Histopathologic observations on late oral implant failures

Stabilized oral lichen planus does not compromise dental implants survival: A systematic review and meta-analysis

BACKGROUND

This study aimed to evaluate the incidence of implant failure in patients with oral lichen planus (OLP) and investigate the potential association between OLP and peri-implant diseases.

MATERIALS AND METHODS

Embase, Web of Science, PubMed, and Scopus databases were searched for studies with no time restrictions. Meta-analysis was performed calculating pooled proportion of peri-implantitis (PI), peri-implant mucositis (PIM), and bleeding on probing (BOP) prevalence using fixed-effects model. Odds ratio and corresponding 95% CI were calculated to assess the potential risk of PI, PIM, and BOP in dental implant patients with OLP compared to healthy controls.

RESULTS

Implant failure rate was 4.38% at the patient level and 4.37% at the implant level. Six patients (3.92%) from five studies were diagnosed with oral cancer after receiving implant. The prevalence of PI, PIM, and BOP at the implant level were 14.00%, 20.00%, and 40.00%, respectively. There was no significant difference in the occurrence of PI and PIM between OLP patients and healthy controls.

CONCLUSIONS

Stabilized OLP is not considered a significant risk factor for peri-implant diseases. It is advised against placing implants or prostheses during the acute phase of the disease. Histopathological investigation to differentiate OLP from oral lichenoid dysplasia is crucial.

Effect of LED photobiomodulation on dental implant osseointegration: An in vivo study

Background

Photobiomodulation (PBM) may be prescribed after dental surgery to accelerate tissue healing and improve implant stability. The objective of this study is to evaluate the efficiency of LED-PBM on the dental implant osseointegration.

Methods

A total of 48 implants (KontactTM) were inserted in 8 Yucatan minipigs (6 implants per minipig) divided into 2 groups (test and control). The test group received LED-PBM with a total energy of 124.2 J/cm2 delivered over 4 sessions (at day0, day+8, day+15 and day+28) lasting 12 minutes each. At day+28, all animals were sacrificed, and their mandibles removed to perform histologic and histomorphometric analysis. Implant osseointegration was evaluated using the computation of bone/implant contact (BIC) index and bone surface/total surface (BS/ TS) ratio. The groups were compared using Student's unpaired t test.

Results

BIC index and BS/TS ratio were significantly higher within the test group as compared to the control group (P<0.01). Histologic observations on bone tissues demonstrated that LED-PBM may improve and accelerate dental implant osseointegration: 25% of dental implants analyzed within the test group were completely osseointegrated, versus 12.5% within the control group.

Conclusion

This experimental study indicates that LED-PBM contributes to enhancing implant treatment outcomes.

Osteoimmune regulation underlies oral implant osseointegration and its perturbation

In the field of biomaterials, an endosseous implant is now recognized as an osteoimmunomodulatory but not bioinert biomaterial. Scientific advances in bone cell biology and in immunology have revealed a close relationship between the bone and immune systems resulting in a field of science called osteoimmunology. These discoveries have allowed for a novel interpretation of osseointegration as representing an osteoimmune reaction rather than a classic bone healing response, in which the activation state of macrophages ((M1-M2 polarization) appears to play a critical role. Through this viewpoint, the immune system is responsible for isolating the implant biomaterial foreign body by forming bone around the oral implant effectively shielding off the implant from the host bone system, i.e. osseointegration becomes a continuous and dynamic host defense reaction. At the same time, this has led to the proposal of a new model of osseointegration, the foreign body equilibrium (FBE). In addition, as an oral wound, the soft tissues are involved with all their innate immune characteristics. When implant integration is viewed as an osteoimmune reaction, this has implications for how marginal bone is regulated. For example, while bacteria are constitutive components of the soft tissue sulcus, if the inflammatory front and immune reaction is at some distance from the marginal bone, an equilibrium is established. If however, this inflammation approaches the marginal bone, an immune osteoclastic reaction occurs and marginal bone is removed. A number of clinical scenarios can be envisioned whereby the osteoimmune equilibrium is disturbed and marginal bone loss occurs, such as complications of aseptic nature and the synergistic activation of pro-inflammatory pathways (implant/wear debris, DAMPs, and PAMPs). Understanding that an implant is a foreign body and that the host reacts osteoimmunologically to shield off the implant allows for a distinction to be drawn between osteoimmunological conditions and peri-implant bone loss. This review will examine dental implant placement as an osteoimmune reaction and its implications for marginal bone loss.

Dental Implant Treatment in Patients Suffering from Oral Lichen Planus: A Narrative Review

BACKGROUND

The aim of this study was to describe the complications and survival rates of dental implants placed in patients suffering from oral lichen planus (OLP) and to present recommendations for implant treatment in this group of patients through a narrative review of the published studies.

METHODS

A search of the literature was conducted using four databases: PubMed/Medline, Web of Science, Cochrane, and Scopus with a stop date of May 2022.

RESULTS

Eighteen studies were evaluated. The results showed that dental implant survival rates in patients with OLP were similar to those reported in the general population. Moreover, the existing literature seemed to imply that OLP is not a suspected risk factor for peri-implant diseases. However, patients suffering from erosive forms of OLP or desquamative gingivitis and poor oral hygiene were more susceptible to developing peri-implant diseases; in addition, oral squamous cell carcinoma was observed in a few cases of OLP.

CONCLUSION

With the limitations of this narrative review, dental implants may be regarded as a safe and feasible therapeutic approach to the treatment of patients with well-controlled OLP. These patients should be monitored carefully during follow-up care. Well-designed prospective trials are required to validate the present findings.

Long-term evaluation of the prognosis of super hydrophilic surface treated CA implants: a retrospective clinical study

BACKGROUND

This study was performed to evaluate the long-term clinical efficacy of the CA implants (Osstem Implant, Busan, Korea), calcium-modified surfaced treated implants on acid-etched surfaces sandblasted with alumina.

METHODS

From January 2013 to December 2015, 258 implants of 120 patients placed between 2013 and 2015 were retrospectively studied. Using medical records and periapical radiographs, sex, age, location, fixture width and length of placed implants, presence or absence of bone graft, types of bone substitutes and membrane used for bone grafting, primary and secondary stability, initial and delayed complications, and marginal bone loss were investigated. The success rate and survival rate of the implants in each group were analyzed retrospectively based on the criteria suggested by Albrektsson et al. RESULTS: Between 2013 and 2015, with a follow-up longer than 5 years, 258 implants with an average diameter of 4.63 mm (3.5-5.5 mm) and an average length of 9.94 mm (7.0-13.0 mm) were placed in a total of 120 patients (61 males and 59 females) with a mean age of 63.7 years for an average of 62 months of observation period. The survival rate was 97.3%, the success rate was 94.2%, and the average final marginal bone loss was 0.074 mm.

CONCLUSION

The CA implants manufactured with the improved surface treatment method exhibited a survival rate of 97.3% and a success rate of 94.2% over an average observation period of 62 months. The implants were not affected by most factors and had very high survival and success rates over a long period of observation. In particular, the stability of the implant was excellent, with no cases of failed implants in delayed placement after bone grafting and a healing period.

Stability of dental implants with sandblasted and acid-etched (SLA) and modified (SLActive) surfaces during the osseointegration period

Background. The surface properties of implants are effective factors for increasing the osseointegration and activity of osteoprogenitor cells. This study compared the stability of dental implants with sandblasted and acid-etched (SLA) and modified surfaces (SLActive) using the resonance frequency analysis (RFA). Methods. In a split-mouth design, 50 dental implants with either SLA surface properties (n=25) or modified (SLActive) surface properties (n=25) were placed in the mandibles of 12 patients with a bilateral posterior edentulous area. Implant stability was measured using RFA (Osstell) at implant placement time and every week for 1, 2, and 3 months before the conventional loading time. Results. One week following the implantation, implant stability increased from 70 to 77.67 for SLA and from 71.67 to 79 for SLActive (P < 0.05). Stability improved each week except in the 4th week in SLActive surface measurements. No significant differences were observed between the groups at 2 and 3 months (P > 0.05). Conclusions. For both implant surfaces, increased stability was observed over time, with no significant differences between the groups.

Influence of osteoporosis and mechanical loading on bone around osseointegrated dental implants: A rodent study

This study aimed to evaluate the influence of estrogen deficiency and mechanical loading on bone around osseointegrated dental implants in a rat jaw model. The maxillary right first molars of 36 rats were extracted. One week later, the rats were divided into an unloaded group and a loaded group; short head implants and long head implants were inserted respectively. Nine weeks after implantation, the rats were further subjected to ovariectomy (OVX) or sham surgery. All animals were euthanized 21 weeks after OVX. Micro-computed tomography, histological and histomorphometrical evaluation were undertaken. Systemic bone mineral density and bone volume fraction decreased in OVX groups compared with the sham controls. Histomorphometrical observation indicated that unloaded OVX group showed significantly damaged osseointegration and bone loss versus the loaded OVX group. Both the bone density (BD) inside the peri-implant grooves and the percentage of bone-to-implant contact (BIC) were lower in the OVX groups than in the sham-surgery groups, although mechanical loading increased the BIC and BD in the loaded OVX group compared with the unloaded OVX group. An increased number of positive cells for tartrate-resistant acid phosphatase was observed in the OVX groups versus the sham controls. The percentage of sclerostin-positive osteocytes was lower under loaded compared with unloaded conditions in both the OVX groups and the sham controls. In conclusion, estrogen deficiency could be a risk factor for the long-term stability of osseointegrated implants, while mechanical loading could attenuate the negative influence of estrogen deficiency on bone formation and osseointegration.

Multifunctional natural polymer-based metallic implant surface modifications

High energy traumas could cause critical damage to bone, which will require permanent implants to recover while functionally integrating with the host bone. Critical sized bone defects necessitate the use of bioactive metallic implants. Because of bioinertness, various methods involving surface modifications such as surface treatments, the development of novel alloys, bioceramic/bioglass coatings, and biofunctional molecule grafting have been utilized to effectively integrate metallic implants with a living bone. However, the applications of these methods demonstrated a need for an interphase layer improving bone-making to overcome two major risk factors: aseptic loosening and peri-implantitis. To accomplish a biologically functional bridge with the host to prevent loosening, regenerative cues, osteoimmunomodulatory modifications, and electrochemically resistant layers against corrosion appeared as imperative reinforcements. In addition, interphases carrying antibacterial cargo were proven to be successful against peri-implantitis. In the literature, metallic implant coatings employing natural polymers as the main matrix were presented as bioactive interphases, enabling rapid, robust, and functional osseointegration with the host bone. However, a comprehensive review of natural polymer coatings, bridging and grafting on metallic implants, and their activities has not been reported. In this review, state-of-the-art studies on multifunctional natural polymer-based implant coatings effectively utilized as a bone tissue engineering (BTE) modality are depicted. Protein-based, polysaccharide-based coatings and their combinations to achieve better osseointegration via the formation of an extracellular matrix-like (ECM-like) interphase with gap filling and corrosion resistance abilities are discussed in detail. The hypotheses and results of these studies are examined and criticized, and the potential future prospects of multifunctional coatings are also proposed as final remarks.

Occlusal Schemes for Implant Restorations: Best Evidence Consensus Statement

PURPOSE

Numerous studies have focused on the various complications with implant-retained restorations and a common thread in these publications is the potential for occlusal overload. The purpose of this Best Evidence Consensus Statement on implant occlusal schemes was to review the literature to determine the level of scientific evidence upon which the articles are based.

MATERIALS AND METHODS

Limiting the search to Clinical trials, Randomized Controlled Trials, Systematic Reviews, Meta-analyses, the key words: dental implants, occlusion, found no citations. Expanding the search to Journal articles found 1,483 results, 20 of which pertained to the question. Doing a similar search including Journal Articles, the key words: dental implants and occlusal scheme found 47 citations, 17 of which were pertinent to the question.

RESULTS

After eliminating duplicates and non-relevant articles, 15 were included in the review. Nineteen additional articles were culled by going through the reference lists in the aforementioned articles.

CONCLUSIONS

There is a lack of scientific evidence regarding the occlusal scheme utilized with implant restorations that will minimize or eliminate complications. In light of this lack of scientific evidence, the style of occlusion a practitioner utilizes with tooth or mucosal supported prostheses may be used with implant-supported restorations until compelling evidence dictates otherwise.

Oral Lichen Planus and Dental Implants: Protocol and Systematic Review

A systematic review was conducted to answer the following PICO question: “Can patients diagnosed with oral lichen planus (OLP) be rehabilitated with dental implants as successfully as patients without OLP?”. A systematic review of the literature was done following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statements to gather available and current evidence of oral lichen planus and its relationship with dental implants. The synthesis of results was performed using a Binary Random-Effects Model meta-analysis. Summary measures were odds ratios (ORs), frequencies, and percentages comparing the survival rate of dental implants placed in patients with OLP vs. those in patients without OLP. The electronic search yielded 25 articles, after removing the duplicated ones, 24 articles were selected. Out of the 24 articles, only 15 fulfilled the inclusion criteria. According to the results of the meta-analysis, with a total sample of 48 patients with OLP and 49 patients without OLP, an odds ratio of 2.48 (95% CI 0.34–18.1) was established, with an I² value of 0%. According to the Strength of Recommendation Taxonomy (SORT) criteria, level A can be established to conclude that patients with OLP can be rehabilitated with dental implants.

Biomimetic Properties of Engineered Periodontal Ligament/Cementum in Dental Implants

The conventional concept of osseointegrated dental implants based on direct connection to alveolar bone lacks a structured periodontal ligament (PDL) as in natural tooth. This limits the physiologic and functional efficiency of the implant in cushioning occlusal overload, orthodontic tooth movement, and proprioception. Development of bio-mimetic implants that can satisfy the bio-functional requirements of the natural tooth will be an innovative approach and preliminary researches in this area has been reported. This review includes in vivo studies which reported structural features and functional efficiency of an artificial PDL or cementum developed around dental implants. The electronic search identified 12 animal studies and one human trial which utilized retained or adjacent natural tooth roots, exogenous scaffold materials, dental progenitor cells derived from PDL of extracted tooth root as PDL substitutes. The result of the review is dominated by bio-hybrid implants that used dental follicles separated on the particular embryonic day and cell sheets from immortalized human cells. A summary of the currently available research on artificial PDL/cementum around dental implants highlights the potential need of autologous cell-derived tissues to bioengineer a fully functional implant design

Applying dental implant therapy in patients with oral lichen planus: a review of literature

Lichen planus (LP) is a violent, paranormal inflammatory disease that can affect the skin or any lining of the mucous membrane. LPs are a branch of immune-mediated inflammatory disease (IMID) that collaborates with the function and structure of the immune system that are precipitated through various etiological infectious agents. Oral lichen planus (OLP) is one of the most common kinds of IMID. These traumas might limit the normal life of patients and, in some cases, can be treated spontaneously. In patients who are affected by OLP, the dental clinicians must be capable of the proper diagnosis of the disorder. Dental implants are progressively applied for the treatment of partial or complete edentulism. Implant rehabilitation in OLP patients is one of the main challenges for patients and dental clinicians. There is not enough knowledge about this condition, and also medical documents are limited. In this study, by conducting a comprehensive review of literature, we tried to collect related data around the safety and success rate of implant rehabilitation in patients who suffer from OLP disorder. There proved to be no relation between implant survival rate and OLP diseases, but it is proven that some factors such as bone quality and fracture resistance, parafunctional habits, and resection of the marginal mandible could powerfully affect it. For evaluation of the advantages and disadvantages of applying implants in patients with OLP disorders, implementation of controlled studies is required.

The long-term evaluation of the prognosis of implants with acid-etched surfaces sandblasted with alumina: a retrospective clinical study

Background

The aim of this study was to evaluate the long-term clinical stability of implants with acid-etched surfaces sandblasted with alumina using retrospective analyses of the survival rate, success rate, primary and secondary stability, complications, and marginal bone loss of the implants.

Methods

Patients who had implants placed (TS III SA, SS II SA, SS III SA, and U III SA) with SA surfaces from Osstem (Osstem Implant Co., Busan, Korea) at the Seoul National University Bundang Hospital, from January 2008 to December 2010 were selected for the study. Patients’ medical records and radiographs (panorama, periapical view) were retrospectively analyzed to investigate sex, age, location of implantation, diameter, and length of the implants, initial and secondary stability, presence of bone grafting, types of bone grafting and membranes, early and delayed complications, marginal bone loss, and implant survival rate.

Results

Ninety-six implants were placed in 45 patients. Five implants were removed during the follow-up period for a total survival rate of 94.8%. There were 14 cases of complications, including 6 cases of early complications and 8 cases of delayed complications. All five implants that failed to survive were included in the early complications. The survival of implants was significantly associated with the occurrence of complications and the absorption of bone greater than 1 mm within 1 year after prosthetic completion. In addition, the absorption of bone greater than 1 mm within 1 year after prosthetic completion was significantly associated with the occurrence of complications, primary stability, and implant placement method. Five cases that failed to survive were all included in the early complications criteria such as infection, failure of initial osseointegration, and early exposure of the fixture.

Conclusions

Of the 96 cases, 5 implants failed resulting in a 94.8% survival rate. The failed implants were all cases of early complications such as infection, failure of initial osseointegration, and early exposure of the fixtures. Peri-implantitis was mostly addressed through conservative and/or surgical treatment and resulted in very low prosthetic complications. Therefore, if preventive measures are taken to minimize initial complications, the results can be very stable.

Dental Implants in Patients with Oral Lichen Planus: A Systematic Review

Background and Objectives: To integrate the available published data on patients with oral lichen planus (OLP) rehabilitated with dental implants, as well as to review the recommendations for OLP patients receiving implants. Materials and Methods: An electronic search was undertaken in February 2019 using five databases. Publications reporting cases of patients with OLP and rehabilitated with implant-supported oral prosthesis were included. Results: Twenty-two publications were included (230 patients, 615 implants). The overall implant failure rate was 13.9% (85/610). In patients with oral squamous cell carcinoma (OSCC) the failure rate was 90.6% (29/32), but none of these implants lost osseointegration; instead, the implants were removed together with the tumor. One study presented a very high implant failure rate, 76.4% (42/55), in patients with “active lichen planus”, with all implants failing between 7–16 weeks after implant placement, and its conflicting and incongruent results are discussed in detail. There was a statistically significant difference between the failure rates in implants installed in different jaws (maxilla/mandible) and when implants of different surfaces were used (turned/moderately rough), but not between patients with reticular or erosive OLP types, or between male and female patients. If OSCC patients and the cases of the latter study are not considered, then the failure rate becomes very low (2.7%, 14/523). The time between implant placement and failure was 25.4 ± 32.6 months (range 1–112). The mean ± SD follow-up was 58.9 ± 26.7 months (1–180). Conclusions: When the results of the one study with a very high failure rate and of the cases that developed OSCC are not considered, the dental implant failure rate in OLP patients was 2.7% after a follow-up of approximately five years. Recommendations are given when treating OLP patients with dental implants.

Removal of failed dental implants revisited: Questions and answers

Objectives

This narrative review is aiming on showing reasons for implant failure, removal techniques, and respective clinical considerations; further, the survival rate of implants in previous failed sites is examined.

Materials and methods

Questions have been formulated, answered, and discussed through a literature search including studies assessing implant failure and removal up to 2018.

Results

Studies describing reasons for implant failure, implant removal techniques, and the reinsertion of implants in a previous failed site (n = 12) were included. To date, peri-implantitis is the main reason for late implant failure (81.9%). Trephine burs seem to be the best-known method for implant removal. Nevertheless, the counter-torque-ratchet-technique, because of the low invasiveness, should be the first choice for the clinician. Regarding zirconia implant removal, only scarce data are available. Implantation in previously failed sites irrespective of an early or late failure results in 71% to 100% survival over 5 years.

Conclusion

If removal is required, interventions should be based on considerations regarding minimally invasive access and management as well as predictable healing. (Post)Operative considerations should primarily depend on the defect type and the consecutive implantation plans.

New Dental Implant with 3D Shock Absorbers and Tooth-Like Mobility-Prototype Development, Finite Element Analysis (FEA), and Mechanical Testing

Background: Once inserted and osseointegrated, dental implants become ankylosed, which makes them immobile with respect to the alveolar bone. The present paper describes the development of a new and original implant design which replicates the 3D physiological mobility of natural teeth. The first phase of the test followed the resistance of the implant to mechanical stress as well as the behavior of the surrounding bone. Modifications to the design were made after the first set of results. In the second stage, mechanical tests in conjunction with finite element analysis were performed to test the improved implant design. Methods: In order to test the new concept, 6 titanium alloy (Ti6Al4V) implants were produced (milling). The implants were fitted into the dynamic testing device. The initial mobility was measured for each implant as well as their mobility after several test cycles. In the second stage, 10 implants with the modified design were produced. The testing protocol included mechanical testing and finite element analysis. Results: The initial testing protocol was applied almost entirely successfully. Premature fracturing of some implants and fitting blocks occurred and the testing protocol was readjusted. The issues in the initial test helped design the final testing protocol and the new implants with improved mechanical performance. Conclusion: The new prototype proved the efficiency of the concept. The initial tests pointed out the need for design improvement and the following tests validated the concept.

Implant-based factor as possible risk for peri-implantitis

Peri-implantitis is currently a topic of major interest in implantology. Considered one of the main reasons of late implant failure, there is an emerged concern whether implant characteristics could trigger inflammatory lesion and loss of supporting bone. The purpose of this narrative review is to provide an evidence based overview on the influence of implant-based factors in the occurrence of peri-implantitis. A literature review was conducted addressing the following topics: implant surface topography; implant location; occlusal overload; time in function; prosthesis-associated factors (rehabilitation extension, excess of cement and implant-abutment connection); and metal particle release. Although existing data suggests that some implant-based factors may increase the risk of peri-implantitis, the evidence is still limited to consider them a true risk factor for peri-implantitis. In conclusion, further evidences are required to a better understanding of the influence of implant-based factors in the occurrence of peri-implantitis. Large population-based studies including concomitant analyses of implant- and patient-based factors are required to provide strong evidence of a possible association with peri-implantitis in a higher probability. The identification of these factors is essential for the establishment of strategies to prevent peri-implantitis.

The relationship between single nucleotide polymorphisms and dental implant loss: a scoping review

OBJECTIVES

The purpose of this review was to evaluate the relationship between genetic polymorphisms and dental implant loss.

MATERIALS AND METHODS

All case-control studies examining single nucleotide polymorphisms (SNPs) and dental implant failure were considered. A Boolean search was conducted on PubMed and Scopus to find eligible studies.

RESULTS

The initial search produced 78 results. Twenty-one studies were considered for inclusion after review and 16 were included in the final review. Twenty-two different polymorphisms were analyzed and statistically significant correlation was found for IL-4, IL-1A, IL-1B, MMP-8, and MMP-1 polymorphisms for dental implant failure.

DISCUSSION

A limited number of comprehensive studies have been done in this field. Additional studies with larger sample sizes and different ethnic backgrounds need to be done to see if the results can be reproduced. Of the polymorphisms studied, the IL-4 (+33), MMP-8 (-799), MMP-1 (-519), and MMP-1 (-1607) polymorphisms show the greatest association with dental implant loss.

Implants in patients with oral manifestations of autoimmune or muco-cutaneous diseases - A systematic review

BACKGROUND

To give an overview on implant survival rates in patients with oral manifestations of systemic autoimmune (oral Lichen planus (oLp), Pemphigus (Pe)), muco-cutaneous (Epidermolysis bullosa (EB)), autoimmune multisystemic rheumatic diseases (Sjögren's syndrome (SjS), systemic Lupus erythematosus (sLE), or systemic Sclerosis (sSc)).

MATERIAL AND METHODS

Systematic literature review (PubMed/Medline, Embase) using MESH and search term combinations, published between 1980 and August 2018 in English language reporting on dental implant-prosthetic rehabilitation of patients with oLp, Pe, EB, SjS, sLE, sSc, study design, age, gender, follow-up period (≥ 12 months), implant survival rate. Implant-related weighed mean values of implant survival rate (wmSR) were calculated.

RESULTS

After a mean follow-up period (mfp) of 44.6 months, a wmSR of 98.3 % was calculated from data published for patients with oLp (100 patients with 302 implants). Data of 27 patients (152 implants) with EB revealed wmSR of 98.7 % following mfp of 32.6 months. For 71 patients (272 implants) with SjS, wmSR was 94.2 % following a mfp of 45.2 months, and for 6 patients (44 implants) with sSc, wmSR was 97.7 % after mfp of 37.5 months. One case report on one patient each with Pe (two implants) as well as sLE (6 implants) showed 100 % SR following at least 24 months.

CONCLUSIONS

Guidelines regarding implant treatment of patients with oLp, Pe, EB, SjS, sLE or sSc do not exist nor are contraindicating conditions defined. Implant survival rates of patients affected are comparable to those of healthy patients. For implant-prosthetic rehabilitation of patients with Pe and sLE no conclusions can be drawn due to lack of sufficient clinical data. Implant-prosthetic treatment guidelines regarding healthy patients should be strictly followed, but frequent recall is recommended in patients affected with oLp, SjS, EB, SSc, Pe or sLE.

Comparative study of stress characteristics in surrounding bone during insertion of dental implants of three different thread designs: A three-dimensional dynamic finite element study

The objective of this study is to evaluate the stress distribution characteristics around three different dental implant designs during insertion into bone, using dynamic finite element stress analysis. Dental implant placement was simulated using finite element models. Three implants with different thread and body designs (Model 1: root form implant with three different thread shapes; Model 2: tapered implant with a double-lead thread; and Model 3: conical tapered implant with a constant buttress thread) were assigned to insert into prepared bone cavity models until completely placed. Stress and strain distributions were descriptively analyzed. The von Mises stresses within the surrounding bone were measured. At the first 4-mm depth of implant insertion, maximum stress within cortical bone for Model 3 (175 MPa) was less than the other models (180 MPa each). Stress values and concentration area were increasing whereas insertion depth increased. At full implant insertion depth, maximum stress level in Model 1 (35 MPa) within the cancellous bone was slightly greater than in Models 2 (30 MPa) and 3 (25 MPa), respectively. Generally, for all simulations, the highest stress value and the location of the stress concentration area were mostly in cortical bone. However, the stress distribution patterns during the insertion process were different between the models depending on the different designs geometry that contacted the surrounding bone. Different implant designs affect different stress generation patterns during implant insertion. A range of stress magnitude, generated in the surrounding bone, may influence bone healing around dental implants and final implant stability.

Influence of negative pressure wound therapy on peri-prosthetic tissue vascularization and inflammation around porous titanium percutaneous devices

Negative Pressure Wound Therapy (NPWT) has been shown to limit downgrowth around percutaneous devices in a guinea pig model. However, the influence of NPWT on peri-prosthetic tissue characteristics leading to limited downgrowth is still unclear. In order to investigate this, 12 CD hairless rats were assigned into two groups, NPWT and Untreated (n = 6/group). Each animal was implanted with a porous coated titanium percutaneous device and was dressed with a gauze and semi-occlusive base dressing. Post-surgery, animals in the NPWT Group received a regimen of NPWT treatment (-70 to -90 mmHg). After 4 weeks, tissue was collected over the device and stained with CD31 and CD68 to quantify blood vessel density and inflammation, respectively. The device with the surrounding tissue was also collected to quantify downgrowth. NPWT treatment led to a 1.6-fold increase in blood vessel densities compared to untreated tissues (p < 0.05). NPWT treatment also resulted in half the downgrowth as the Untreated Group, although not statistically significant (p = 0.19). Additionally, the results showed a trend toward increased CD68 cell densities in the NPWT Group compared to the Untreated Group (p = 0.09). These findings suggest that NPWT may influence wound healing responses in percutaneous devices by increasing blood vessel densities, limiting downgrowth and potentially increasing inflammation. Overall, NPWT may enhance tissue vascularity around percutaneous devices, especially in patients with impaired wound healing. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 2091-2101, 2019.

Dense cancellous bone as evidenced by a high HU value is predictive of late implant failure: a preliminary study

OBJECTIVES

The mechanism of late implant failure is unclear. This study examined the association between sclerosing cancellous bone images and the risk of late implant failures using multi-detector row computed tomography (CT) imaging data.

METHODS

We performed a case-control study. The study group consisted of consecutive patients with implant failures treated at Kyushu Dental University between 2001 and 2016. CT data for late failure of 36 implants in 16 patients were available. The study cohort consisted of 16 patients with 36 late failed implants and 28 patients with 113 successful implants.

RESULTS

The mean survival rate was 6.9 months for early implant failure, 76.6 months for late failure with marginal bone resorption, inflammation symptoms, and so-called peri-implantitis, and 95.0 months for late failure caused by implant fracture. The mean HU value for cases in the control group was 507 compared with 1231 for cases with late failure implants. Logistic regression was used for analysis. There were signs of high radiodensity of peri-implant cancellous bone when comparing adjusted radiodensity per 100 HU using CT data (OR 2.35; 95% CI 1.73-3.20; p < 0.001).

CONCLUSIONS

Within the limits of our study, the presence of high radiodensity and cancellous bone consolidation on imaging may be related to risk factors for late implant failure. Therefore, CT images of the host cancellous bone status for observation of visible sclerosis could be a useful diagnostic indicator for late implant failure.

Dental Implant Rehabilitation in Patients Suffering from Mucocutaneous Diseases: A Systematic Review and Meta-Analysis

Objective:

Dental implantations are widely used for oral rehabilitation of edentulous patients. Despite high success rate, there are some risk factors that have been associated with failures. Oral mucocutaneous diseases are one of these risk factors for implant insertion due to the immunosuppressive therapy.

There are limited studies that have dealt with the subject of dental implantology in oral mucosal disorders mainly with patients with oral lichenplanus, pemphigoid, pemphigus vulgaris, and systemic lupus erythematosus. In order to assess the result of implantations in such patients, we have reviewed the studies.

Materials and Methods:

We searched PubMed, Science Direct, and Cochrane databases for articles published from Jan 2000 to Dec 2017, using key search word “dental implants”, “oral lichen planus”, “pemphigoid”, “pemphigus vulgaris” and ”systemic lupus erythematosus”.

Results:

The random effects analysis result shows overall failure rates of 22% in patients with oral lichen planus. A systematic review revealed some failures that are not definitely related to these diseases.

Conclusion:

Due to the lack of adequate studies, a meta-analysis was only possible for oral lichen planus. Presently, there is no definite guideline regarding the placement of implant in patients suffering from mucocutaneous diseases; nevertheless, we should always consider that these patients are specific cases and need more attention in the first step of treatment and follow-ups. So there is a need to further clinical studies in order to evaluate more risk factors accurately and make a definitive conclusion.

Streptococcus anginosus Dental Implant-Related Osteomyelitis of the Jaws: An Insidious and Calamitous Entity

PURPOSE

We analyzed the data from a series of patients with dental implant-related suppurative osteomyelitis of the jaws (DIOMJ) due to Streptococcus anginosus.

PATIENTS AND METHODS

The medical records of all patients seen for osteomyelitis of the jaws from 2011 to 2016 were reviewed. The primary outcome variable was Streptococcus anginosus DIOMJ. Other variables included age, gender, smoking habits, associated comorbidities, dental implant localization, type of osteomyelitis, delay between dental implant placement and DIOMJ, microbiologic examination and antibiogram, antibiotherapy, type of surgery, and final outcome. Cases from previous reports of DIOMJ were also analyzed for comparison. Finally, descriptive statistics were computed.

RESULTS

A total of 26 patients had jaw osteomyelitis; in 6 patients (26%), jaw osteomyelitis had developed after dental implant placement. S. anginosus was found in 5 patients and Escherichia coli in 1. The osteomyelitis was located in the mandible and associated with a deep neck abscess in all cases. All the patients were women and were either smokers or had comorbidities affecting bone metabolism. In all 6 cases, the dental implants were removed, and several surgical debridement procedures (≥2) and prolonged antibiotherapy (average of 6 months) were needed. Of the 6 patients, 3 required a radical surgical reconstructive procedure with partial resection and bone grafting.

CONCLUSIONS

The present study demonstrated that Streptococcus anginosus DIOMJ is a particularly aggressive form of osteomyelitis that has a propensity to develop in the mandible of women in their 60s who are either smokers or have comorbidities.

Polydopamine deposition with anodic oxidation for better connective tissue attachment to transmucosal implants

BACKGROUND AND OBJECTIVE

Nowadays, most designs for the transmucosal surface of implants are machined-smooth. However, connective tissue adhered to the smooth surface of an implant has poor mechanical resistance, which can render separation of tissue from the implant interface and induce epithelial downgrowth. Modification of the transmucosal surface of implants, which can help form a good seal of connective tissue, is therefore desired. We hypothesized that anodic oxidation (AO) and polydopamine (PD) deposition could be used to enhance the attachment between an implant and peri-implant connective tissue. We tested this hypothesis in the mandibles of Beagle dogs.

MATERIAL AND METHODS

AO and PD were used to modify the transmucosal region of transmucosal implants (implant neck). The surface microstructure, surface roughness and elemental composition were investigated in vitro. L929 mouse fibroblasts were cultured to test the effect of PD on cell adhesion. Six Beagle dogs were used for the in vivo experiment (n = 6 dogs per group). Three months after building the edentulous animal model, four groups of implants (control, AO, PD and AO + PD) were inserted. After 4 months of healing, samples were harvested for histometric analyses.

RESULTS

The surfaces of anodized implant necks were overlaid with densely distributed pores, 2-7 μm in size. On the PD-modified surfaces, N1s, the chemical bond of nitrogen in PD, was detected using X-ray photoelectron spectroscopy. L929 developed pseudopods more quickly on the PD-modified surfaces than on the surfaces of the control group. The in vivo experiment showed a longer connective tissue seal and a more coronally located peri-implant soft-tissue attachment in the AO + PD group than in the control group (P < .05).

CONCLUSION

The modification of AO + PD on the implant neck yielded better attachment between the implant and peri-implant connective tissue.

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.

Sem and Fractography Analysis of Screw Thread Loosening in Dental Implants

Biological and technical failures of implants have already been reported. Mechanical factors are certainly of importance in implant failures, even if their exact nature has not yet been established. The abutment screw fracture or loosening represents a rare, but quite unpleasant failure. The aim of the present research is an analysis and structural examination of screw thread or abutment loosening compared with screw threads or abutment without loosening. The loosening of screw threads was compared to screw thread without loosening of three different implant systems; Branemark (Nobel Biocare, Gothenburg, Sweden), T.B.R. implant systems (Benax, Ancona, Italy) and Restore (Lifecore Biomedical, Chaska, Minnesota, USA). In this study broken screws were excluded. A total of 16 screw thread loosenings were observed (Group I) (4 Branemark, 4 T.B.R and 5 Restore), 10 screw threads without loosening were removed (Group II), and 6 screw threads as received by the manufacturer (unused) (Group III) were used as control (2 Branemark, 2 T.B.R and 2 Restore). The loosened abutment screws were retrieved and analyzed under SEM. Many alterations and deformations were present in concavities and convexities of screw threads in group I. No macroscopic alterations or deformations were observed in groups II and III. A statistical difference of the presence of microcracks were observed between screw threads with an abutment loosening and screw threads without an abutment loosening.

Correlation between Implant Stability Quotient (ISQ) with Clinical and Histological Aspects of Dental Implants Removed for Mobility

Dental implants are a successful treatment modality for missing teeth; however, failures do occur. These failures can occur early in the healing process after primary stability has been achieved at the time of implant placement, or after initial bone remodeling and new bone growth have taken place. The ability to detect implants that are failing or will fail is still not possible. The aim of the present study is to see if correlations exist between RFA values and histologic and histochemical evaluation of the human retrieved implants for failure. In a 5 year period, 37 root form implants were retrieved because of mobility and underwent histological examination. Thin ground sections were obtained from each implant. All the implants had been removed with a 5 mm trephine. In all cases a peri-implant radiolucency was present. Before implant retrieval, the implant stability was evaluated with Osstell (Integration Diagnostics AB, Gothenburg, Sweden). All the implants were not osseointegrated clinically and mobility was present. Radiographically, bone loss was observed around the implants and the mean ISQ values was 37 (+/- 2.7). A scarce inflammatory cell infiltrate was present in the connective tissue of some specimens. In about 10 percent of specimens, the epithelium tended to surround the total perimeter of the implant. These data suggest that implants with an ISQ<40 are irretrievably lost and there is no possibility to save them. A statistically significant correlation was found between an ISQ<36 and irretrievably failed implants.

Is dental implantation indicated in patients with oral mucosal diseases

Background/Aim: Dental implants are a reliable treatment choice for rehabilitation of healthy patients as well as subjects with several systemic conditions. Patients with oral mucosal diseases often exhibit oral mucosal fragility and dryness, erosions, blisters, ulcers or microstomia that complicate the use of removable dentures and emphasize the need for dental implants. The aim of the current study is to review the pertinent literature regarding the dental implantation prospects for patients with oral mucosal diseases. Material and Method: The English literature was searched through PubMed and Google Scholar electronic databases with key words: dental implants, oral mucosal diseases, oral lichen planus (OLP), epidermolysis bullosa (EB), Sjögren’s syndrome (SS), cicatricial pemphigoid, bullous pemphigoid, pemphigus vulgaris, scleroderma/systemic sclerosis, lupus erythematosus, leukoplakia, oral potentially malignant disorders, oral premalignant lesions, oral cancer and oral squamous cell carcinoma (SCC). Results: Literature review revealed dental implantation in patients with OLP (14 articles), EB (11 articles), pemphigus vulgaris (1 article), SS (14 articles), systemic sclerosis (11 articles), systemic lupus erythematosus (3 articles) and oral SCC development associated with leukoplakia (5 articles). No articles regarding dental implants in patients with pemphigoid or leukoplakia without SCC development were identified. Most articles were case-reports, while only a few retrospective, prospective or observational studies were identified. Conclusions: Dental implants represent an acceptable treatment option with a high success rate in patients with chronic mucocutaneous and autoimmune diseases with oral manifestations, such as OLP, SS, EB and systemic sclerosis. Patients with oral possibly malignant disorders should be closely monitored to rule out the development of periimplant malignancy. Further studies with long follow-up, clinical and radiographic dental data are required to predict with accuracy the outcome of dental implants in patients with oral mucosal diseases.

Molecular Analysis of Healing at a Bone-Implant Interface

While bone healing occurs around implants, the extent to which this differs from healing at sites without implants remains unknown. We tested the hypothesis that an implant surface may affect the early stages of healing. In a new mouse model, we made cellular and molecular evaluations of healing at bone-implant interfaces vs. empty cortical defects. We assessed healing around Ti-6Al-4V, poly(L-lactide-co-D,L,-lactide), and 303 stainless steel implants with surface characteristics comparable with those of commercial implants. Our qualitative cellular and molecular evaluations showed that osteoblast differentiation and new bone deposition began sooner around the implants, suggesting that the implant surface and microenvironment around implants favored osteogenesis. The general stages of healing in this mouse model resembled those in larger animal models, and supported the use of this new model as a test bed for studying cellular and molecular responses to biomaterial and biomechanical conditions.

Analysis of the distribution of stress and deformation in single implant-supported prosthetic units in implants of different diameters

Abstract Introduction When stress and strain levels in the bone-implant system exceed It's capacity, a mechanical fatigue occurs, resulting in collapse and loss of osseointegration. Objective Analyze biomechanical behavior in single implant-supported prosthesis with implants of different diameters in the posterior mandible. Material and method Three different finite element models of Cone-Morse implants with the same height were created, varying the diameter (3.3 mm, 4.1 mm and 4.8 mm). The mandibular first molar area was the location of the implant, with It´s component and overlying prosthetic crown. The jawbone was composed of cortical and cancellous bone. Refined mesh of 0.5 mm was created in the critical interfaces to be analyzed. The loading of the models was performed at the point of occlusal contact with an occlusal load of 400 N. Result Maximum stress and strain occurred in the cervical regions of the implants in all groups, either in the implants or in components as well as in the analysis of cortical bone. The greater the diameter, the lower the stress and strain found in the implant. The 3.3 mm group had the highest strain in peri-implant cortical bone, and the 4.1 mm group had the smallest deformation, significantly lower than in the 4.8 mm group. Conclusion Although the biggest implant diameter (4.8 mm) appears to have lower values of stress and strain, the group of intermediate implant diameter (4.1 mm) showed less deformation rate in the cortical peri-implant bone. Therefore it is concluded that the 4.1 mm implant platform presented a more biomechanically effective peri-implant bone maintenance.

Rescuing failed oral implants via Wnt activation

AIM

Implant osseointegration is not always guaranteed and once fibrous encapsulation occurs clinicians have few options other than implant removal. Our goal was to test whether a WNT protein therapeutic could rescue such failed implants.

MATERIAL AND METHODS

Titanium implants were placed in over-sized murine oral osteotomies. A lack of primary stability was verified by mechanical testing. Interfacial strains were estimated by finite element modelling and histology coupled with histomorphometry confirmed the lack of peri-implant bone. After fibrous encapsulation was established peri-implant injections of a liposomal formulation of WNT3A protein (L-WNT3A) or liposomal PBS (L-PBS) were then initiated. Quantitative assays were employed to analyse the effects of L-WNT3A treatment.

RESULTS

Implants in gap-type interfaces exhibited high interfacial strains and no primary stability. After verification of implant failure, L-WNT3A or L-PBS injections were initiated. L-WNT3A induced a rapid, significant increase in Wnt responsiveness in the peri-implant environment, cell proliferation and osteogenic protein expression. The amount of peri-implant bone and bone in contact with the implant were significantly higher in L-WNT3A cases.

CONCLUSIONS

These data demonstrate L-WNT3A can induce peri-implant bone formation even in cases where fibrous encapsulation predominates.

Evaluation of mammalian and bacterial cell activity on titanium surface coated with dicationic imidazolium-based ionic liquids

This work presents a new strategy to protect titanium surfaces against bacterial colonization and biofilm formation using dicationic imidazolium-based ionic liquid coatings.

Spectroscopic and microscopic investigation of the effects of bacteria on dental implant surfaces

The surface morphology and chemical composition of commercially pure titanium dental implants and healing abutments exposed in vitro or in vivo to oral bacteria were studied.

Histopathological spectrum of bone lesions associated with dental implant failure: osteomyelitis and beyond

Early or late post-implant placement complications are usually localized infectious/inflammatory processes and treated accordingly. If the healing process does not take place within a reasonable timeframe, the possibility of a pathologic process beyond localized infection/inflammation should be suspected. We describe a radiological/histopathological spectrum of bony lesions ranging from inflammatory to malignant lesions surrounding failed dental implants. Five cases of mandibular dental implant failure that clinically, radiologically and histopathologically appeared to be inflammatory processes are presented. The failure of the dental implants was immediate in two cases and late in the remaining three. The radiological features were essentially similar for all five, and they included radiolucent or mixed radiolucent-radiopaque lesions with poorly defined borders. Three lesions were limited to the area of the failed implant, while the other two extended to a large part of the mandible. The histopathological findings ranged from acute osteomyelitis and chronic osteomyelitis with features of a fibro-osseous-like lesion and occasional rimming of atypical osteoblasts to osteogenic sarcoma that was admixed with a component of osteomyelitis (diagnosis of the latter was achieved only after a series of biopsies). In-depth investigative procedures are imperative in order to establish an accurate diagnosis whenever the histopathological diagnosis is inconsistent with persisting clinical signs and symptoms in bone lesions associated with failed dental implants.

Cellular populations of periimplant tissues: cytological analysis with sulcular microbrushing

PURPOSE

Cellular populations of gingival crevicular fluid cytological analysis of integrated implants sites have been investigated by using sulcular cytological brushing, as a means of providing an objective and reproducible technique for monitoring periimplant tissue health.

MATERIALS AND METHODS

A total of 60 patients with osteointegrated implants bearing at least for 2 years were divided in 2 groups, A and B. Group A consisted of 30 subjects who presented scarce oral hygiene. In Group B, 30 subjects with a good oral hygiene were included.

RESULTS

Comparative analysis of the data obtained by sulcular microbrushing of the 2 groups put into evidence significative differences in the expression of the microbiological and the cytological parameters.

CONCLUSION

Clinical monitoring of parodontal and periimplant tissues makes use of several diagnostic tests ranging from clinical and radiological tests to biological assays. However, none of these techniques allows to evaluate periimplant tissue cytological status. This preliminary study suggested sulcular microbrushing might be a useful tool in the early diagnosis and in the micrological monitoring of peri-implantitis.

Occlusal overload and bone/implant loss

AIM

The aim of this search was to assess the biological consequences that overload might have on already osseointegrated oral implants through a systematic screening of the scientific literature.

METHOD

Detailed searches through PUBMED, OVID, EMBASE and LILACS databases were made. Articles published up to December 2011 and those reported on the clinical, radiographic and/or histological outcome of oral implants subjected to so-called overload were considered eligible for inclusion. Identified studies were assessed by one non-blinded reviewer according to well-defined inclusion and exclusion criteria. When doubt arose, the co-authors were counselled until final agreement was obtained. The PICO questions formulated was:"what is the effect of overload vs. no overload on bone/implant loss in clinically stable implants?"

RESULTS

The database searches as well as additional hand searching, resulted in 726 potentially relevant titles. Eventually, 16 clinical and 25 animal studies were considered relevant to the topic. After inclusion/exclusion criteria assessment, all clinical studies and all but three animal studies and one systematic review were considered at high risk of bias and excluded. The included animal studies did not reveal an association between overload and peri-implant bone loss in the absence of peri-implant inflammation, whereas in its presence, overload seemed to aggravate the peri-implant tissue breakdown.

CONCLUSIONS

The effect of implant overload on bone/implant loss in clinically well-integrated implants is poorly reported and provides little unbiased evidence to support a cause-and-effect relationship. The PICO question remained unanswered. At the animal level, "overload", mimicked by supra-occlusal contacts acting in an uninflamed peri-implant environment, did not negatively affect osseointegration and even was anabolic. In contrast, supra-occlusal contacts in the presence of inflammation significantly increased the plaque-induced bone resorption.

3D finite element analysis of changes in stress levels and distributions for an osseointegrated implant after vertical bone loss

PURPOSE

The effect of stress levels and distributions around the internal nonsubmerged type implants after vertical bone resorption was investigated in this study.

MATERIALS AND METHODS

An HSII implant was placed in 4 cylindrical alveolar bone models with differing degrees of thread exposures. The load applied to each implant was von Mises stress and principal stress, 250 N in axial direction and 30 degrees lateral pressure. The difference in the load between the bone and the connective portion of the implant was obtained using ANSYS analysis.

RESULTS

Bone loss in the cervical area of the implant was more obvious under lateral pressure. When more threads were exposed, bone level decreased and the maximum load applied on the fixture increased.

CONCLUSIONS

It was concluded that higher bone level has a biomechanical advantage with respect to stress concentration.

A 5-year retrospective clinical study of the Dentium implants

PURPOSE

The aim of this retrospective study was to evaluate cumulative survival rate (CSR) of Implantium implants followed for 5 years and association between risk factors and the CSR.

MATERIALS AND METHODS

A total of two hundred forty-nine Implantium Implants System (Dentium, Seoul, Korea) placed in ninety-five patients from 2004 to 2009 were investigated with several identified risk factors (sex, systemic disease, smoking, alchohol, reason of tooth loss, length, arch (maxilla or mandible), replace tooth type (incisor, canine, premolar or molar) Kennedy classification, prosthodontic type, prosthodontic design, opposite dentition, abutment type, occlusal material, occlusal unit, splint to tooth, cantilever, other surgery). Clinical examination (mobility, percussion, screw loosening, discomfort, etc.) and radiographic examination data were collected from patient records including all problems during follow-up period according to protocols described earlier. Life table analysis was undertaken to examine the CSR. Cox regression method was conducted to assess the association between potential risk factors and overall CSR.

RESULTS

Five of 249 implants were failed. Four of these were lost before loading. The 5-year implant cumulative survival rate was 97.37%. Cox regression analysis demonstrated a significant predictive association between overall CSR and systemic disease, smoking, reason of tooth loss, arch, Kennedy classification and prosthodontic design (P<.05). The screw related complication was rare. Two abutment screw fractures were found. Another complications of prosthetic components were porcelain fracture, resin facing fracture and denture fracture (n=19).

CONCLUSION

The 5-year CSR of Implantium implants was 97.37%. Implant survival may be dependent upon systemic disease, smoking reason of tooth loss, arch, Kennedy classification and prosthodontic design (P<.05). The presence of systemic diseases and combination of other surgical procedures may be associated with increased implant failure.

Fabrication of a maxillary implant retained overdenture using an existing subperiostal implant: a clinical report

Subperiosteal implants used to be prescribed to partially and fully edentulous patients to restore occlusion and esthetics prior to the emergence of the more successful endosseous implants that are used today. Because subperiosteal implants had a high incidence of failure, difficulty of placement, and post-operative complications, the use of subperiosteal implants declined significantly. However, some subperiostal implants placed 20-30 years ago still survive. Little information is available in the literature on how to treat patients whose subperiosteal implants still remain. This clinical case report thereby describes a treatment for a patient with a maxillary subperiosteal implant placed 23 years ago. The patient was offered a treatment option that included surgical implant removal, bone grafting and placement of endosseous implants to support a new maxillary overdenture. This treatment plan was not feasible due to the financial constraints of the patient and the complexity of the treatment. The patient chose a more conservative treatment plan, preserving the existing implant. The existing maxillary subperiosteal implant was restored with MICRO ERA attachments and a maxillary implant-retained overdenture was fabricated. The patient was satisfied with the esthetics and functional aspects of the treatment. No further peri-implant bone loss or other complications were found after a six-month recall. This clinical report suggests an alternative treatment plan for patients with existing subperiosteal implants that wish to avoid complex surgical procedures.