthetic problems related to dental implants in the aesthetic zone: A systematic review

Background

Patient satisfaction is a crucial indicator of a successful dental implant treatment. Attainment of an aesthetically acceptable final result is central to this success. Hence, the primary objective of this systematic review was to identify aesthetic concerns linked to dental implants within the aesthetic zone.

Methods

An electronic search was conducted on different databases such as PubMed, Medline, and Google Scholar using the key terms "tooth implant," "anterior implant," "dental implantation in the aesthetic zone," and "aesthetic area implant. Following the elimination of duplicate articles and adherence to the inclusion criteria, 14 articles (five randomized clinical trials, four prospective clinical trials, four case series, and one pilot study) published between 2007 and 2020 were deemed suitable for this review.

Results

The selected studies highlighted several aesthetic issues, such as recession, marginal bone loss, gingival loss, and pink aesthetic scores related to dental implants placed in the aesthetic zone.

Conclusion

Addressing these challenges necessitates meticulous treatment planning, effective soft tissue management, regular follow-ups, patient education, expectation management, and collaborative efforts among specialists. A limitation of this systematic review is that it focused solely on studies conducted within a relatively short timeframe (2007-2020). However, it is essential to recognize that significant changes occurred in the treatment procedures and materials within the field during this period. These changes have resulted in notable variances in the treatment protocols utilized across studies, potentially affecting the generalizability of the findings.

Histological evaluation of osseointegration between conventional and novel bone-level tapered implants in healed bone-A preclinical study

AIMS

To histologically compare osseointegration and crestal bone healing between newly introduced tapered, self-cutting bone-level test implants and tapered bone-level control implants in sites with fully healed sites.

METHODS

Sixty-six implants (33 test, 33 control) were placed 1 mm subcrestally in a minipig model and underwent qualitative histologic and quantitative histometric analyses after 3, 6 and 12 weeks of submerged healing. The primary and secondary outcomes were the bone-to-implant contact (BIC) and first bone-to-implant contact (fBIC). Outcomes between the test and control implants were statistically compared.

RESULTS

The BIC values of the test implants were comparable and non-inferior over the time points studied, except for the 12 weeks time point which showed statistically significantly higher BIC values of the test (88.07 ± 5.35%) compared to the control implants (80.88 ± 7.51%) (p = .010). Similarly comparable and non-inferior were the fBIC values, except for the 6-week outcome, which showed statistically higher values for the test (-546.5 ± 450.80 μm) compared to the control implants (-75.7 ± 100.59 μm). fBIC results for the test implants were qualitatively more stable and consistent between test time points.

CONCLUSION

Novel self-cutting bone-level test implants demonstrated superior osseointegration and similar bone levels compared to conventional bone-level implants after a healing period of 12 weeks in healed ridges.

Clinical outcomes of narrow- and regular-diameter implants with bone augmentation in the anterior maxilla: a systematic review and meta-analysis

OBJECTIVES

To evaluate the clinical outcomes of narrow-diameter implants (NDIs) and regular-diameter implants (RDIs) with bone augmentation in the anterior maxilla, with implant survival rate (ISR) as the primary outcome. Additionally, secondary outcomes such as peri-implant marginal bone loss (MBL), pocket probing depth (PPD), mechanical complications, and biological complications were also considered.

MATERIALS AND METHODS

A thorough literature search was performed to identify randomized controlled trials and cohort studies comparing outcomes of NDIs and RDIs with bone augmentation in the anterior maxilla published up to February 2024. Only studies with a minimum follow-up period of 12 months were selected for analysis. Meta-analysis was performed if at least two articles with similar characteristics were available.

RESULTS

Of the 288 articles initially considered, 5 were included in the analysis, involving 282 NDIs and 100 RDIs. At the 36-month follow-up, no statistically significant differences in ISR, which ranged 93.8-100% for NDIs and were 100% for RDIs, were observed between the two groups (relative risk, 0.989; 95% confidence interval, 0.839-1.165; p = 0.896). Similarly, MBL and PPD did not differ significantly between the two groups. Soft tissue dehiscence was the most common complication found in RDIs.

CONCLUSION

The results indicate that NDIs yield clinical outcomes similar to those of RDIs with bone augmentation in the anterior maxilla over a 36-month follow-up period.

CLINICAL RELEVANCE

Considering the similar clinical outcomes, the shortened treatment duration and more rapid esthetic improvement associated with NDIs may render them preferrable to RDIs with bone augmentation, particularly in this esthetic zone.

Enhancing the gingival contour of an anterior implant restoration by using a guided bone regeneration abutment

Deficiencies in the alveolar bone and surrounding gingiva can pose challenges in implant placement within the esthetic zone. This clinical report describes the reconstruction of gingival tissue contours through guided bone regeneration (GBR) in the anterior maxilla during implant placement by using a modified titanium abutment to maintain the osteogenic space adjacent to the gingival margin and implant neck.

Peri-Implant Marginal Bone Changes around Dental Implants with Platform-Switched and Platform-Matched Abutments: A Retrospective 5-Year Radiographic Evaluation

Preserving the marginal bone level (MBL) is essential for the long-term success of dental implant therapy, and bone remodeling around dental implants is considered to vary with time. Numerous studies comparing the platform-switching (PS) and platform-matching (PM) dental implants have indicated that PS dental implants showed a lesser reduction for the MBL, and the majority of them had a relatively short period. This study aimed to evaluate vertical and horizontal bone defects by using digital periapical radiographs to examine the changes in MBL around PM and PS dental implants over 5 years after functional loading. The vertical MBL (vMBL) was measured from the implant-abutment junction to the first bone-to-implant contact. The horizontal MBL (hMBL) was measured from the implant-abutment junction to the bone crest. All data were presented as means ± standard errors. Paired and independent t-tests with Welch's correction were used to analyze the data. A total of 61 dental implants in 38 patients after 5 years of functional loading were evaluated. Over time, PS dental implants were more likely to gain bone; by contrast, PM dental implants were more likely to lose bone during the observation time. Changes in vMBL for PS dental implants were significantly less than those for PM dental implants at 1-year (p = 0.045), 3-year (p = 0.021), and 5-year (p = 0.010) loading. Likewise, changes in hMBL for PS dental implants were significantly smaller than in those for PM dental implants at 3-year (p = 0.021) and 5-year (p = 0.006) loading; however, the changes were minimal in both approaches. PS dental implants had a significant increment in the percentage of bone integration, whereas that for PM dental implants dropped over time, with no significance. In PS dental implants that occlude with natural teeth, vertical and horizontal bone gain was observed, and it was significant at 3 years (p = 0.023). A significant horizontal bone gain was observed in the opposing natural teeth at 3-year (p = 0.002) and 5-year loading (p = 0.002). The PS concept appears to preserve more MBL around dental implants by stabilizing the vMBL and hMBL over a 5-year period. A minimal marginal bone change was detected in both concepts. The opposing natural teeth at PS dental implants showed a favorable effect on marginal bone tissues.

[Use of dental implants in orthopedic rehabilitation of patients in aesthetically important area]

The article presents a review of scientific data of Russian and non-Russian works dedicated to the problem of instant dental implantation in the aesthetically important areas, i.e. the upper jaw. The paper considers such anatomical factors of unsatisfactory aesthetic treatment results as presence and thickness of vestibular alveola wall, pathophysiological processes occurring while extracting teeth in this area, presence of odontogenic inflammatory sites and traumatic injuries under root canal and orthopaedic treatment, impact of gum's biotype on the condition of soft tissue in the area of the future orthopaedic prothesis. Data used in the article suggests the necessity of thorough diagnostic with the help of up-to-date technologies such as Cone beam computer tomography (CBCT).

Peri-implant bone preservation of a novel, self-cutting, and fully tapered implant in the healed crestal ridge of minipigs: submerged vs. transgingival healing

OBJECTIVES

The aim of this study was to assess the influence of transgingival compared with submerged healing on peri-implant bone maintenance around a novel, fully tapered implant in a healed crestal ridge in minipigs.

MATERIALS AND METHODS

In each of 12 minipigs, two implants (Straumann® BLX, Roxolid® SLActive®, Ø 3.75 × 8 mm) were placed. Implants were either left for submerged or for transgingival healing for 12 weeks. Measurements performed were bone-to-implant contact (BIC), first bone-to-implant contact (fBIC), bone area to total area (BATA), perpendicular bone crest to implant shoulder (pCIS), bone height change from placement, and bone overgrowth (for submerged implants).

RESULTS

No significant differences were found between transgingival and submerged healing in any of the measured parameters, except for BATA on the buccal aspect in which significantly more bone formation was found for the transgingival healing group. For both groups, there was a gain in crestal bone height during the 12-week healing period.

CONCLUSIONS

Loaded compared with unloaded implants displayed comparable levels of osseointegration and equivalent marginal bone levels. This qualifies the implant placement protocol with respect to the osteotomy dimensions and subcrestal placement protocol for immediate loading.

CLINICAL RELEVANCE

The here presented results related to osseointegration and crestal bone maintenance after submerged or transgingival healing have demonstrated a high level of consistency in the used in vivo translational model. The obtained results support the translation of the novel implant type in conjunction with the developed surgical workflow and placement protocol into further clinical investigation and use.

Influence of implant location on titanium-zirconium alloy narrow-diameter implants: A 1-year prospective study in smoking and nonsmoking populations

STATEMENT OF PROBLEM

Titanium-zirconium (Ti-Zr) alloy (Roxolid) narrow-diameter implants (NDIs) have been widely used for implant-supported prostheses in anterior and posterior regions in the jaws. However, the relationship between implant location and clinical outcome remains unclear.

PURPOSE

The purpose of this clinical study was to evaluate and compare the clinical and radiographic outcomes of NDIs placed in different regions of the jaws in both smokers and nonsmokers.

MATERIAL AND METHODS

Eighty-four participants scheduled to receive NDIs for tooth rehabilitation were included, and the inserted NDIs were divided into 3 groups depending on their locations: implants used to restore anterior teeth, implants used to restore premolars, and implants used to restore molars. Crestal bone loss (CBL), implant survival and success rates, bleeding on probing (BOP), and pocket probing depth (PPD) were evaluated 6 and 12 months after implant loading (α=.017 for implant survival and success rates after Bonferroni correction, α=.05 for other parameters).

RESULTS

Statistical analysis of 6- and 12-month CBL of all participants presented no statistically significant difference among the 3 groups. For smokers, the molar group presented significantly more CBL than the premolar group (0.90 ±0.94 versus 0.16 ±0.27 mm, P=.027) at the 6-month examination. The implant survival rates were 95.65%, 100%, and 100% for anterior, premolar, and molar regions, respectively (P=.283). No statistically significant difference was observed regarding periodontal parameters (P>.05).

CONCLUSIONS

Implant location has no influence on the clinical and radiographic parameters of Ti-Zr NDIs placed in a nonsmoking population. However, the combination of posterior location and smoking may induce higher risk of crestal bone loss. Caution should be taken when restoring molars for smokers with NDIs.

Use of alveolar distraction osteogenesis for anterior maxillary defect reconstruction

Alveolar osteogenic distraction (AOD) is a biological process through which new bone formation occurs between bone segments that are gradually separated by incremental traction. This case report described the oral rehabilitation with dental implants of a patient with a vertical bone defect in the maxillary anterior region using the AOD technique. The patient presented with absence of the teeth 22, 21, 11, and 12 associated with a vertical bone defect. The AOD was performed using a supported osteodistractor device surgically installed with subsequent daily activations. After 21 days, the ideal positioning of bone fragment was confirmed and activation was ceased. Five months after the initial surgery, two dental implants were installed in the region of teeth 12 and 22. An FP3 metal–ceramic prosthesis was installed offering satisfactory esthetic results. In conclusion, the use of AOD to increase the alveolar ridge was effective and ensured rehabilitation with dental implants.

Bone Level Measurements Around Platform Switched and Platform Matched Implants: A Comparative Study

BACKGROUND

The overall success of dental implants depends on the crestal bone support around the implants. During the initial years, the bone loss around the implants determines the success rate of treatment. Platform switching (PLS) preserves the crestal bone loss, and this approach must be applied clinically.

AIM

The purpose of this study was to determine the changes in vertical and horizontal marginal bone levels in platform-switched and platform-matched dental implants.

MATERIALS AND METHODS

One fifty patients received one fifty dental implants in the present study over a 1-year period. Measurement was performed between the implant shoulder and the most apical and horizontal marginal defect by periapical radiographs to examine the changes of peri-implant alveolar bone before and 12 months after prosthodontic restoration delivery.

RESULTS

These marginal bone measurements showed a bone gain of 1.56 ± 2.4 mm in the vertical gap and 1.49 ± 2.24 mm in the horizontal gap of the platform matching, while in the PLS, a bone gain of 2.67 ± 2.0 mm in the vertical gap (P < 0.05) and 2.89 ± 1.67 mm in the horizontal gap was found. Only a statistically significant difference was found comparing bone gains in the vertical gap between the two groups (P < 0.05).

CONCLUSION

PLS helps preserve crestal bone around the implants, and this concept should be followed when clinical situations in implant placement permit.

Dental Implant Surrounding Marginal Bone Level Evaluation: Platform Switching versus Platform Matching-One-Year Retrospective Study

The benefits and feasibility of platform switching have been discussed in several studies, reporting lesser crestal bone loss in platform-switched implants than in platform-matched implants. Objective. The aim of the present study was to observe the changes in vertical and horizontal marginal bone levels in platform-switched and platform-matched dental implants. Materials and Methods. 51 patients received 60 dental implants in the present study over a 1-year period. Measurement was performed between the implant shoulder and the most apical and horizontal marginal defect by periapical radiographs to examine the changes of peri-implant alveolar bone before and 12 months after prosthodontic restoration delivery. Results. These marginal bone measurements showed a bone gain of 0.23 ± 0.58 mm in the vertical gap and 0.22 ± 0.53 mm in the horizontal gap of platform matching, while in platform switching a bone gain of 0.93 ± 1 mm (P < 0.05) in the vertical gap and 0.50 ± 0.56 mm in the horizontal gap was found. The average vertical gap reduction from the baseline until 12 months was 0.92 ± 1.11 mm in platform switching and 0.29 ± 0.85 mm in platform matching (P < 0.05). Conclusions. Within the limitations of the present study, platform switching seemed to be more effective for a better peri-implant alveolar bone vertical and horizontal gap reduction at 1 year.

Implant-Abutment Contact Surfaces and Microgap Measurements of Different Implant Connections Under 3-Dimensional X-Ray Microtomography

PURPOSE

The presence of a microgap between implant and abutment could produce a bacterial reservoir which could interfere with the long-term health of the periimplant tissues. The aim of this article was to evaluate, by x-ray 3-dimensional microtomography, implant-abutment contact surfaces and microgaps at the implant-abutment interface in different types of implant-abutment connections.

MATERIALS AND METHODS

A total of 40 implants were used in this in vitro study. Ten implants presented a screw-retained internal hexagon abutment (group I), 10 had a Morse Cone taper internal connection (group II), 10 another type of Morse Cone taper internal connection (group III), and 10 had a screwed trilobed connection (group IV).

RESULTS

In both types of Morse Cone internal connections, there was no detectable separation at the implant-abutment in the area of the conical connection, and there was an absolute congruity without any microgaps between abutment and implant. No line was visible separating the implant and the abutment. On the contrary, in the screwed abutment implants, numerous gaps and voids were present.

CONCLUSIONS

The results of this study support the hypothesis that different types of implant-abutment joints are responsible for the observed differences in bacterial penetration.

Simplified custom impression post for implant-supported restorations

The esthetic outcome of an implant-supported restoration is greatly influenced by the relationship between the contours of the definitive prosthesis and the periimplant tissues. In this clinical technique, an implant analog holder and autopolymerizing acrylic resin were used to accurately register the soft-tissue transition zone created by the interim restoration and transfer it to the impression post during the definitive impression.

Assessment of buccal bone thickness of aesthetic maxillary region: a cone-beam computed tomography study

Purpose

The aim of this study was to analyze the anatomical dimensions of the buccal bone walls of the aesthetic maxillary region for immediate implant placement, based upon cone-beam computed tomography (CBCT) scans in a sample of adult patients.

Methods

Two calibrated examiners analyzed a sample of 50 CBCT scans, performing morphometric analyses of both incisors and canines on the left and right sides. Subsequently, in the sagittal view, a line was traced through the major axis of the selected tooth. Then, a second line (E) was traced from the buccal to the palatal wall at the level of the observed bone ridges. The heights of the buccal and palatal bone ridges were determined at the major axis of the tooth. The buccal bone thickness was measured across five lines. The first was at the level of line E. The second was at the most apical point of the tooth, and the other three lines were equidistant between the apical and the cervical lines, and parallel to them. Statistical analysis was performed with a significance level of P≤0.05 for the bone thickness means and standard deviations per tooth and patient for the five lines at varying depths.

Results

The means of the buccal wall thicknesses in the central incisors, lateral incisors and canines were 1.14±0.65 mm, 0.95±0.67 mm and 1.15±0.68 mm, respectively. Additionally, only on the left side were significant differences in some measurements of buccal bone thickness observed according to age and gender. However, age and gender did not show significant differences in heights between the palatal and buccal plates. In a few cases, the buccal wall had a greater height than the palatal wall.

Conclusions

Less than 10% of sites showed more than a 2-mm thickness of the buccal bone wall, with the exception of the central incisor region, wherein 14.4% of cases were ≥2 mm.

The influence of the connection, length and diameter of an implant on bone biomechanics

BACKGROUND

Regardless of the multiple options of connections, diameters and heights for dental implants, the clinician should know the biomechanical behavior of the bone to plan the treatment according to the biological and anatomical conditions of each patient, without risk to the long-term treatment success.

REVIEW

The following review attempts to summarize the relevant literature to establish guidelines for clinicians based on the scientific evidence regarding the influence by the implant's connection, diameter and length on the bone biomechanics.

CONCLUSIONS

The length, diameter and connection of each implant have a degree of influence in bone biomechanics. Despite the influence of different implant connections, diameters and lengths on peri-implant bone stress and strain, these characteristics should remain within the physiological limits to avoid a pathological overload, bone resorption and consequent risk to the long-term success of implant-prosthetic treatment.

The Digital One-Abutment/One-Time Concept. A Clinical Report

The digital fabrication of dental restorations on implants has become a standard procedure during the last decade. Avoiding changing abutments during prosthetic treatment has been shown to be superior to the traditional protocol. The presented concept for implant-supported single crowns describes a digital approach without a physical model from implant placement to final delivery in two appointments. A 54-year-old man was provided with a single-tooth implant on his left mandibular first molar. Before wound closure, the implant position was captured digitally with an intraoral scanning device. After bone healing at the time of second-stage surgery the final screw-retained crown fabricated without a physical model was inserted. Soft tissue healing took place at the definitive restoration, avoiding abutment changes or changes of the healing cap. These led to stable soft tissues with a minimum of surgery. The benefits of digital fabrication and the unique way to scan the implant right after placement give an additional value that would not be achieved by analog techniques. In addition to financial benefits it represents a biologically advantageous, one-abutment/one-time approach with customized screw-retained, full-contour crowns or cemented crowns on custom abutments.

Esthetic failure in implant dentistry

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

Use of implant-supported interim restorations to transfer periimplant soft tissue profiles to a milled polyurethane definitive cast

A customized impression coping is often used in conjunction with conventional implant impression techniques to transfer a well-defined periimplant soft tissue profile resulting from an implant-supported interim restoration to the definitive cast with a removable gingival replica and achieve the desired esthetic outcome of the definitive restorations. However, a direct line of sight between the intraoral scanner and the periimplant soft tissue is needed during the data acquisition of the digital impression techniques, and it is not possible to use customized scannable impression copings to support periimplant soft tissue. This study describes a clinical technique with implant-supported interim restorations to transfer desired periimplant soft tissue profiles to the milled definitive polyurethane cast with a removable periimplant soft tissue replica to maximize the esthetic outcome of the definitive restorations.