The Root Membrane Technique: Human Histologic Evidence after Five Years of Function.Biomed Res Int. 2017;2017:7269467. [PMID: 29333449 DOI: 10.1155/2017/7269467]

Finite element analysis of stress distribution on residual root structure in socket shield procedure following immediate dental implant placement: an in vitro study

BACKGROUND

The success of implants in the socket shield technique relies on stress experienced by root fragments within the socket. Although there is no consensus on optimal root fragment thickness, varying thicknesses and dynamic implant placement induce stress in various directions and degrees. This study aimed to assess biomechanical response and stress distribution across different root fragment thicknesses in the socket shield procedure.

METHODS

This in vitro study was conducted to assess and compare the stress distribution on residual root structures of varying thicknesses positioned within the labial aspect of the maxillary incisor socket during immediate implant placement of standard dimensions. The procedure involved applying an insertional torque of 40 Ncm, and the analysis was conducted using finite element analysis software.

RESULTS

Utilizing the Numerical Technique with Abaqus software for explicit dynamics, von Mises stress and principal strain were analyzed on the root structure and bone under nonlinear contact conditions during implant torque application. For Model A, a loading torque of 40 Ncm was applied vertically on the implant, along with a horizontal force of 20 N on the root structure and bone. Results indicated maximum stress of 12.68 MPa on the root structure with a thickness of 0.5 mm and 5.61 MPa on the bone, with principal strains of 6.82E-03 and 4.10E-03, respectively. In Model B, with a root structure thickness of 1.0 mm, the maximum stress increased to 19.70 MPa, while the bone stress rose to 9.51 MPa, with principal strains of 1.03E-02 and 6.09E-03. Model C, with a root structure thickness of 1.5 mm, exhibited a maximum stress of 21.58 MPa on the root and 10.12 MPa on the bone, with principal strains of 1.16E-02 and 6.10E-03. Lastly, in Model D, with a root structure thickness of 2.0 mm, the maximum stress on the root structure and bone escalated to 28.74 MPa and 11.38 MPa, respectively, with principal strains of 1.55E-02 and 8.31E-03.

CONCLUSIONS

As the thickness of the shield increases (ranging from 0.5 to 2 mm) in socket shield procedures with immediate implant placement, both stress on the root fragment and bone and principal micro-strain escalate. However, employing a shield thickness within the range of 0.5 to 2 mm does not lead to any adverse stress generation on the residual root fragment. However, for enhanced safety, it is recommended to restrict the maximum diameter and extension of the root fragment to 1.5 mm when considering implant sizes and socket diameter for the socket shield technique.

Socket shield technique: Stress distribution analysis

Background

To analyze through finite element analysis the stress distribution in peri-implant bone tissues, implants, and prosthetic components induced by the socket shield (SS) technique in comparison to other techniques used to treat tooth loss.

Materials and Methods

A three-dimensional model of a superior central incisor crown supported by implant was modeled and three different placement conditions were simulated: SS - 2.0-mm-thick root dentin fragment positioned between the alveolar buccal wall and implant; heterologous bone graft (HBG) - bovine bone graft positioned the alveolar buccal wall and implant; and control (C) - implant fully placed in bone tissue of a healed alveolus. The model was restricted at the lateral surfaces of the bone tissue and the following loads were simulated: Both oblique (45°) loads of 100 N on the lingual surface of the crown (maximal habitual intercuspation) and 25.5 N on the incisal edge of the crown (tooth contact during mandibular protrusion) were simultaneously applied. Tensile stress, shear stress, compression, and displacement were analyzed in the cortical bone, trabecular bone, dentin root fragment, and bone graft; while equivalent von Mises stresses were quantified in the implant and prosthetic components.

Results

Stress values of SS and HBG in the bone tissues were higher than C, while slight differences within models were observed for dentin root fragment, bone graft, implant, and prosthetic components.

Conclusions

The SS technique presented the highest stress concentration in the peri-implant tissues.

Comparing Dual-Zone Immediate Implant Placement and Socket Shield Technique for Ridge Width Changes in the Maxilla: A Prospective Cohort Study

PURPOSE

The aim of this prospective cohort study was to assess the facial-palatal ridge dimensional changes that occurred at 8-10 months following flapless dual-zone (DZ) immediate implant placement and socket-shield (SS) immediate placement in the maxilla.

MATERIALS AND METHODS

A total of 19 patients who received 20 implants were included, with 10 implants (MegaGen AnyRidge) placed for each treatment, DZ and SS. Cast models were made at 8-10 months after implant placement to assess the dimensional ridge changes by measuring the facial-palatal ridge width on implant sites (T) at six designated points starting from the gingival margin (0, 1, 2, 3, 5 and 7) and comparing it with the corresponding measurement on the contralateral tooth site (C).

RESULTS

All 20 implants demonstrated successful osseointegration at 8-10 months follow-up (survival rate 100%). Two out of ten cases of SS group presented with minor manageable complications of external shield exposure. DZ group showed an average of 0.3 mm facial-palatal ridge width reduction, while SS group revealed a mean gain in ridge width of approximately 0.2 mm at 8-10 months follow-up.

CONCLUSION

When comparing between two treatments, there was a significant difference in ridge width change at 8-10 months following implant placement, indicating better preservation of the ridge contour for socket shield technique.

Partial Extraction Therapy with Early Implant Placement in the Esthetic Zone: A Clinical Case Report

Immediate replacement of teeth designated for extraction is an appealing treatment rationale for both the patient and the operator. However, it has been associated with a greater risk of facial recession and compromised soft-tissue esthetics. Partial extraction therapy (PET) or synonymously socket shield technique (SST) or root membrane technique (RMT) has been proposed to conserve the facial alveolar contour and soft-tissue esthetics. In this article, a special case is described where a root membrane was used to prevent the modeling of the facial aspect of the extraction socket. Partial extraction was performed allowing the socket with the facial root membrane in situ to partially heal for 8 weeks before implant placement. Successful integration and restoration were achieved with very minimal hard- and soft-tissue changes, accentuating satisfactory esthetic results as dictated by objective esthetic assessment. PET with early implant placement may be considered a viable treatment option for selected cases.

Is socket shielding an option in esthetic region?

The implant cannot preserve the surrounding bone from resorption when placed in the extraction socket. After teeth extraction, a change in the bony architecture of the anterior region makes oral rehabilitation difficult by an implant. This leads us to explore such a critical issue and the relevant data were collected from Pubmed, Google Scholar, and Cochrane database and reviewed. Socket shielding technique is intentional retention of the buccal segment of root fragment during the implant placement in the extraction socket. Socket shielding is an effective procedure in minimizing the buccal bone resorption along with minimizing the buccal contour changes it is minimally invasive as the bone graft is optional thus reducing the cost of the treatment procedure. The limited studies were available to support the routine clinical use of the socket shielding technique. Socket shielding seems to become the non-invasive technique for the preservation of hard and soft tissue by dental implant especially in the esthetic zone in the future. Therefore studies should be carried out on a large population to obtained more précised results related to the socket shielding technique.

Socket shield technique and delayed implant placement in maxilla: a series of five case reports

Background

Tooth extraction is often followed by remodeling of hard and soft tissues, while socket shield technique has been proposed to prevent or minimize this remodeling. Socket shield accompanied with delayed implant placement is a novel technique that could be used when delayed implantation is selected; however, more scientific based evidence is required to recommend this technique as everyday clinical practice. Thus, the aim of this case series was to assess the clinical, radiographic, and esthetic outcomes of the delayed placed implants associated with previously prepared socket shield at 3–15 months follow-up after loading. The stability of the shield and the depth of soft tissue penetration palatal to the shield at reentry of 3–6 months were also assessed.

Cases presentation

Five case reports of socket shield with delayed implant placement were described in the study. The facial shields were prepared and simultaneously the sockets were grafted with mineralized allograft particles, then the implants were placed 3–6 months later. Periodontal probe was used to measure the depth of soft tissue penetration palatal to the shield at reentry. Clinical indices of bleeding index, plaque index, and probing depths were recorded. Radiographic evaluation to record the amount of marginal bone loss post-loading, esthetic assessment using modified pink esthetic score, and patient assessed outcomes were also evaluated at 3–15 months follow-up after loading. At 3–6 months reentry, all shields were stable with maintenance of the facial bone and with extreme hard tissue formation in the sockets. All five implants were successful and functional without any pain or inflammation, with optimal soft tissue health and esthetics, and with minimal radiographic marginal bone loss at the last follow-up visit (3–15 months after loading).

Conclusions

Within the limits of this study, socket shield technique with delayed implant placement could be a predictable minimally invasive option for cases requiring delayed implant placement; however, a long-term well-designed clinical proof is warranted.

The socket shield technique and its complications, implant survival rate, and clinical outcomes: a systematic review

PURPOSE

The aim of this systematic review was to evaluate the effectiveness of the socket shield technique (SST), an innovative surgical method introduced in 2010, for reducing buccal bone plate resorption.

METHODS

The review was conducted following the PRISMA guidelines. Clinical studies conducted in humans and investigating the SST were searched on PubMed (MEDLINE), Embase, Web of Knowledge, and Google Scholar in November and December 2021. The implant survival rate, percentage of complications, and clinical parameters (marginal bone loss [MBL], pink esthetic score [PES], and buccal bone plate resorption [BBPR]) were analyzed using the collected data.

RESULTS

The initial search resulted in 132 articles. After article screening, the full texts of 19 studies were read and 17 articles were finally included in the review. In total, 656 implants were installed with the SST. Nine of the 656 implants experienced failure, resulting in an implant survival rate of 98.6%. The percentage of complications was about 3.81%. The analysis of clinical parameters (MBL, PES, and BBPR), showed favorable results for the SST. The mean MBL in implants placed with the SST was 0.39±0.28 mm versus 1.00±0.55 mm in those placed without the SST. PES had a better outcome in the SST group, with an average of 12.08±1.18 versus 10.77±0.74. BBPR had more favorable results in implants placed with the SST (0.32±0.10 mm) than in implants placed with the standard technique (1.05±0.18 mm).

CONCLUSIONS

The SST could be considered beneficial for preserving the buccal bone plate. However, since only 7 of the included studies were long-term randomized controlled trials comparing the SST with the standard implant placement technique, the conclusions drawn from this systematic review should be interpreted with caution.

TRIAL REGISTRATION

PROSPERO Identifier: CRD42020180637.

Pink esthetic and radiological scores around immediate implants placed in the esthetic zone - Socket-Shield Technique versus Immediate Conventional Technique: A Pilot Study

Objective:

It is irrefutable that the extraction of teeth inextricably results in definitive changes in the surrounding hard and soft tissues. Recently, Socket-Shield Technique (SST) has been used to keep the buccal two-third of the root intact in the socket. This buccal shield further preserves the periodontium-bundle bone complex and hence preserves the buccal hard and soft tissue. The purpose of the study was to do a statistical comparative analysis of two different types of flapless and graftless techniques using the esthetic (Pink Esthetic Index) and radiological parameters.

Materials and Methods:

A total of thirty nonrestorable tooth/root stumps (vital or nonvital) were selected and randomly allocated to two different groups: control group with immediate conventional implant placement (without SST) (Group C, n = 15) and test group with immediate implant placement using SST (Group S, n = 15). All of the sites received immediate chairside temporaries. All implants were restored either with screw- or cement-retained prostheses 4 months postoperative. Each control and test group was analyzed at two different durations: 15 days after placement of provisional and 15 days after placement of definitive prosthesis. Five parameters of Pink Esthetic Score (PES) were used for esthetic analysis, and digital periapical radiographs were used for radiographic analysis.

Results:

Within the time frame of the study (15 days postplacement of definitive prosthesis), a statistically significant difference (p < 0.05) was observed between PES of the two techniques. Test group S (mean = 9.07) showed better scores than control group C (mean = 6.87). It was observed that buccal bone was maintained in all the cases of test group S while there was loss of buccal bone in almost all the cases of control group C.

Conclusion:

Within the limitations of this short-term pilot study, better soft-tissue parameters were observed with SST as compared to a conventional graftless technique whenever a restoration on immediate implant placement is considered.

Fate of root shell after pontic/socket shield techniques, is it better to extract the whole tooth?

A series of changes occur in the remaining alveolar process after whole tooth extraction. The basic question is, why do the bony walls (especially the labial/buccal) get resorbed immediately after the tooth is removed? This could be because, with cementum of the concerned tooth and its periodontal ligament, the supporting bundle bone is dependent on the presence of the tooth. This loss can be compensated using numerous techniques, such as socket grafting using various biomaterials to preserve the alveolar bone and buccal grafting with guided tissue regeneration to increase the thickness of buccal bone or placement of implant immediately. However, none of these techniques prevent the modelling of the alveolar bone post-extraction. Few studies have demonstrated that preservation of the roots in the alveolar process maintains the bone volume and facilitates vertical bone growth. A histological study in animals and humans has shown that the retained root shell does not pose any interference in the osseointegration of the implant (if placed simultaneously). Although various names have been proposed to describe the concept of retaining full or part of the root to prevent the resorption of the ridge, socket-shield and pontic-shield are the two most commonly used terms worldwide. The extraction of the whole tooth might be the choice of therapy when socket-shield or pontic-shield is not possible due to anatomical variations, infections, or lack of clinical expertise. Irrespective of the size, when a whole root or a root fragment (is left in situ), it is the dentist’s ethical duty to advise/inform the patient and ensure repeated clinical and radiographic follow-up. The present study aimed to highlight the current status of these techniques, their benefits, and possible complications and address whether the paradigm of the teeth extraction methods should be altered.

The socket shield technique for immediate implant placement: A systematic review and meta-analysis

BACKGROUND

Immediate implant placement with socket shield technique (SST) may maintain the buccal bone plate and soft tissue levels, however, the potential clinical benefits of SST lack strong scientific evidence. The aim of this systematic review and meta-analysis was to evaluate the effects of SST on dimensional changes of hard tissues, esthetic outcomes, implant stability, complication, and implant failure rates.

METHODS

Electronic databases were searched to identify randomized controlled trials (RCTs) that compared immediate implant placement with and without SST. The risk of bias was assessed using the Cochrane Collaboration's Risk of Bias tool. Data were analyzed using a statistical software program.

RESULTS

A total of 982 studies were identified, of which, seven RCTs with 206 immediately placed dental implants in 191 participants were included. Overall meta-analysis showed significant differences in the changes in buccal bone plate width (mean difference (MD) -0.22; 95% confidence interval (CI) -0.30 to -0.15; p < 0.0001) and height (MD -0.52; 95% CI -0.85 to -0.18; p = 0.002) in favor of SST. The use of SST was also associated with significantly less changes in peri-implant marginal bone levels and better pink esthetic score than immediately placing implants without SST. The differences in implant stability, complication and implant failure rates were not statistically significant between immediate implant placement with or without SST.

CONCLUSIONS

The short-term complication and implant failure rates following immediate implant placement with or without SST were comparable. The SST has short-term positive effects on the changes in width and height of buccal bone plate, peri-implant marginal bone levels and esthetic outcomes. Further evidence from long-term RCTs are still required to substantiate the current findings.

CLINICAL SIGNIFICANCE

SST can reduce changes in buccal plate width and height and improve the soft tissue profile following immediate implant placement in esthetic zone.

Failure Rate, Marginal Bone Loss, and Pink Esthetic with Socket-Shield Technique for Immediate Dental Implant Placement in the Esthetic Zone. A Systematic Review and Meta-Analysis

Aim: To compare the failure rate, marginal bone loss, and pink esthetic for the socket-shield technique and the conventional technique for immediate dental implant placement in the esthetic zone. Material and methods: A systematic literature review and meta-analysis, based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations, of clinical studies that evaluated the failure rate, marginal bone loss, and pink esthetic with the socket-shield technique for immediate dental implant placement in the esthetic zone was performed. A total of 4 databases were consulted in the literature search: PubMed-MEDLINE, Scopus, Embase, and Web of Science. After eliminating duplicated articles and applying the inclusion criteria, 16 articles were selected for the qualitative and quantitative analysis. Results: Four randomized controlled trials, five prospective clinical studies, four retrospective studies, and three case series were included in the meta-analysis. The dental implant failure rate for the socket-shield technique for immediate dental implant placement was 1.37% (95% CI, 0.21-2.54%); however, no statistically significant differences between the conventional and socket-shield technique were found. The estimated mean difference in the marginal bone loss for the socket-shield technique was -0.5 mm (95% CI, -0.82 to -0.18) and statistically significant (p < 0.01), with a high heterogeneity (I² = 99%). The mean pink esthetic score was 12.27 (Q test = 4.47; p-value = 0.61; I² = 0%). The difference in pink esthetic between the conventional (n = 55) and socket-shield techniques (n = 55) for immediate dental implant placement was 1.15 (95% CI, 0.73-1.58; Q test = 8.88; p value = 0.11; I² = 44%). The follow-up time was found to be significant (beta coefficient = 0.023; R² = 85.6%; QM = 3.82; p = 0.049) for the PES for the socket-shield technique. Conclusions: Within the limitations of this systematic review with meta-analysis, the dental implant failure rate did not differ between the socket-shield technique and conventional technique for immediate implant placement in the esthetic zone. However, a lower marginal bone loss and higher pink esthetic scores were found for the socket-shield technique compared to the conventional technique.

Comparison of the soft and hard peri-implant tissue dimensional changes around single immediate implants in the esthetic zone with socket shield technique versus using xenograft: A randomized controlled clinical trial

OBJECTIVE

Compare the dimensional changes of the peri-implant soft and hard tissues clinically and radiographically around single immediate implants in the esthetic zone with socket shield technique versus filling the buccal gap with xenograft.

MATERIALS AND METHODS

Forty-two patients with a single non-restorable tooth in the esthetic zone replaced with an immediate implant were randomly assigned either to the socket shield technique (test) or to grafting the buccal gap with xenograft (control). The vertical and horizontal buccal bone resorption were measured 6-months following implant placement. The esthetic outcomes were evaluated by assessing the Pink Esthetic Score (PES) and the amount of midfacial mucosal alteration, in addition to patient satisfaction assessment through a Visual Analogue Scale (VAS) based questionnaire 1-year following implant restoration.

RESULTS

The present study showed that the socket shield group yielded significantly less vertical and horizontal buccal bone resorption of 0.35 (±0.62) mm and 0.29 (±0.34) mm compared to 1.71 (±1.02) mm and 1.45 (±0.72) mm in the xenograft group respectively. Also, there was a significantly greater midfacial mucosal recession in the xenograft group of 0.466 (±0.58) mm compared to midfacial mucosal coronal migration of 0.45 (±0.75) mm in the socket shield group. However, there was no statistically significant difference regarding the total PES and patient satisfaction in both treatment groups.

CONCLUSION

The socket shield technique can preserve hard and soft peri-implant tissues following immediate implant placement. (ClinicalTrials.gov Identifier: NCT03684356).

The socket-shield technique: a critical literature review

Introduction

Dental implants have become a standard treatment in the replacement of missing teeth. After tooth extraction and implant placement, resorption of buccal bundle bone can pose a significant complication with often very negative cosmetic impacts. Studies have shown that if the dental root remains in the alveolar process, bundle bone resorption is very minimal. However, to date, the deliberate retention of roots to preserve bone has not been routinely used in dental implantology.

Material and methods

This study aims to collect and evaluate the present knowledge with regard to the socket-shield technique as described by Hurzeler et al. (J Clin Periodontol 37(9):855-62, 2010). A PubMed database search (www.ncbi.nlm.nih.gov/pubmed) was conducted to identify relevant publication.

Results

The initial database search returned 229 results. After screening the abstracts, 13 articles were downloaded and further scrutinised. Twelve studies were found to meet the inclusion and exclusion criteria.

Conclusion

Whilst the socket-shield technique potentially offers promising outcomes, reducing the need for invasive bone grafts around implants in the aesthetic zone, clinical data to support this is very limited. The limited data available is compromised by a lack of well-designed prospective randomised controlled studies. The existing case reports are of very limited scientific value. Retrospective studies exist in limited numbers but are of inconsistent design. At this stage, it is unclear whether the socket-shield technique will provide a stable long-time outcome.

The (in)adequacy of translational research in dentistry

Translational research, as the name suggests, "translates" research findings into clinical practice to improve the health of human beings. The translational process builds on information from experiments conducted at a basic level (i.e., in vitro and/or animal studies) and progresses over experimental human studies for efficacy, efficiency, and safety to implementation. Therefore, all steps in the process should be based on studies conducted with the highest methodological quality possible in order to provide accurate and useful information. Furthermore, the systematic dissemination of new procedures/techniques should be done only when they have been proven to be effective and safe. This focus article describes examples of new techniques/procedures in dentistry that have not resulted from an adequate translational research process since the initial evidence was published. These procedures are generally characterised by lack of good evidence, particularly on their potential harms, and lack of adequate chronological order, regarding the translational research process (i.e., human research being conducted before animal research). Even so, they seem to be widely disseminated, and their promotion involves a wide range of sources, including social media. Some guidance is proposed to improve the quality of the translational research process in dentistry, as well as the level of awareness of all parties involved with the use of this research: clinicians, researchers, and patients. By improving the translational research process, optimization of the application and use of these resources, with less risk to the patients, is expected.

Socket-shield technique for implant placement to stabilize the facial gingival and osseous architecture: A systematic review

The aim of the present study was to establish the efficacy of the socket-shield technique (SST) for the stabilization of the facial gingival and osseous architecture. An electronic search including the Cochrane databases, EBSCOhost, Medline/PubMed and Web of Science was performed. Articles related to SST for placing dental implants were included. Articles and abstracts not written in English were excluded. The initial literature search resulted in 113 articles related to questions raised. Hand searching of the journals related to implants and cross-referencing related to SST within the selected articles resulted in 1 more paper. Finally, 20 full texts and abstract of 1 article were included in the present systematic review: 11 case reports, 6 case series, 1 human randomized control trial (RCT), 1 technical report and 2 animal RCT. Recent modifications in SST, along with long follow-up studies with increased sample size, provided promising results. This systematic review still recommends that SST should not be used in routine clinical practise until a higher level of evidence established. Further RCT on SST are required to establish the clinical efficacy of this technique.

The Root Membrane Technique: A Retrospective Clinical Study With Up to 10 Years of Follow-Up

PURPOSE

Immediate implant placement in conjunction with intentional root retention is a recently introduced technique, but the majority of existing documentation is limited to short-term reports with low level of evidence. Hence, the aim of this study was to document the long-term clinical and radiographic results of the root membrane technique.

METHODS

This retrospective study reports on clinical results of the root membrane technique for periodontal ligament-mediated immediate implant placement with up to 10 years of follow-up from 3 private dental practices. Anterior implants placed with immediate loading from January 2006 to December 2016 were assessed. Kaplan-Meier estimators were computed for reporting of implant success and survival.

RESULTS

A sample of 182 patients (82 men and 100 women, age range: 18-83 years) received 250 immediate implants (230 maxilla, 20 mandible) after the root membrane concept and followed-up for a mean of 49.94 months (±32.5). Overall, 5 implant failures were recorded for a 10-year cumulative patient-level implant survival rate of 96.5%. Considering mechanical and biological complications, the 10-year cumulative implant success rate was 87.9%.

CONCLUSIONS

Within the limits of the retrospective design, the root membrane technique showed long-term success rates comparable to those of conventional immediate implants.

The Modified Socket Shield Technique

OBJECTIVE

In the anterior regions, the resorption of the buccal bone after tooth extraction leads to a contraction of the overlying soft tissues, resulting in an esthetic problem, particularly with immediate implant placement. In the socket shield technique, the buccal root section of the tooth is maintained, to preserve the buccal bone for immediate implant placement. The aim of this prospective study was to investigate the survival, stability, and complication rates of implants placed using a "modified" socket shield technique.

METHODS

Over a 2-year period, all patients referred to a dental clinic for treatment with oral implants were considered for inclusion in this study. Inclusion criteria were healthy adult patients who presented nonrestorable single teeth with intact buccal periodontal tissues in the anterior regions of both jaws. Exclusion criteria were teeth with present/past periodontal disease, vertical root fractures on the buccal aspect, horizontal fractures below bone level, and external/internal resorptions. The buccal portion of the root was retained to prevent the resorption of the buccal bone; the shield was 1.5 mm thick with the most coronal portion at the bone crest level. All patients then underwent immediate implants. In the patient with a gap between the implant and shield, no graft material was placed. All implants were immediately restored with single crowns and followed for 1 year. The main outcomes were implant survival, stability, and complications.

RESULTS

Thirty patients (15 males, 15 females; mean age was 48.2 ± 15.0 years) were enrolled in the study and installed with 40 immediate implants. After 1 year, all implants were functioning, for a survival rate of 100%; excellent implant stability was reported (mean implant stability quotient at placement: 72.9 ± 5.9; after 1 year: 74.6 ± 2.7). No biologic complications were reported, and the incidence of prosthetic complications was low (2.5%).

CONCLUSIONS

The "modified" socket shield technique seems to be a successful procedure when combined with immediate implant placement, because the root fragment does not interfere with osseointegration and may be beneficial for the esthetics, protecting the buccal bone from resorption.

The effect of the heights and thicknesses of the remaining root segments on buccal bone resorption in the socket-shield technique: An experimental study in dogs

BACKGROUND

To date only a few studies have been done on the use of the socket-shield technique for preserving the resorption of the buccal bone in aesthetically sensitive sites. Besides, there have been no further studies on the effect of the heights and thicknesses of the remaining root segments on buccal bone resorption when using this method.

PURPOSE

The aim of this study was to evaluate the effect of different heights and thicknesses of the remaining root segments on bone resorption in the socket-shield technique.

MATERIALS AND METHODS

Four healthy female beagle dogs were used in this study. The third premolar (P3) and the fourth premolar (P4) on both sides of the mandible were hemisected in the buccal-lingual direction, and the clinical crown of the distal root was beheaded. In the experimental groups, the roots were worn down in the apical direction until they were located at the buccal crestal level (Group A) or 1 mm higher than that level (Group B). In the control group, the distal root segments were extracted. Then, implant placement was performed into the distal root. After 3 months of healing, the specimens were prepared for histological diagnosis.

RESULTS

There was no difference between Group A and Group B when using the socket-shield technique, but the results of both groups were better than those of the control group.

CONCLUSIONS

The height of the root segments has little effect on the bone absorption of alveolar bone, while the bone absorption was strongly influenced by the thickness of the root segments. More precisely, the absorption may decrease if the thickness of the root fragment increases, when the thickness of the root plate is in the 0.5-1.5 mm range.

Shield the socket: Procedure, case report and classification

The extraction of a tooth leads to a cascade of events which results in resorption of the alveolar bone around the socket. The buccal bone loss that occurs postextraction leads to vertical and horizontal bone loss. It requires complex hard and soft-tissue reconstruction to achieve esthetically pleasing results in such cases. In the socket-shield technique (SST) the root is bisected, and the buccal two-third of the root is preserved in the socket so that the periodontium along with the bundle bone and the buccal bone remains intact. A classification of SST technique is proposed depending on the position of the shield in the socket. This classification is required so as to help in understanding the preparation design and the role of shield and in maximizing the usage of the shield to achieve best possible esthetics in immediate implant placement sites.