Abstract
Background. Rehabilitation in the anterior region requires specific conditions for success, such as the presence of papilla, emergence profile, and balance between pink and white esthetic.
Objectives. This systematic review aimed to evaluate the esthetic risk associated with immediate implant placement with immediate restoration in the anterior superior area, where the facial bone plate may be absent or deficient.
Materials and methods. The search was done in PubMed, Embase, Cochrane, Lilacs, Scopus, Scielo, and Google Scholar databases. The investigation involved clinical studies and observational studies published between January 2012 and July 2023. Studies were excluded if there was less than 12-month follow-up, no immediate restoration or facial defect, heavy smokers, or systemic disease. The risk of bias was assessed using the ROBINS-I and Modified-Cochrane RoB tools.
Results. Twelve studies were included in this systematic review. The thinner the facial plate, the higher the alveolus’s risk of gingival recession or shrinkage. There was an increased interproximal recession when the thin phenotype was associated with flap surgery. An increase in pink esthetic score (PES) was reached when immediate implant placement (IIP) and immediate restoration were done. Soft tissue augmentation achieved more gingival-level stability. Regardless of the initial phenotype, an esthetic outcome was delivered. The risk of bias was high in 1 study and moderate in 3 studies.
Conclusions. It is possible to conclude that esthetic results and increased final PES or patient satisfaction index in IIP treatments associated with immediate restoration could be obtained even in buccal bone wall defects or gingival recession, regardless of their extension.
Key words: esthetic region, facial bone plate deficiency, immediate implant placement, immediate restoration, peri-implant recession
Background
Several clinical situations can predispose patients to tooth loss,1, 2, 3 which can cause functional impairment and esthetic challenges for clinicians. Rehabilitation in the anterior zone requires specific conditions for success, such as the presence of papilla, an emergence profile, and a balance between pink and white esthetics.4 Previous studies5, 6, 7, 8 suggest that buccal-plate bone loss results in esthetic sequelae, mainly influenced by the reduction/absence of papillae and the position of the gingival and/or peri-implant mucosa. Currently, several procedures are proposed to increase the predictability of results.9, 10, 11
Among the available therapies, implant placement following correct three-dimensional (3D) positioning, filling the socket with a bone substitute, using connective tissue graft, and immediate restoration are procedures that can minimize peri-implant tissue loss over time.4, 12, 13, 14, 15 Otherwise, in light of current knowledge, the clinician’s concern in achieving successful rehabilitation is no longer only the success of the osseointegration,16, 17, 18, 19, 20 but also peri-implant esthetics.4, 21
Some factors may interfere with the peri-implant tissue framework in anterior rehabilitation, such as periodontal phenotype, 3D implant position, and prosthetic management with an adequate emergence profile. Then, immediate restoration can be considered an essential variable in the treatment plan,4, 22, 23, 24 especially in areas with a compromised buccal bone plate and high esthetic demand. Therefore, the anterior area of the maxilla present several anatomic and esthetic characteristics that must be considered during dental implant treatment: 1. Thin facial bone that is more prone to resorption due to decreased vascular supply25 after tooth loss26, 27; 2. Reduced buccolingual dimensions and facial bone concavity28, 29, 30; 3. The type of implant connection used due to the risk of bone loss31; 4. Risk of fenestration and exposure of the apical implant’s threads28, 32; and 5. Peri-implant mucosal recession.31, 33, 34
Evaluation of the buccal bone plate demonstrated that most cases were <1 mm thick, with 50% presenting <0.5 mm thickness.35 Moreover, <10% of sites showed buccal plate thickness ≥2 mm.36 Another study reported that the mean width of the facial alveolar bone wall in anterior teeth was around 0.9 mm.37 It is clear that thinner buccal bone will probably result in a greater and considerable amount of vertical bone loss.31 The literature showed that initial buccal bone thickness and subsequent vertical height bone loss (after implantation) were 1.2 mm with a loss of 0.7 mm,33 1.25 mm with a loss of 0.49 mm38 and 0.5 mm with a loss of 1 mm.34 Consequently, the thinner the bone, the greater the vertical loss.
Objectives
Despite the clinical relevance of the topic, well-delineated clinical studies are scarce regarding immediate implant placement (IIP) in anterior sites with buccal bone defects already present. Also, there is a gap in the literature on whether such a condition incurs esthetic problems after the healing period of the peri-implant tissue. As such, the goal of this systematic review was to evaluate the esthetic risk caused by IIP with immediate restoration in the anterior area, where the facial bone plate may be absent or deficient.
This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and was registered on the International Prospective Register of Systematic Reviews (PROSPERO) platform (CRD42022341534). The focus question was developed based on the Patient (P), Intervention (I), Comparison (C), and Outcomes (O) (PICOS) strategy, in addition to the design of the studies (S) conducted.39 The focus question was: “For IIP immediately restored, does the absence of a buccal bone plate mean an increased risk for the esthetic and peri-implant mucosa recession?” P. Patients undergoing at least 1 immediate implant in an esthetic region; I. IIP and immediate restoration in sockets with buccal bone defects; C. Buccal bone defects at the IIP with immediate restoration; O. Recession of the peri-implant mucosa and esthetic risk, and if there are procedures in the literature permitting higher predictability in circumventing this bone defect, allowing a better esthetic result; S. Clinical studies and observational studies (cohort studies, case-control studies and cross-sectional studies).
Eligibility criteria
The criteria for inclusion included: 1. Clinical studies and observational studies (cohort studies, case-control studies and cross-sectional studies); 2. Minimum follow-up of 12 months; 3. IIP with immediate restoration in the anterior superior esthetic region; 4. Evaluation of esthetic clinical parameters; 5. Treated sockets (or study group) with buccal wall defects. The exclusion criteria were: 1. Follow-up time of less than 12 months; 2. Without immediate restoration; 3. Diabetic patients; 4. Smokers consuming more than 10 cigarettes per day; 5. Patients systemically compromised.
Information sources and search strategy
Two independent examiners (PHMPT and RGD) performed a broad search for articles in 7 databases: PubMed/Medline, Embase, Cochrane, Lilacs, Scopus, Scielo, and Google Scholar. The investigation included clinical and observational studies (cohort, case-control and cross-sectional studies) published between January 2012 and July 2023 in any language. It used the following descriptors and combination strategies: “peri-implant soft tissue” OR “gingival recession” OR “gingival deficiency” OR “buccal plate deficiency” OR “facial bone defect” OR “facial bone deficiency” OR “buccal bone defect” AND “immediate implant” OR “single implant” OR “maxillae anterior implant” OR “immediate” OR “immediately” OR “extraction” OR “socket” OR “dental implantation” OR “endosseous implant” OR “dental implants” OR “single tooth” AND “esthetic area” OR “esthetic zone” OR “esthetic region” OR “aesthetic.”
Data collection and selection process and data items
A thorough analysis of the data was performed by 2 independent researchers (PHMPT and RGD) for sequential comparison in Microsoft Excel v. 16.50 (Microsoft Corp., Redmond, USA). Information about the authors, year of publication, type of study, follow-up, number of patients, number of implants, eligibility criteria applied, pre-operative patient evaluation, buccal plate defect size, bone graft used, soft tissue graft, number of teeth extracted, extraction technique, implants’ settings, implant position, postoperative care, provisional restoration and definitive prosthesis delivered, implant success/survival rate, esthetic outcome parameters measured in the study, and conclusions were registered when available.
Risk of bias assessment
The risk of bias was assessed using the Risk of Bias In Non-Randomized Studies – of Interventions (ROBINS-I), which is a tool for the prospective and retrospective case-control papers, and using the Modified Cochrane Risk of Bias tool for the randomized controlled trials (RCTs) included in this research.40 When up to 1 “Y” (Yes) or 1 “high risk” were found, the judgment was “low risk of bias”; if 2 “Y” (Yes) or 1 “high risk” and 1 “unclear” were found, the judgment was “moderate risk”; if 3 “yes” or 2 “high risk,” the judgment was “high risk of bias.”
Results
Screening and study selection
An initial search found 32,904 articles, of which, after filtering for the date (last 11 years and 6 months) and study design – randomized clinical trials, 2,485 works were selected (k = 0.93). After reading the titles, the reviewers excluded 2,081 studies and another 429 due to duplicity. A total of 186 articles were separated for reading of the abstracts, of which 161 were excluded. Of the 25 remaining articles, 13 did not meet the selection criteria because they did not deal with alveoli with vestibular wall defects (Table 1; k = 0.98). Finally, 12 studies were selected for this systematic review (Figure 1).
Study characteristics
Table 2 describes the types of studies analyzed, the mean follow-up time, and the number of implants and patients evaluated. Among the evaluated studies, there were 3 RCTs,41, 42, 43 7 prospective studies44, 45, 46, 47, 48, 49, 50 and 2 retrospective studies.13, 51 The follow-up was from 12 months41, 42, 43, 44, 45, 47, 50 to 7 years,51 and the number of patients included in the studies varied from 100 to 1,245.45, 50 All studies included patients with at least 1 hopeless tooth in the esthetic maxillary area with an indication of extraction and the possibility of IIP, with the maintenance of the adjacent teeth. The eligibility criteria implemented by the studies are summarized in Supplementary Table 1. The preoperative evaluation, size of the vestibular defect, and the presence of bone graft and/or soft tissue are detailed in Table 3.
The extraction technique and postoperative control are summarized in Table 4. The implants were loaded with immediate restoration, lacking occlusal contacts, and the minimum torque reported ranged from 15 N•cm48 to 35 N•cm.43, 44, 49 The presence of an initial esthetic defect had at least 1 mm51 of gingival recession until the total absence of a facial plate.44 Although most of the studies used a minimally invasive technique to remove the target tooth,13, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51 Lee et al.41 compared 2 groups in which 1 used a flapless procedure and the other used a raised flap. The conclusion of each article is summarized in Supplementary Table 2.
Patients’ assessment
For the initial assessment of the patient, a cone beam computed tomography (CBCT) was used, as well as the clinical parameters including the pink esthetic score (PES).50 Photographs, periodontal phenotype, preoperative soft tissue level, and CBCT scans were also used as initial references,42, 48, 49, 51 which permitted comparison with the final restoration. Ferrantino et al.43 treated alveoli with up to 1 mm of bony defect, whereas most authors limited the maximal crestal bone defect to 5 mm.41, 42, 45, 50 Other studies considered different parameters, including 10 mm of vertical bone defect44 and dehiscence of more than 2/3 of the buccal plate.51 Although most treatments involved reconstruction of the buccal plate with different types of graft, some authors did not reconstruct the wall.41, 44 Instead, they intended to compare the local bone and soft tissue changes without the interference of socket grafting after IIP and immediate restoration in the presence of a partial or completely missing buccal bone.
The PES was used to compare initial and final photographs of the patient using the contralateral tooth as a reference.13, 42, 44, 46, 47, 48, 50, 51 Some points were evaluated, such as the medial and distal papillae, soft tissue contour, gingival margin level, soft tissue color, and texture. On the other hand, Ferrantino et al.43 applied the Implant Crown Aesthetic Index (ICAI) to clinical digital photographs taken during the follow-up. In contrast, da Rosa et al.49 chose the gingiva morphometry method. Staas et al.45 and Lee et al.41 assessed the relationship between the bone margin and thickness as well as the interproximal bone peek to measure the esthetic risk of IIP and immediate restoration and gingival/bone changes during the healing time. Some authors also evaluated patient satisfaction.51
Bone graft and soft tissue
In paper by Sicilia-Felechosa et al.,50 the authors did not describe the bone substitute used, while most of the others chose xenografts.43, 45, 47, 51 Two studies had grafted the buccal alveolar space in front of the implant surface with autologous bone chips,13, 48 while 1 decided to use a specific graft technique using thin lamina of bone from tuberosities.49 The association between xenograft and autologous chips was also considered to fill the buccal gap.42, 46, 51
Regarding soft tissue grafts, there was no preference regarding their use or not. While some authors proceeded with gingival volume augmentation,42, 43, 46, 47, 48, 51 others did not consider this option.13, 41, 44, 45, 49, 50 Subepithelial connective tissue grafts removed from the palate42, 46, 47, 48 or tuberosity42 were used to increase gingival volume. Allogenic dermis (AlloDerm RTM, Biohorizons, Allergan Corp., Dublin, Ireland)51 and a collagen matrix (Mucograft, Geistlich, Wolhusen, Switzerland)47 were also considered.
Implant settings
Tapered implants were used in several studies (Table 4).13, 41, 42, 43, 44, 45, 46, 47, 48, 49, 51 Nevertheless, 1 author used a parallel implant,51 and another did not describe the type of implant used.50 The diameter of the implants varied from 3.0 mm45 to 5.1 mm,51 and was chosen based on the socket dimensions. The position of the implant was more palatal, following the best 3D position, creating a gap between the implant surface and the buccal bone wall, which could be filled with graft or not, as described above. This gap ranged from 1 mm41 to 3 mm long44 and was filled as mentioned above. The abutment connection dictates the distance from the perspective of the clinical crown margin to the implant seat. The most commonly described distance was 3–4 mm,42, 45, 46, 47 although implant seats coinciding with the facial bone crest level were found.41
Implant success/survival rate
The implant success rate (Table 4) was measured based on the absence of pain complaints, discomfort, infection, no implant mobility, and no bone loss (less than 1 mm in the 1st year). A high success rate was found in all of the selected papers. Some authors showed a 100% success rate,13, 44, 46, 47, 48, 49 while others described 1 implant loss out of 39%,41 or 96.80% implant survival.43 Others had a success rate of 98.3%,51 96.7%,42 while some had a success rate of around 100% after excluding patients who lost the implant due to trauma or did not undergo the follow-up maintenance.45, 50
Immediate/provisional restoration
The immediate restoration procedure was mandatory to be included in this review (Table 5). Although different restorative protocols were found, all authors used temporary restorative crowns during implant healing. Elaskary et al.46 chose to maintain the gingival architecture with personalized provisional healing at the gingival margin level instead of installing a complete restorative crown. Some authors43, 47, 49 described a subgingival concave contour of the immediate restoration to maintain the gingival margin position and create space for the soft tissue ingrown. Nevertheless, Groenendijk et al.50 differed in 3 clinical situations that could be found during the extraction procedures and 3 restorative approaches: 1. Gingival recession, which should lead to a more concave contour in the subgingival area of the prosthesis, allowing the growth of soft tissue; 2. Gingival margin in the right position, in which the restoration should support the tissue without compression; and 3. When there was a more coronal position of the gingival margin, the restorative crown should compress the soft tissue to promote a controlled recession.
One point of convergence between all authors was the necessity of leaving the immediate restoration with a lack of occlusal contacts. Meanwhile, a healing time of 313, 42, 44, 45, 46, 48 or 6 months41, 43, 47, 49 was allowed before delivering the final restoration (Table 5). Various materials were used for the final crown and the cemented or screw-retained prosthesis. The definitive restorative crowns were made from multiple materials, including metal-ceramic,43, 49 monolithic zirconia, zirconium oxide45, 48 or ceramic.44 Those prosthetic crowns could be 1 piece screwed to the implant43, 45 or 2 pieces using a zirconia abutment to receive the cemented crown.13, 45, 48
Phenotypes and esthetics
Regardless of the importance of the initial phenotype, the thinner the buccal plate thickness, the higher the risk of gingival recession or shrinkage of the alveoli. The final result showed (in most cases across all studies) that the esthetic result can be delivered. The thin phenotype could promote great changes in the mid-buccal gingival margin and the mid-buccal ridge dimension. Also, when combined with flap release, there was an increase in the interproximal gingival recession41 (Table 6).
Even when IIP and immediate restoration involved compromised sockets presenting with buccal bone deficiency or gingival recession, an increase in the PES could be achieved.50 Many different approaches could overcome bone deficiency, as shown by da Rosa et al.,49 and achieved stable peri-implant soft tissue levels after 58 months, even in compromised fresh sockets. Another study24 did not proceed with any kind of buccal plate reconstruction or soft tissue augmentation, and, at the end of the follow-up, still demonstrated an increase in PES for patients treated with IIP and immediate restoration in the presence of bone deficiency, even though minimal adjustment of the restoration had to be performed in every patient due to slight alterations of the gingival margin.
Although the association between buccal gap filling and soft tissue augmentation is not mandatory for satisfactory esthetic results,43 its application adjunctive to immediate restoration in IIP seemed to deliver the most predictable treatment, guaranteeing marginal gingival level stability.42, 46, 47 In addition, using subepithelial connective tissue grafts improved the results compared to other soft tissue substitutes.47 Even though an expected increase in PES was noticed, reaching the maximal score in 73–89% of cases, there was still a risk of a gingival recession of 1–2 mm in around 20% of the treatments.51
Quality assessment
Quality assessment was performed using 2 different risk assessment tools according to the study design. Three RCTs included in this review were assessed using the modified Cochrane risk-of-bias tool,40 while all other papers were judged according to the ROBIN-I risk of bias tool. One paper was classified as high risk of bias, 3 had a moderate risk and 8 had a low risk of bias (Figure 2).
Discussion
This study intended to guide clinicians and clarify the understanding of IIP procedures in esthetic areas, which can involve soft and/or bone tissue grafts to maintain and stabilize the position of the gingival margin. Then, this systematic study aimed to assess whether there is increased esthetic risk in oral rehabilitation with a partial or total absence of the buccal bone plate in esthetic areas when associated with IIP and immediate restoration.
Alveolar bone wall and IIP
Tooth loss leads to alveolar ridge changes in the apical-coronal and buccolingual directions, affecting and compromising the esthetic result of implant-supported rehabilitation. The presence of the marginal bone crest determines the final position of the gingival margin, and the extension of this bone defect can be an esthetic risk factor in IIP. Depending on the bone involvement level, such as in cases of large defects or those involving interproximal areas, alveolar preservation and delayed implant placement have been recommended.52 These types of defects can be classified as: 1. Involving the buccal bone wall, with greater or lesser extension restricted to the medial surface; 2. “V” or “U”-shaped defects; and 3. Defects affecting adjacent teeth, such as “UU” defects. In larger defects or those involving papillae, there is a recommendation to perform alveolar preservation and subsequent placement due to the accentuated risk of marginal recession and compromised final esthetic. However, all studies included in this review presented buccal-wall defects at the time of IIP, with various extensions, with analysis of this paradigm being the goal. Defects ranging from approx. 0.1 mm up to the absence of bone on the entire buccal surface were found, though there was no involvement of the interproximal bone crest.
Elevation of the vestibular flap and exposure of the bone defect can lead to greater procedure-related morbidity, more significant postoperative discomfort, decreased facial blood supply, and compromise the vitality of adjacent tissues.41 Otherwise, flapless surgeries allow greater preservation of the buccal bone. Within these facts, most studies reported13, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 44, 51, 53 this approach for tooth removal, whereas Lee et al.41 used a minimally traumatic approach and flap elevation, randomizing the cases. The authors found a greater interproximal gingival recession in the group where the elevation flap was applied.
The need for an intact buccal wall with an unaltered gingival margin and a considerable buccal bone plate volume for IIP, as described by Buser et al.,54 or the contraindication of IIP due to large and deep bone defects, as recommended by Kan et al.,52 were refuted by Sicilia-Felechosa et al.51 The latter approached IIP with immediate restoration in defects with more than 2/3 of the buccal bone wall compromised or a probing depth of more than 10 mm. Similarly, Pohl et al.44 rehabilitated alveolar sockets with vertical defects ranging from 2.26 mm to 9.68 mm and horizontal defects between 3.2 mm and 5.91 mm, and showed that IIP without additional augmentation, but with immediate provisionalization, was a viable alternative even with the buccal wall missing in the esthetic maxillary zone.
Buccal space and bone grafts
The literature suggests that spaces of at least 2 mm between the implant surface and the buccal wall region, either from the remnant buccal-bone plate or from the buccal mucosa in patients with buccal-wall defects, must be filled by bone grafts to promote a thicker buccal bone wall when >2 mm-wide buccal gaps followed by IIP is done.55 In addition, it can favor an adequate emergence profile of less than 30°.45 The ideal, or more palatal, implant position could be achieved in a guided manner46, 51 or by using the palatal wall as a reference. The correct 3D position of the implant consisted of an apical-coronal position 3–4 mm below the ideal gingival margin27, 42, 44, 45, 46, 47 in the rehabilitations using conical connections. Meanwhile, in the rehabilitations using internal parallel connections, the implants were positioned at the bone crest level.41
The correct choice of grafting material to fill the gap allows the maintenance of ridge volume to minimize the losses arising from the facial wall remodeling.45 The filling of this space was conducted in some studies43, 45, 47, 51 using xenograft, while autogenous bone was the material of choice in other studies.42, 46, 51 Other authors13, 47, 48 chose only autogenous bone differing in particulates or bone lamina removed from the tuberosity; the final esthetic result was not negatively affected even though some decrease of marginal bone level occurred. The research with tuberosity bone did not evaluate the bone response through time, only the soft tissue aspect.
Immediate restoration and esthetic score
Recent studies reported results without augmentation to fill the gap or using a connective tissue graft. They compared intact and defective alveoli walls in which IIP and immediate restorations were performed with a flap or flapless procedure; moreover, they verified the influence of the subgingival contour in the tissue response.41, 44 There was an association between flap release and increased interproximal gingival recession,41 and, despite reporting that the esthetic result could be achieved in all cases regardless of the group, adjustments in the prosthetic margins of less than 0.2 mm had to be performed to make the definitive implant-supported restoration.44
In general, preparation of the immediate restoration must respect the contours of the gingival architecture to promote soft tissue support without causing pressure on the gingival margin. In contrast, this contour must be concave below this margin in a subcritical space, allowing soft tissue growth. However, Groenendijk et al.50 observed that in the presence of a more coronal position of the gingiva, the provisional restoration should compress the gingival margin and promote apical migration of the soft tissues. The temporary restoration must have no occlusal contact during the wound healing period. Noelken et al.13 considered splinting it with the adjacent teeth to prevent micromovements. The permanence of the provisional restoration can range from 3 to 6 months.
Although the recommendation for connective tissue grafts combined with IIP is found in the literature,4 increasing the predictability of results, some authors showed no difference in esthetics evaluation and patient satisfaction when comparing those with soft tissue grafts to a group without tissue augmentation.42, 43 Ferrantino et al.43 described that the complexity of the treatment might explain the different conclusions; the final result of the treatment can also be influenced by the correct development of the provisional restoration, which would help not only in assuring esthetic satisfaction of the patient but also in better healing of the post-extraction socket and the stability of the peri-implant soft tissue. Moreover, the more palatal positioning of the implant, the more influence it has on the maintenance of the gingival margin, allowing space for the creation of a thicker bone crest (after filling the gap) and soft tissue volume gain, even without the need for grafting,44 leading to similar results when treating patients with or without gingival margin defects.50
Elaskary et al.46 demonstrated that the obtention of a buccal bone plate approx. 2 mm thick was possible, even with large bone defects at the time of tooth extration; however, this was not associated with soft tissue defects. In that study, compensation for the lack of facial wall was provided by a mix of autogenous and xenograft biomaterials covered by a collagen membrane and subepithelial connective tissue graft. Also, both groups (without buccal-wall defects and partially lacking them) had a good score for the peri-implant soft tissue level. Pohl et al.44 did not perform any soft or hard tissue graft augmentation to compare alveoli that had IIP with or without defects; therefore, they verified improvement or maintenance of the PES in most cases. In addition, in all cases, regardless of the group, adjustments in the prosthetic margins were made to obtain the definitive prostheses.
The technique chosen by Sicilia-Felochosa et al.51 was autogenous or allogeneic connective tissue grafts combined with bone filling of the facial defect (autogenous bone grafts and/or deproteinized bovine bone mineral) without a collagen membrane. The authors obtained a 98% success rate over a 7-year follow-up. High success rates were associated with good esthetic results, with more than 70% of patients having a PES equal to or greater than 12 (PES index between 0 and 14). However, 8 out of 39 patients followed up (21.6%) had a 1–2 mm recession, compromising the final score.
Frizzera et al.47 compared the results of 3 groups that received IIP, analyzing the different responses for connective tissue graft, collagen matrix and non-soft tissue augmentation. In all procedures, the gaps were filled with bone grafts covered by collagen membranes to isolate the buccal defect. The best result was found when utilizing an autogenous connective tissue graft, maintaining the volume obtained after 12 months. In addition, even though no recession was detected in the groups, the palatal position of the implant associated with a subcritical prosthetic contour allowed tissue growth. Therefore, soft tissue depression or color change was observed when the autogenous soft tissue was not used.
Limitations
The present systematic review had some limitations: 1. A low number of clinical studies were included (n = 12), which suggests that more well-standardized trials with long-term analysis are required to better verify tissue stability; 2. No other biomaterial was used to fill the gap between the implant and buccal wall or combined with the implant,17 such as bone graft with platelet-rich fibrin (PRF) or PRF alone. This fact can be considered in future investigations due to the potential of healing presented by PRF56, 57; 3. 33.3% of the studies (n = 4) had a moderate or high risk of bias; 4. Only 1 study showed long-term results (around 58 months); 5. Hexagon implants were sometimes used, which typically cause more marginal bone loss than morse-taper implants58; and 6. There was some divergence in the type of tools used among the studies, which can cause impairment or confusion; 7. The effect of abutment disconnection, which is important for the maintenance of soft tissue height, was not evaluated in the included studies.
Conclusions
Considering the limitations of this systematic review, the consensus was that an esthetic result and increased final PES or patient satisfaction index in IIP treatments associated with immediate restoration could be obtained even in the presence of buccal bone wall defects or gingival recession, regardless of their extension. Thus, there is no absolute contraindication for this type of treatment, but extreme attention to the treatment plan is recommended.
Supplementary data
The Supplementary materials are available at https://doi.org/10.5281/zenodo.8410418. The package includes the following files:
Supplementary Table 1. Inclusion and exclusion criteria used in the studies selected in this study.
Supplementary Table 2. Conclusions of the evaluated studies.