Factors Affecting the Survival Rate of Dental Implants: A Retrospective Study

Systemic Factors Affecting Prognosis in Periodontics: Part II

This study gives an insight into certain systemic conditions and factors such as nutrition, age, hematological disorders, hypertension, smoking, obesity, and metabolic syndrome that have a notable effect on the periodontium. The review highlights the importance of taking these factors into consideration in periodontal therapy and their impact on the prognosis of periodontal therapies. The other systemic factors are discussed in detail elsewhere in the special issue.

Combining sandblasting and pink anodisation of Ti implants as a promising method for improving fibroblast adhesion and immune response

This study examined the effect of combining the sandblasting and anodising of titanium alloys used in implants on the cell response and protein adsorption patterns. The titanium samples were divided into four groups depending on the surface treatment: machining (MC), pink anodisation (PA), sandblasting (MC04) and a combination of the last two (MC04 + PA). Their physicochemical properties were analysed by SEM/EDX, Raman, contact angle measurements and profilometry. In vitro responses were examined using human gingival fibroblastic (HGF) cells and THP-1 macrophages. Cytokine secretion, macrophage adhesion and gene expression were measured by ELISA, confocal microscopy and RT-PCR. Cell adhesion and collagen secretion were evaluated in HGF cultures. The adsorption of immune and regenerative proteins onto the surfaces was assessed employing nLC-MS/MS. MC04 + PA surfaces exhibited a change in the roughness, chemical composition and hydrophilicity of the material, showing more elongated HGF cells and a considerable increase in the area of cells exposed to the MC04 + PA surfaces. Moreover, cells cultured on MC04 + PA generally showed a reduction in the expression of proinflammatory genes (TNF-α, MCP-1, C5, NF-kB and ICAM-1) and an increase in the secretion of anti-inflammatory cytokines, such as IL-4. These results correlated with the proteomic data; we found preferential adsorption of proteins favouring cell adhesion, such as DSC1 and PCOC1. A considerable reduction in the adsorption of immunoglobulins and proteins associated with acute inflammatory response (including SAA4) was also observed. The study highlights the potential advantages of MC04 + PA surface treatment to modify dental implant abutments; it enhances their compatibility with soft tissues and reduces the inflammatory response.

The effect of compressive force in bone tissue induced by implants of different primary stabilities on macrophage polarization and bone regeneration

Dental implants with different primary stabilities give rise to distinct stress distributions at the implant-bone interface after placement and exert mechanical force on the cells in the bone tissue. This study aimed to investigate whether the mechanical forces in peri-implant bone participate in the body's immune response and influence macrophage polarization. Therefore, an in vivo rat implantation model with different primary implant stabilities was established. The osteoimmune response and macrophage polarization were investigated, and the osseointegration of the implants was evaluated. In an in vitro experiment, an external compressive force was applied to RAW264.7 cells, and the polarization phenotype was observed. MC3T3-E1 cells were cultured in macrophage-conditioned medium to investigate the regulatory effect of the macrophage-secreted cytokines on the osteogenic differentiation of osteoblasts. In vivo experimental results indicated that the primary stability of implants is positively correlated with the mechanical force. The osteoimmune response was significantly amplified by compressive force generated from implants. This compressive force first induced both M1 and M2 macrophage polarization and then accelerated the progression of the transition to M2 macrophages in the bone repair phase. In vitro, compressive force significantly upregulated the M1 and M2 macrophage polarization. In addition, the suppressive effect of macrophages on the osteogenesis of MC3T3 cells was relieved by cytokines secreted by macrophages under compressive force loading, which promoted their osteogenesis. Overall, these results clarify that compressive force from different primary stabilities is an important influencing factor regulating the osteoimmunne response and macrophage polarization in addition to maintaining the implant.

Three-Dimensional Finite Element Analysis of Stress Distribution in Dental Implant Prosthesis and Surrounding Bone Using PEEK Abutments

(1) Background: Polyetheretherketone (PEEK) has been used as an alternative to titanium in implant prosthetic systems, but its impact on stress distribution in implant systems needs to be investigated. This study aimed to compare the effect of polyetheretherketone (PEEK) and titanium abutments on implant prosthetic systems and the supporting bone using three-dimensional finite element analysis (FEA). (2) Methods: Three-dimensional finite element analysis was conducted using CATIA V5 and Abaqus V6.12 software to model mandibular first-molar implant systems with titanium and PEEK abutments. Under external loading conditions, finite element analysis was conducted for the stresses in the implant components and surrounding bones of each group. (3) Results: The implant fixture of the PEEK model exhibited the highest von Mises stress (VMS). The lowest VMS was observed in the abutment screw of the titanium model. Both implant systems demonstrated similar stress distributions and magnitudes in cortical and cancellous bones. (4) Conclusion: PEEK abutments show a similar stress distribution in the surrounding bone compared to titanium. However, PEEK absorbs the stresses within the implant system and exhibits the highest VMS values due to its low mechanical and physical properties. Therefore, PEEK abutments need improved mechanical properties for better clinical application.

Comparing Bone Graft Success, Implant Survival Rate, and Marginal Bone Loss: A Retrospective Study on Materials and Influential Factors

Bone grafting serves to restore the alveolar bone defect, providing adequate alveolar bone essential for long-term implant survival. This retrospective study aimed to evaluate the success rate of guided bone regeneration (GBR) bone grafting and investigate the survival rate of implants and the degree of marginal bone loss (MBL) around implants. Furthermore, the influence of confounding factors such as patient conditions, bone graft properties, and implant characteristics was assessed. This study was carried out on treatment outcomes of patients with implants between January 2007 and December 2016, using various graft materials, including autograft, allograft, and xenograft. In a mean follow-up of 70 months (range: 3-10 years), the overall success rate of bone graft (n = 80) was 100%, and the overall survival rate of implant (n = 107) was 97.2% (autograft: 100%, allograft: 100%, and xenograft: 92.9%; P = .03). Mean MBL up to 3 years after implant installation were similar among graft materials, with 0.84 ± 0.48 mm in autograft, 0.73 ± 0.42 mm in allograft, and 1.01 ± 0.59 mm in xenograft (P = .14). Posterior mandibular location had a significant influence on implant survival (P = .003). A significant association of MBL with several factors, including age >60 years (P = .03), both diabetes and hypertension (P = .02), without receiving adjunctive membrane (P = .04), loading within 3-6 months (P < .001), and screw-retained crown (P = .008), was confirmed. Our data substantiated that implant rehabilitation with GBR using autograft and allograft provides the most predictable results. The factors above should be carefully considered with xenograft to enhance long-term clinical outcomes.

Electric Current Application on Dental Implant Biofilms: Review

The prevalence of complications due to the presence of biofilms in dental implant surfaces and their relationship with peri-implant diseases, namely peri-implantitis, remain difficult problems to overcome. The information available about the application of electric current on dental implant biofilms; its parameters, namely current level, voltage and exposure time; and related effects are still not enough to understand which individual mechanisms are caused by this technique, culminating in the decrease or eradication of the biofilm. The purpose of this narrative review, based on a systematic search, is to understand the effect of electric current directly applied to biofilms present in dental implants and which parameters are used. For the systematic search, electronic databases including MEDLINE/PubMed, Scopus, and Web of Science, up to and including November 2023, were searched. Seven studies were included. A 12-item checklist was used to assess their methodological quality. All studies used direct/constant electric current; however, that use was not achieved by the same protocol/set-up. Parameters such as current, voltage, resistance, and actuation time were different in all studies. Monospecies and multi-species biofilm were used in the substrate made of titanium. The results indicate that the use of constant and alternating electric current directly applied to dental implant's surfaces is a promising way to treat problems related to biofilms and peri-implant diseases. Future trials, namely in vivo tests, are necessary to reveal all the potential of this treatment.

Prediction of lifespan and assessing risk factors of large-sample implant prostheses: a multicenter study

PURPOSE

This study aimed to analyze factors influencing the success and failure of implant prostheses and to estimate the lifespan of prostheses using standardized evaluation criteria. An online survey platform was utilized to efficiently gather large samples from multiple institutions.

MATERIALS AND METHODS

During the one-year period, patients visiting 16 institutions were assessed using standardized evaluation criteria (KAP criteria). Data from these institutions were collected through an online platform, and various statistical analyses were conducted. Risk factors were assessed using both the Cox proportional hazard model and Cox regression analysis. Survival analysis was conducted using Kaplan-Meier analysis and nomogram, and lifespan prediction was performed using principal component analysis.

RESULTS

The number of patients involved in this study was 485, with a total of 841 prostheses evaluated. The median survival was estimated to be 16 years with a 95% confidence interval. Factors found to be significantly associated with implant prosthesis failure, characterized by higher hazard ratios, included the 'type of clinic', 'type of antagonist', and 'plaque index'. The lifespan of implant prostheses that did not fail was estimated to exceed the projected lifespan by approximately 1.34 years.

CONCLUSION

To ensure the success of implant prostheses, maintaining good oral hygiene is crucial. The estimated lifespan of implant prostheses is often underestimated by approximately 1.34 years. Furthermore, standardized form, online platform, and visualization tool, such as nomogram, can be effectively utilized in future follow-up studies.

Zirconia Dental Implants Surface Electric Stimulation Impact on Staphylococcus aureus

Tooth loss during the lifetime of an individual is common. A strategy to treat partial or complete edentulous patients is the placement of dental implants. However, dental implants are subject to bacterial colonization and biofilm formation, which cause an infection named peri-implantitis. The existing long-term treatments for peri-implantitis are generally inefficient. Thus, an electrical circuit was produced with zirconia (Zr) samples using a hot-pressing technique to impregnate silver (Ag) through channels and holes to create a path by LASER texturing. The obtained specimens were characterized according to vitro cytotoxicity, to ensure ZrAg non-toxicity. Furthermore, samples were inoculated with Staphylococcus aureus using 6.5 mA of alternating current (AC). The current was delivered using a potentiostat and the influence on the bacterial concentration was assessed. Using AC, the specimens displayed no bacterial adhesion (Log 7 reduction). The in vitro results presented in this study suggest that this kind of treatment can be an alternative and promising strategy to treat and overcome bacterial adhesion around dental implants that can evolve to biofilm.

Proper Management of Amalgam Powder Embedded in the Alveolus

The presence of foreign bodies in the mandible is not listed as a risk factor or absolute contraindication for implant rehabilitation. However, possible complications caused by foreign bodies, such as infection and cyst formation, could lead to implant failure. The authors report a case of dental implant placed 4 months after the surgical removal of embedded amalgam in the mandibular alveolus using a trephine bur and bone grafting with mineralized freeze-dried bone allograft. Clinical and radiographic evaluations were performed at each appointment to assess factors such as pain, implant mobility, probing depth, and marginal bone loss around the implant. Within 3 years of implant placement, there were no clinical signs and symptoms and no obvious radiographic marginal bone loss. Dental implant installation appears to be safe following the elimination of foreign materials, so long as anatomic and biological factors and appropriate implant choice, are taken into consideration.

Evaluating the effect of functionally graded materials on bone remodeling around dental implants

OBJECTIVES

This study evaluates the potential for osseointegration and remodeling of customized dental implants made from Titanium-Hydroxyapatite Functionally Graded Material (Ti-HAP FGM) with optimized geometry, using the finite element method (FEM).

METHODS

The study utilized CT scan images to model and assemble various geometrical designs of dental implants in a mandibular slice. The mechanical properties of Ti-HAP FGMs were computed by varying volume fractions (VF) of hydroxyapatite (0-20%), and a bone remodeling algorithm was used to evaluate the biomechanical characteristics of the ultimate bone configuration in the peri-implant tissue.

RESULTS

The findings of the FEA reveal that osseointegration improves with changes in the density and mechanical properties of the bone surrounding Ti-HAP implants, which are influenced by the varying VF of hydroxyapatite in the FGM.

SIGNIFICANCE

Increasing the hydroxyapatite fraction improves osseointegration, and appropriate length and diameter selection of Ti-HAP dental implants contribute to their stability and longevity.

The cumulative survival rate of sandblasted, large-grit, acid-etched dental implants: a retrospective analysis

PURPOSE

This retrospective study aimed to assess the long-term cumulative survival rate of titanium, sandblasted, large-grit, acid-etched implants over a 10-year follow-up period and investigate the factors affecting the survival rate and change in marginal bone loss (MBL).

METHODS

The study included 400 patients who underwent dental implant placement at the Department of Periodontology of Seoul National University Dental Hospital (SNUDH) between 2005 and 2015. Panoramic radiographic images and dental records of patients were collected and examined using Kaplan-Meier analysis, Cox proportional hazards regression analysis, and multiple regression analysis to determine the survival rates and identify any factors related to implant failure and MBL.

RESULTS

A total of 782 implants were placed with a follow-up period ranging from 0 to 16 years (mean: 8.21±3.75 years). Overall, 25 implants were lost, resulting in a cumulative survival rate of 96.8%. Comparisons of the research variables regarding cumulative survival rate mostly yielded insignificant results. The mean mesial and distal MBLs were 1.85±2.31 mm and 1.59±2.03 mm, respectively. Factors influencing these values included age, diabetes mellitus (DM), jaw location, implant diameter, bone augmentation surgery, and prosthetic unit.

CONCLUSIONS

This study found that the implant survival rates at SNUDH fell within the acceptable published criteria. The patients' sex, age, DM status, implant location, implant design, implant size, surgical type, bone augmentation, and prosthetic unit had no discernible influence on long-term implant survival. Sandblasted, large-grit, acid-etched implants might offer advantages in terms of implant longevity and consistent clinical outcomes.

Effects of diameters of implant and abutment screw on stress distribution within dental implant and alveolar bone: A three-dimensional finite element analysis

Background/purpose

Few studies have investigated the effects of abutment screw diameter in the stress of dental implants and alveolar bones under occlusal forces. In this study, we investigated how variations in implant diameter, abutment screw diameter, and bone condition affect stresses in the abutment screw, implant, and surrounding bone.

Materials and methods

Three-dimensional finite element (FE) models were fabricated for dental implants with external hex-type abutments measuring 4 and 5 mm in diameter. The models also included abutment screws measuring 2.0 and 2.5 mm in diameter. Each implant model was integrated with the mandibular bone comprising the cortical bone and four types of cancellous bone. In total, 12 finite element models were generated, subjected to three different occlusal forces, and analyzed using FE software to investigate the stress distribution of dental implant and alveolar bone.

Results

Wider implants demonstrated lower stresses in implant and bone compared with standard-diameter implants. The quality of cancellous bone has a minimal impact on the stress values of the implant, abutment screw, and cortical bone. Regardless of occlusal arrangement or quality of cancellous bone, a consistent pattern emerged: larger abutment screw diameters led to increased stress levels on the screws, while the stress levels in both cortical and cancellous bone showed comparatively minor fluctuations.

Conclusion

Wider implants tend to have better stress distribution than standard-diameter implants. The potential advantage of augmenting the abutment screw diameter is unfavorable. It may result in elevated stresses in the implant system.

An epidemiological qualitative/quantitative SWOT-AHP analysis in order to highlight the positive or critical aspects of dental implants: A pilot study

OBJECTIVES

In recent years, dental implants are increasing in popularity due to their high success rate, demonstrated functionality, and aesthetic treatment results. Scientific research is very active in proposing improvements in the quality and survival of implants, taking into consideration various aspects. The objective of this study was to provide a holistic epidemiologic view of the state of dental implants, using a systematic approach based on a multimethod SWOT (Strengths, Weaknesses, Opportunities, and Threats) analysis and AHP (analytical hierarchical process) qualitative-quantitative analysis to identify the characteristics that can determine their success or failure.

MATERIALS AND METHODS

The study used the hybrid method of SWOT-AHP.

RESULTS

Analysis of the results showed that among strengths, the skill of the dentist was considered the most important factor, followed by the success of dental implants in the old people; among weaknesses, bruxism and chronic diseases were highlighted; for opportunities, biomechanical behavior, in terms of good mechanical strength and good tribological resistance to chemical and physical agents in the oral cavity, were considered the most important factors; finally, among threats, medical liability and biomechanical problems had equal weight.

CONCLUSIONS

This study applied a multimethod SWOT-AHP approach to bring out favorable or critical evidence on the topic of dental implants. In accordance with the result of the strategic vector identified in the Twisting zone Adjustment type section, showed that implant surgery is a widespread technique but always needs improvement to increase the likelihood of success and reduce the complications that can lead to implant failure.

Effect of crown retention systems and loading direction on the stress magnitude of posterior implant-supported restorations: A 3D-FEA

This study aimed to investigate the effect of four retention systems for implant-supported posterior crowns under compressive loading using three-dimensional finite element analysis. A morse-taper dental implant (4.1 × 10 mm) was designed with Computer Aided Design software based on non-uniform rational B-spline surfaces. According to International Organization for Standardization 14,801:2016, the implant was positioned at 3 mm above the crestal level. Then four models were designed with different crown retention systems: screw-retained (A), cement-retained (B), lateral-screw-retained (C), and modified lateral-screw-retained (D). The models were imported to the analysis software and mesh was generated based on the coincident nodes between the juxtaposed lines. For the boundary conditions, two loads (600 N) were applied (axial to the implant fixture and oblique at 30°) totaling 8 conditions according to retention design and loading. The von-Mises stress analysis showed that different retention systems modify the stress magnitude in the implant-supported posterior crown. There is a similar stress pattern in the implant threads. However, models C and D presented higher stress concentrations in the crown margin in comparison with A and B. The oblique loading highly increased the stress magnitude for all models. In the simulated conditions, part of the stress was concentrated at the lateral screw under axial loading for model C and oblique loading for model D. The results indicate a possible new failure origin for crown retained using lateral screws in comparison to conventional cement-retained or screw-retained systems.

Do dental implants installed in different types of bone (I, II, III, IV) have different success rates? A systematic review and meta-analysis

Purpose

The objective of this systematic review and meta-analysis was to evaluate the survival rate of implants installed in bone type IV (Lekholm and Zarb, 1995) compared to that of implants installed in bone types I, II, and III.

Material and methods

This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA) and was registered in the PROSPERO International Database of Systematic Reviews (CRD42021229775). The PubMed/MEDLINE, Scopus, and Cochrane databases were searched through July 2021. The PICO question was: "Dental implants installed in type IV bone have a lower success rate when compared to implants installed in type I bone, II and III?". The established inclusion criteria were: 1) controlled and randomized clinical trials (RCT), 2) prospective and retrospective studies with at least 10 participants with dental implants, and 3) patients with dental implants installed in bone tissue types I, II, III, and IV (Lekholm and Zarb, 1985). The minimum followup duration was 1 year.

Results

After searching the identified databases, 117 articles were selected for full reading and 68 were excluded. Thus, 49 studies were included for qualitative and quantitative analyses. The total number of participants included was 12,056, with a mean age of 41.56 years and 29,905 implants installed. Bone types I, II, and III exhibit a lower implant failure rate when compared to bone type IV.

Conclusion

Dental implants installed in bone types I, II, and III showed significantly higher survival rates than those installed in type IV. The bone type I success rate was not significantly different than that of type II; however, the success rate of bone type I and II was higher than that of type III.

Patient-reported outcome measures and clinical performance of implant-retained mandibular overdentures with stud and ball attachments: A systematic review and meta-analysis

STATEMENT OF PROBLEM

Evidence regarding the retention system for a mandibular overdenture is important for treatment planning. However, the clinical performance of stud and ball attachments for mandibular overdenture retainers is unclear.

PURPOSE

The purpose of this systematic review and meta-analysis was to compare the clinical performance and self-reported patient outcomes of ball and stud attachments as mandibular overdenture retainers.

MATERIAL AND METHODS

Randomized (RCTs) and nonrandomized (N-RCTs) controlled clinical trials were selected based on the eligibility criteria. The risk of bias was assessed by using the Cochrane Collaboration Tools, and the certainty of the evidence (COE) by using the grades of recommendation, assessment, development, and evaluation (GRADE) workshop approach. Meta-analyses according to the follow-up period were performed for implant survival, prosthetic maintenance and complications, bleeding on probing (BoP), marginal bone loss (MBL), satisfaction, and oral health-related quality of life (OHRQoL).

RESULTS

Thirteen RCTs and 4 N-RCTs were included. Twelve studies presented a high risk of bias. The stud demonstrated a lower risk ratio (RR) (P<.001) for maintenance and complications concerning the need for matrix activation (RR 7.12 [2.65, 19.15]) (very low COE) and new overdentures (RR 2.47 [1.02, 5.96]) (moderate COE), ranging from 1 to 5 years of follow-up. Mean difference (MD) for MBL after 1 (MD 0.40 [0.28, 0.52]; P<.001) and 5 years (MD 0.18 [0.16, 0.20]; P<.001) was higher for ball attachments than that for stud (very low COE) attachments. Stud attachments also improved satisfaction (P<.001) when compared with ball attachments (very low COE). Implant survival rate (high COE), BoP (very low COE), and OHRQoL (low COE) were similar for the attachments.

CONCLUSIONS

Stud and ball attachments are clinically appropriate options as mandibular overdenture retainers and are capable of restoring OHRQoL. Nevertheless, the stud showed greater improvement in satisfaction and less prosthetic aftercare and MBL.

Impact of Vitamin D on Osseointegration in Dental Implants: A Systematic Review of Human Studies

This systematic review evaluates the impact of Vitamin D levels on dental implant osseointegration, hypothesizing that optimal Vitamin D enhances success rates, and aims to synthesize data on its relationship with clinical outcomes in implantology. A comprehensive search across PubMed, Cochrane Library, and Web of Science databases included seven peer-reviewed articles meeting the criteria for the review. These studies, conducted between 2008 and 2021, included human subjects and explicitly correlated serum Vitamin D levels with dental implant outcomes, following PRISMA guidelines. The selected studies involved 1462 participants and examined 4450 dental implants. Key findings included a varied implant loss rate ranging from 3.9% to 11.4% across the studies. One study reported a 9.8% implant loss rate, yet found no significant association between Vitamin D receptor polymorphism and implant success. Another study indicated successful implantation following Vitamin D3 supplementation, even in severe deficiency cases. The highest implant loss rate (11.1%) was observed in severely Vitamin D-deficient patients, particularly when compounded by risk factors such as smoking and periodontal disease. Additionally, one study noted significantly improved bone density following post-surgical Vitamin D supplementation for up to 12 weeks. The review supports a link between sufficient Vitamin D levels and successful dental implant osseointegration, suggesting Vitamin D deficiency as a potential risk factor for increased failure and advocating for Vitamin D evaluations in pre-surgical planning to potentially enhance implantology outcomes.

Comparison of crestal bone loss and papilla fill after conventional and immediate implant placement: A 12 month clinical and radiographic prospective study

Background

The problem of missing teeth persists in all age groups. The main objective of implants in dentistry is to provide a restoration that reconstructs the shape and restores esthetics and functions of edentulous areas. The objectives of this study are to compare the crestal bone level changes and papillary fill after placement of implants in fresh extraction socket, i.e. immediate implant placement, and healed extraction socket, i.e. delayed or conventional implant placement, and to assess other clinical parameters such as modified plaque index (mPI), modified gingival index (mGI) and gingival biotype in between the groups and within the groups.

Methods

18 patients were recruited in the study out of which 9 patients received implants as per immediate implant placement protocol (group 1) and 9 patients received implants as per conventional implant placement protocol (group 2). All patients were evaluated for gingival biotype, mPI and mGI and papillary fill was assessed as per Jemt's papilla score as clinical parameters. Implant site was assessed for radiographic bone loss using Image J software. Statistical analysis was performed using independent t test, paired t test and chi square test.

Results

At the end of 1 year, results showed that crestal bone loss was seen more in the immediate group than the conventional group. Conventional implants showed better papillary fill than implants placed in fresh extraction sockets. Plaque scores were assessed as per modified plaque index, which showed better results in the conventional group. Modified gingival index was used to assess gingival status which showed better results in the immediate group one year later.

Conclusions

Findings from the study suggest that crestal bone loss was found to be increased in the immediate group than the conventional group and papillary fill was better in the conventional group than the immediate group.Registration: CTRI ( CTRI/2019/09/021340).

Comparison of Alveolar Bone Level around Osseointegrated Dental Implants among Premenopausal and Postmenopausal Women: A 2-Year Study

The success of dental implants is affected by bone quality and quantity at the dental implant site. The present study was done to assess the changes in alveolar bone level around osseointegrated dental implants over a period of 2 years among the premenopausal and postmenopausal women. This prospective clinical study was conducted among 50 female patients who reported between January 2020-June 2020 and had a single missing molar in maxillary or mandibular arch. Patients were categorized into 2 groups: premenopause patients (Group A; n = 25) and postmenopause patients (Group B; n = 25). Marginal bone loss (MBL) was recorded at baseline, 12 mo and 24 mo follow-up and compared between both the groups using independent t-test. ANOVA was done to compare MBL between different time periods. On intragroup comparison, a statistically significant difference was observed between different time periods in both Group A (P = 0.05) and Group B (P = 0.04). Also, on intergroup comparison, a statistically significant difference was observed in Group B from Group A at 12 mo and 24 mo (P < 0.05). Increase in marginal bone loss was observed among postmenopausal women. Therefore, clinicians should emphasize the need for oral hygiene maintenance among postmenopausal women for peri-implant health.

How Can Imbalance in Oral Microbiota and Immune Response Lead to Dental Implant Problems?

Dental implantology is one of the most dynamically developing fields of dentistry, which, despite developing clinical knowledge and new technologies, is still associated with many complications that may lead to the loss of the implant or the development of the disease, including peri-implantitis. One of the reasons for this condition may be the fact that dental implants cannot yield a proper osseointegration process due to the development of oral microbiota dysbiosis and the accompanying inflammation caused by immunological imbalance. This study aims to present current knowledge as to the impact of oral microflora dysbiosis and deregulation of the immune system on the course of failures observed in dental implantology. Evidence points to a strong correlation between these biological disturbances and implant complications, often stemming from improper osseointegration, pathogenic biofilms on implants, as well as an exacerbated inflammatory response. Technological enhancements in implant design may mitigate pathogen colonization and inflammation, underscoring implant success rates.

Limited Evidence Suggests That Increased Frequency Of Daily Cigarette Smoking Might Be Associated With A Minor Increase In The Peri-Implant Bone Loss

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION

Afshari Z, Yaghini J, Naseri R. Levels Of Smoking and Peri-Implant Marginal Bone Loss: A Systematic Review And Meta-Analysis. J. Evid.-Based Dent. Pract. 2022;22(3):101721.           SOURCE OF FUNDING: None reported.

TYPE OF STUDY/DESIGN

Systematic review with meta-analysis of data (SRM).

Effectiveness, Esthetics, and Success Rate of Dental Implants in Bone-Grafted Regions of Cleft Lip and Palate Patients: A Systematic Review and Meta-Analysis

Congenital clefts impair function and appearance, thus impacting a patient's social and mental health. A multidisciplinary team that can offer comprehensive treatment from infancy through maturity and beyond can successfully address these abnormalities. Dental rehabilitation is very important for these patients; these abnormalities should be identified and must be treated accordingly. Hence it is of utmost importance to know the success rate and changes in quality of life from patient satisfaction in order to plan future treatment goals when coming across such cases. The aim of this article is to determine success rate, esthetics, and patient satisfaction in implant-based oral rehabilitation in bone-grafted regions of cleft patients. Registration was carried out in PROSPERO (International Prospective Register of Systematic Review) with registration number CRD42022329861 on May 7, 2022. Medical Subject Headings (MeSH) terms such as cleft lip, cleft palate, survival rate, and dental implants were used to handpick articles via an electronic database. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed to compile all the data gathered from an electronic database. According to the collected data, 93.5% of the survival rate with dental implants was noted irrespective of the type of bone grafts used. Also, improvement in quality of life was achieved in these patients. Effectiveness, esthetics, and success rate are very well achievable with implants in cleft patients. Although the aesthetics are not equivalent to that of dental implants in normal patients, patient satisfaction is still satisfactory in patients with dental implants in bone-grafted regions of cleft lip and palate.

Rhamnolipid 89 Biosurfactant Is Effective against Streptococcus oralis Biofilm and Preserves Osteoblast Behavior: Perspectives in Dental Implantology

Biofilm-related peri-implant diseases represent the major complication for osteointegrated dental implants, requiring complex treatments or implant removal. Microbial biosurfactants emerged as new antibiofilm coating agents for implantable devices thanks to their high biocompatibility. This study aimed to assess the efficacy of the rhamnolipid 89 biosurfactant (R89BS) in limiting Streptococcus oralis biofilm formation and dislodging sessile cells from medical grade titanium, but preserving adhesion and proliferation of human osteoblasts. The inhibitory activity of a R89BS coating on S. oralis biofilm formation was assayed by quantifying biofilm biomass and microbial cells on titanium discs incubated up to 72 h. R89BS dispersal activity was addressed by measuring residual biomass of pre-formed biofilms after rhamnolipid treatment up to 24 h. Adhesion and proliferation of human primary osteoblasts on R89BS-coated titanium were evaluated by cell count and adenosine-triphosphate quantification, while cell differentiation was studied by measuring alkaline phosphatase activity and observing mineral deposition. Results showed that R89BS coating inhibited S. oralis biofilm formation by 80% at 72 h and dislodged 63-86% of pre-formed biofilms in 24 h according to concentration. No change in the adhesion of human osteoblasts was observed, whereas proliferation was reduced accompanied by an increase in cell differentiation. R89BS effectively counteracts S. oralis biofilm formation on titanium and preserves overall osteoblasts behavior representing a promising preventive strategy against biofilm-related peri-implant diseases.

Is dynamic computer-assisted surgery more accurate than the static method for dental implant placement? A systematic review and meta-analysis

STATEMENT OF PROBLEM

Dynamic computer-assisted surgery for dental implant placement has become popular, but systematic comparisons of the accuracy of computer-assisted surgery with static surgery are lacking.

PURPOSE

The purpose of this systematic review and meta-analysis was to determine evidence on the difference in the accuracy of dynamic computer-assisted surgery compared with the static method for dental implant placement.

MATERIAL AND METHODS

A systematic search was conducted in 3 electronic databases: PubMed, Ovid, and Cochrane. Studies conducted on dental implants that compared the accuracy of positioning implants with a dynamic system with that of a static system were included. Randomized clinical trials, prospective and retrospective cohort studies, and in vitro studies were included in the review. Review articles, case reports, letters, opinion articles, commentaries, and nonpeer-reviewed literature were excluded.

RESULTS

Of the 26 full-text articles, 14 fulfilled the inclusion criteria. Of these, 2 were randomized clinical trials, 2 were prospective studies, and 1 was a retrospective cohort study. The remaining 9 were in vitro studies. A total of 1633 implants were placed with the static and 902 with the dynamic method. A significant mean difference (-0.51 degrees [95% CI: -0.90, -0.13]) between dynamic and static systems was only observed in the angular deviation of in vitro studies (P=.009). Meta-analysis was performed using Review Manager statistical software and forest plots were generated.

CONCLUSIONS

A difference was found in the angular deviation of implants placed with the dynamic approach compared with the static system. The dynamic system was better, but this difference was not demonstrable in clinical studies. No significant difference was found in the apical and coronal deviations of the dynamic and static systems.

Is Online Patient-Centered Information About Implant Bone Graft Valid?

Background A dental implant is one of the most commonly used treatments to replace missing teeth. A reasonable number of implant cases necessitate using a bone graft before or at the time of implant placement. This study aims to evaluate the quality and readability of online patient-centered information about implant bone grafts. Methodology This cross-sectional study used Google, Yahoo, and Bing search engines. The keywords were entered to screen 900 websites. The DISCERN, Journal of the American Medical Association (JAMA), and Health on the Net (HON) code tools evaluated the included websites for quality. The Flesch reading-ease score (FRES), Flesch-Kincaid grade level, and simple measure of gobbledygook tests measured readability. Statistical analysis was done using SPSS version 25 (IBM Corp., Armonk, NY, USA). Results A total of 161 websites were included; 65 (40.4%) of the included websites belonged to a university or medical center. Only five (3.1%) websites were exclusively related to dental implant treatments. DISCERN showed moderate quality for 82 (50.9%) websites. There was a statistical difference between commercial and non-profit organization websites. In the JAMA evaluation, currency was the most commonly achieved in 67 (41.6%) websites. For the HON code, four (2.5%) websites were certified. Based on FRES, the most common readability category was "fair difficult," accounting for 64 (39.8%), followed by "standard" in 56 (34.8%) websites. Conclusions The study findings suggest that English-language patient-centered information about implant bone grafts is challenging to comprehend and of low quality. Hence, there is a need to establish websites that provide trustworthy, high-quality information on implant bone grafts.

Is Corticalization in Radiographs Related to a Higher Risk of Bone Loss around Dental Implants in Smoking Patients? A 5-Year Observation of Radiograph Bone-Texture Changes

BACKGROUND

Currently, the topic of dental implants is widely researched. However, still compromising are the factors that can affect implant loss as a consequence of marginal bone loss. One of the factors is smoking, which has a devastating effect on human health and bone structure. Oral health and jaw condition are also negatively affected by smoking. The aim of this study was to evaluate the peri-implant jawbone corticalization phenomenon in tobacco smokers.

METHODS

A total of 2196 samples from 768 patients with an implant in the neck area were checked, and texture features were analyzed. The corticalization phenomenon was investigated. All analyses were performed in MaZda Software. The influence of corticalization was investigated as a factor on bone structure near the implant neck. The statistical analysis included a feature distribution evaluation, mean (t-test) or median (W-test) comparison, analysis of regression and one-way analysis of variance or Kruskal-Wallis test as no normal distribution or between-group variance was indicated for the significant differences in the investigated groups. Detected differences or relationships were assumed to be statistically significant when p < 0.05.

RESULTS

The research revealed that MBL was correlated with smoking after 5 years (0.42 mm ± 1.32 mm 0 mm ± 1.25 mm), the Corticalization Index was higher in the smoker group on the day of surgery, and it became higher after 5y of observation (185.98 ± 90.8 and 243.17 ± 155.47). The implant-loss frequency was higher in the group of smokers, too, compared to non-smokers (6.74% and 2.87%). The higher the torque value during the implant placement, the higher the Corticalization Phenomenon Index.

CONCLUSIONS

The research revealed a correlation between smoking and changes in bone structure in radio textures near the implants. The corticalization phenomenon is important, may be detected immediately after implant placement and may be one of the indicators of the implant success rate.

Cone-Beam Computed Tomography (CBCT)-Based Assessment of the Alveolar Bone Anatomy of the Maxillary and Mandibular Molars: Implication for Immediate Implant Placement

Purpose This study aims to examine specific aspects of socket morphology, including buccal and palatal/lingual bone width, interradicular bone (IRB) width, and assessments of root apices and furcation proximity to the vital structures of the maxillary and mandibular first and second molars using cone-beam computed tomography (CBCT). Materials and methods The study involved the analysis of 400 maxillary and mandibular first and second molars. Various measurements were taken to assess socket morphology, including mesiodistal (MD) and buccolingual (BL) width, buccal and lingual bone thickness at 2 mm apical to the alveolar crest, IRB width at 2 mm from the furcation, and the distance between the root apices and furcation to vital structures, such as the floor of the maxillary sinus (FMS) and inferior alveolar nerve (IAN). Results The mesiobuccal (MB) root of the second molar commonly intruded into the sinus, followed by the palatal root of the maxillary first molar. The mean FMS-F distance was 7.17 + 3.98 mm, and it was 7.2 + 2.72 mm for maxillary first and second molars, respectively. The mean IRB width was 2.77 + 0.96 and 2.29 + 0.74 mm for the first and second molars. The mandibular second molar had the shortest distance to the IAN in comparison to the first molar. For maxillary teeth, 7% of the first and 4% of the second molars presented alveolar anatomy adequate for immediate implant placement, compared to 84% and 50% of mandibular first and second molars. Conclusion Understanding the local alveolar bone anatomy of molars and its relationship to vital structures is crucial for the effective planning of implant treatments.

A Retrospective Analysis to Assess the Reasons for the Failure of Dental Implants

Background

To assess the reasons for dental implant failures.

Materials and Methods

A total of 100 implants were studied in 80 subjects. The radiographic investigations were performed to assess the record length of implant and diameter of implant. Risk factors, such as habit of smoking, history of diabetes, and hypertension, were recorded. The data were collected and assessed using Statistical Package for the Social Sciences (SPSS) software. The one-way analysis of variance (ANOVA) test was used to assess the failure rate in dental implants. A P-value less than 0.05 was considered statistically significant.

Results

A total of 100 dental implants were included. The maximum dental implant failure was seen with a diameter <3.75 mm (30%) followed by 3.75-4.5 mm (16%) and >4.5 mm (6.15%). The difference was found to be significant (P < 0.05).

Conclusion

Dental implant failure was high in dental implants with <3.75 mm diameter, dental implants with a length <10.0 mm, and among smokers.

Use of Systemic Steroids, Hormone Replacement Therapy, or Oral Contraceptives Is Associated with Decreased Implant Survival in Women

BACKGROUND

Systemic steroids, such as prednisone, hormonal replacement therapies, or oral contraceptives, are commonly prescribed to women who might also be receiving dental implant therapy. However, the effect of these medications on dental implant survival is unknown.

METHODS

The medical and dental records of individuals with dental implants (N = 1480 implants) who visited a postgraduate periodontics clinic between 2000 and 2017 were initially considered. Those younger than 21 years old, pregnant, or male were excluded according to the study's exclusion criteria. The presence of systemic diseases and conditions was assessed. Implant failure rates among female patients using systemic steroids, hormone replacement therapy, or oral contraceptives were compared with failure rates among patients not taking those medications.

RESULTS

The implant failure rate for the 65 implants in patients taking steroid medications was 7.69%; the failure rate for the 712 implants in patients not taking steroids was 1.54% (p < 0.001). After adjusting for smoking and the presence of diabetes, that relationship persisted, with an 8.47% implant failure rate for the 59 implants in patients taking steroids (vs. 1.54% failure for the 585 implants in patients not taking steroids; p < 0.001). Regression analyses demonstrated that the odds of implant failure versus success were 5.31 times greater in patients taking systemic steroids, hormone replacement therapy, or oral contraceptives (p < 0.05). No statistically significant differences in patient plaque control were found between the experimental and control groups.

CONCLUSIONS

Among women, the use of systemic steroids is associated with a five-fold increase in the rate of dental implant failure, regardless of the presence of smoking or diabetes.

Inter-implant distance and buccal bone thickness for a novel implant design: a preclinical study

OBJECTIVES

This study assessed bone height between novel tapered implants at different inter-implant thread peak (TP) distances, and the impact of TP distance from outer buccal bone (BB) on marginal bone levels (MBL).

MATERIALS AND METHODS

Fully tapered implants with 0.5-mm thread depth and TP diameter 1 mm wider than the shoulder diameter were placed in healed ridges of minipigs. On one side, four implants were placed with inter-implant TP distances of 1, 2, or 3 mm corresponding to inter-implant implant shoulder distances of 2, 3, and 4 mm respectively. Three implants were placed on the other side with TP distances to outer BB of > 1 mm, 0.5-1 mm, or < 0.5 mm. After 12 weeks, (a) first bone-to-implant contact (fBIC), total BIC, bone area-to-total area (BATA), and coronal bone height between implants (Bi ½ max) for inter-implant distance, and (b) fBIC, BIC, and perpendicular crest to implant shoulder (pCIS) for BB were evaluated.

RESULTS

No significant differences in bone healing and inter-implant bone height were noted for any of the TP distances. BB resorption was significant when TP distance to outer BB was < 0.5 mm. However, fBIC was lowest with TP to outer BB of 1.75 mm.

CONCLUSIONS

Inter-implant bone height between adjacent implants can be maintained even at an inter-implant TP distance as low as 1 mm. A minimum TP to outer BB distance of 0.75 mm is required for predictable maintenance of MBL.

CLINICAL RELEVANCE

Inter-implant distance and BB thickness are clinically relevant and require preclinical research to clarify concepts.

New classification for bone type at dental implant sites: a dental computed tomography study

OBJECTIVE

This study proposed a new classification method of bone quantity and quality at the dental implant site using cone-beam computed tomography (CBCT) image analysis, classifying cortical and cancellous bones separately and using CBCT for quantitative analysis.

METHODS

Preoperative CBCT images were obtained from 128 implant patients (315 sites). First, measure the crestal cortical bone thickness (in mm) and the cancellous bone density [in grayscale values (GV) and bone mineral density (g/cm³)] at the implant sites. The new classification for bone quality at the implant site proposed in this study is a "nine-square division" bone classification system, where the cortical bone thickness is classified into A: > 1.1 mm, B:0.7-1.1 mm, and C: < 0.7 mm, and the cancellous bone density is classified into 1: > 600 GV (= 420 g/cm³), 2:300-600 GV (= 160 g/cm³-420 g/cm³), and 3: < 300 GV (= 160 g/cm³).

RESULTS

The results of the nine bone type proportions based on the new jawbone classification were as follows: A1 (8.57%,27/315), A2 (13.02%), A3 (4.13%), B1 (17.78%), B2 (20.63%), B3 (8.57%) C1 (4.44%), C2 (14.29%), and C3 (8.57%).

CONCLUSIONS

The proposed classification can complement the parts overlooked in previous bone classification methods (bone types A3 and C1).

TRIAL REGISTRATION

The retrospective registration of this study was approved by the Institutional Review Board of China Medical University Hospital, No. CMUH 108-REC2-181.

The Influence of Low-Level Laser Therapy on CBCT Radiographic and Biochemical Profiles of Type II Controlled Diabetic Patients After Dental Implant Insertion: A Randomized Case-Control Study

Background Low-level laser treatment (LLLT) was thought to increase bone quality during osseointegration when combined with dental implants. However, there is no sufficient information on its impact on dental implants in diabetics. Osteoprotegerin (OPG) has been described as a marker for bone turnover to determine implant prognosis. The current research aims to evaluate the effect of low-level laser therapy (LLLT) on bone density (BD) and osteoprotegerin levels in peri-implant crevicular fluid (PICF) in type II diabetic patients. Methods This study comprised 40 individuals with type II diabetes mellitus (T2DM). Implants were randomly placed in 20 non-lasered T2DM patients (control) and 20 lasered T2DM patients (LLLT group). At the follow-up stages, BD and OPG levels in the PICF were evaluated in both groups. Results Significant variations were shown among control and LLLT groups concerning OPG level and BD (p≤0.001). OPG was significantly decreasing with follow-up points (p≤0.001). There was a significant decrease in OPG with time in both groups with a higher decrease in the control group. Conclusion LLLT is promising in controlled T2DM patients due to its outstanding influence on BD and estimated crevicular levels of OPG. Regarding its clinical significance, LLLT significantly improved bone quality during osseointegration on dental implants in T2DM. LLLT is considered potentially important for T2DM patients during implant placement. Trial registration The study was registered on ClinicalTrial.gov under registration number NCT05279911 (registration date: March 15, 2022) (https://clinicaltrials.gov/ct2/show/NCT05279911).

Short-term and long-term success and survival rates of implants supporting single-unit and multiunit fixed prostheses: A systematic review and meta-analysis

STATEMENT OF PROBLEM

Whether placing implants to replace each missing tooth or using implant-supported fixed partial dentures provides better outcomes is unclear.

PURPOSE

The purpose of this systematic review and meta-analysis was to assess the success and survival rates of implants supporting single-unit and multiunit fixed prostheses by using conventional protocols for placement and loading in short- and long-term follow-ups.

MATERIAL AND METHODS

An electronic search was conducted in PubMed, Scopus, and Web of Science for studies published up to March 17, 2022. Comparative studies that reported the success or survival rates of both single-unit and splinted multiunit prostheses were considered for qualitative and quantitative analyses.

RESULTS

A total of 68 publications comprising 11 271 implants were included. Compared with the single prostheses, the splinted multiunit group showed no significant differences in implant success rates in the short-term (risk difference=-0.004; 95% confidence interval (CI)=-0.033 to 0.025; P=.780) and long-term (risk difference=0.003; 95% confidence interval (CI)=-0.029 to 0.034; P=.874) follow-ups. Significant statistical differences were also not found in terms of the survival rates of the 2 groups (short-term risk difference=-0.004; 95% CI=-0.031 to 0.023; P=.779, long-term risk difference=-0.002; 95% CI=-0.029 to 0.025; P=.887).

CONCLUSIONS

Implants supporting single-unit or splinted multiunit prostheses seem to be a predictable treatment in terms of survival and success over short and long periods. Nonetheless, it seems that cantilever and nonsplinted multiunit prostheses should be used with more caution.

A Fixed Reconstruction and Immediate Rehabilitation of Fully Edentulous Arch Using the All-on-Four Concept: Case Series

The implant survival largely depends on the mechanical setting in which they work as an independent entity. The implant design, number and position markedly affect the treatment plan. Deficient bone quantity and quality and presence of a vital anatomical landmark have often led the practitioners to conduct researches to find newer ways of implant insertion. One such technique is the 'All-On-4' concept, an alternative to the conventional implant therapy; lessens the amount of strain to the alveolar bone by increasing the antero-posterior spread with distal tilting the posterior implant. It is a cost-effective procedure that decreases the treatment time and the morbidity rate allowing a higher patient quality of life. The article demonstrates clinical cases describing rehabilitation of completely edentulous arches using the All-On-4 concept.

Comparison of heat production and bone architecture changes in the implant site preparation with compressive osteotomes, osseodensification technique, piezoelectric devices, and standard drills: an ex vivo study on porcine ribs

This study aimed at investigating differences in heat generation and bone architecture following four different implant site preparation techniques: compressive osteotomes, conventional drills, osseodensification (OD mode with osseodensification drills), and piezoelectric systems. Porcine rib bones were used as a model for implant surgery. Thermocouples were employed to measure temperature changes, and micro-CT to assess the bone architecture. The primary stability and insertion torque values of the implants placed in the differently prepared sites were assessed. The temperature changes were higher with Piezo. The average primary stability using the ISQ scale was the greatest for drills (76.17 ± 0.90) and the lowest for osteotomes (71.50 ± 11.09). Insertion torque was significantly higher with the osseodensification method (71.67 ± 7.99 Ncm) in comparison to drills, osteotomes, and piezo. Osteotomes showed the highest bone to implant contact percentage (39.83 ± 3.14%) and average trabecular number (2.02 ± 0.21 per mm), while drills exhibited the lowest (30.73 ± 1.65%; 1.37 ± 0.34 per mm). Total implant site bone volume was the highest with osseodensification (37.26 ± 4.13mm³) and the lowest for osteotomes (33.84 ± 3.84mm³). Statistical analysis showed a high primary stability and decrease in temperature during implant site preparation with osseodensification technique. The results support the use of osseodensification technique for implant site preparation.

The effect of different methods of cleansing temporary cement (with and without eugenol) on the final bond strength of implant-supported zirconia copings after final cementation: An in vitro study

Background

The temporary cement remaining inside the dental prosthesis can act as a source of microbial colonization and contamination and decrease the final cement retention. Consequently, complete removal of temporary cement before permanent cementation is suggested. This study aimed to assess the effect of different cleaning methods for removing temporary cement on the tensile bond force (TBF) of permanently cemented implant-supported zirconia copings.

Materials and Methods

In this in vitro study fifty titanium abutments were screwed onto 50 analogs with 30 Ncm torque into in acrylic resin blocks. Each abutment was scanned separately, and 50 zirconia copings were designed and milled. Permanent resin cement was used to cement copings of control group (N = 10). Copings were divided into two temporary cementation types that in each group, two cleansing methods were used: Temp-S (temporary cement with eugenol and sandblasted after debonding), Samples of the control group were placed in the universal testing machine, and the TBF values were recorded. Samples of the test groups after debonding and cleaning the abutments were subjected to cement with permanent resin cement, aging, and removing. Levene test, two-way analysis of variance (ANOVA), and Tamhane post hoc tests were applied. α = 0.05.

Results

The highest and lowest TBF values were found for the TempNE-SU (554.7 ± 31.5 N) and Temp-S (492.2 ± 48 N) groups, respectively. The two groups of isopropyl alcohol baths in ultrasonics in combination with sandblasting showed statistically higher TBF values than the other two groups that used only sandblasting (P < 0.001) and had similar values compared to the control group.

Conclusion

Sandblasting combined with immersion in an ultrasonic bath containing isopropyl alcohol resulted in statistically similar values to the values of cementation with resin cement from the beginning. However, cleaning the inside of the copings only by sandblasting method reduced the values of the final retention force in comparison to cement with permanent resin cement from the beginning.

Metals Biotribology and Oral Microbiota Biocorrosion Mechanisms

During the last decades, metal-based biomaterials have been extensively explored to be used as biocompatible metals for biomedical applications, owing to their superior mechanical properties and corrosion resistance. Consequently, for long-term implanted medical devices, to assure the biomaterials' reliability, functionality, and biocompatibility, studying the various bio-tribological damage mechanisms to obtain the optimum properties is one of the most important goals. In this review, we consider the most important metal-based biomaterials such as stainless steel, alloys of titanium (Ti), cobalt-chromium (Co-Cr), and Nichel-Titatium (Ni-Ti), as well Magnesium (Mg) alloys and with Tantalum (Ta), emphasizing their characteristics, clinical applications, and deterioration over time. The influence of metal elements on biological safety, including significant effects of metal-based biomaterials in dentistry were discussed, considering the perspectives of surface, mechanical properties, corrosion behaviors, including interactions, bio-mechanisms with tissues, and oral environments. In addition, the role of the oral microbiota was explored due to its role in this erosion condition, in order to further understand the mechanism of metal-based biomaterials implanted on the microflora balance of aerobic and anaerobic bacteria in an oral environment.

Evaluation of health screening data for factors associated with peri-implant bone loss

PURPOSE

Systemic health has a profound effect on dental treatment. The aim of this study was to evaluate peri-implant bone loss and health screening data to discover factors that may influence peri-implant diseases.

METHODS

This study analyzed the panoramic X-rays of patients undergoing health screenings at the Health Promotion Center at Seoul St. Mary's Hospital in 2018, to investigate the relationship between laboratory test results and dental data. The patients' physical data, such as height, weight, blood pressure, hematological and urine analysis data, smoking habits, number of remaining teeth, alveolar bone level, number of implants, and degree of bone loss around the implant, were analyzed for correlations. Their associations with glycated hemoglobin, glucose, blood urea nitrogen (BUN), creatinine, and severity of periodontitis were evaluated using univariate and multivariate regression analysis.

RESULTS

In total, 2,264 patients opted in for dental health examinations, of whom 752 (33.2%) had undergone dental implant treatment. These 752 patients had a total of 2,658 implants, and 129 (17.1%) had 1 or more implants with peri-implant bone loss of 2 mm or more. The number of these implants was 204 (7%). Body mass index and smoking were not correlated with peri-implant bone loss. Stepwise multivariate regression analysis revealed that the severity of periodontal bone loss (moderate bone loss: odds ratio [OR], 3.154; 95% confidence interval [CI], 1.175-8.475 and severe bone loss: OR, 7.751; 95% CI, 3.003-20) and BUN (OR, 1.082; 95% CI, 1.027-1.141) showed statistically significant predictive value. The severity of periodontitis showed greater predictive value than the biochemical parameters of blood glucose, renal function, and liver function.

CONCLUSIONS

The results of this study showed that periodontal bone loss was a predictor of peri-implant bone loss, suggesting that periodontal disease should be controlled before dental treatment. Diligent maintenance care is recommended for patients with moderate to severe periodontal bone loss.

Prevalence of dental implant positioning errors: A cross-sectional study

Purpose

This study evaluated the prevalence of dental implant positioning errors and the most frequently affected oral regions.

Materials and Methods

A sample was obtained of CBCT images of 590 dental implants from 230 individuals who underwent diagnosis at a radiology center using cone-beam computed tomography from 2017 to 2020. The following variables were considered: thread exposure, violation of the minimum distance between 2 adjacent implants and between the implant and tooth, and implant contact with anatomical structures. Descriptive data analysis and the Pearson chi-square test (P<0.05) were performed to compare findings according to mouth regions.

Results

Most (74.4%) of the 590 implants were poorly positioned, with the posterior region of the maxilla being the region most frequently affected by errors. Among the variables analyzed, the most prevalent was thread exposure (54.7%), followed by implant contact with anatomical structures, violation of the recommended distance between 2 implants and violation of the recommended distance between the implant and teeth. Thread exposure was significantly associated with the anterior region of the mandible (P<0.05). The anterior region of the maxilla was associated with violation of the recommended tooth-implant distance (P<0.05) and the recommended distance between 2 adjacent implants (P<0.05). Implant contact with anatomical structures was significantly more likely to occur in the posterior region of the maxilla (P<0.05).

Conclusion

Many implants were poorly positioned in the posterior region of the maxilla. Thread exposure was particularly frequent and was significantly associated with the anterior region of the mandible.

Evaluation of oral implant survival rate in postmenopausal women with osteopenia/osteoporosis. A retrospective pilot study

BACKGROUND

Implant placement is a common part of dental rehabilitation in older individuals. The role of diminished bone mineral density on the healing of dental implants remains to be elucidated.

OBJECTIVE

The aim of this study was to assess the implant survival rate in postmenopausal women with osteopenia/osteoporosis.

METHODS

A retrospective cohort study was conducted of postmenopausal women treated with dental implants and stratified into two groups: those receiving antiresorptive therapy (W ≥ 50 years S) or those not receiving treatment (W ≥ 50 years U). The predictor variable was osteopenia/osteoporosis treatment. The outcome variable was implant failure rate at stage two uncovering. Other study variables included: age, implant location, and bone graft placement. T-test, chi-square test, and univariate and multivariate logistic regression were computed. A p-value<0.05 was considered statistically significant.

RESULTS

The sample was composed of 93 W ≥ 50 years U (197 implants) and 114 W ≥ 50 years S (189 implants). W ≥ 50 years U showed a statistically higher implant failure rate with chi-square testing compared to W ≥ 50 years S (p=0.022). However, univariate, and multivariate logistic regression between age, location, bone grafting, and implant failure did not demonstrate significant associations.

CONCLUSION

Both groups integrated dental implants successfully, with a low failure rate. Implant location, bone grafting, and osteopenia/osteoporosis treatment did not significantly affect osseointegration at uncovering.

Long-Term Survival Rate of Autogenous Tooth Transplantation: Up to 162 Months

Background and Objectives: The purpose of this study is to observe the usefulness of autogenous tooth transplantation by examining the cumulative survival rate according to the period of auto-transplanted teeth as pre-implant treatment. Materials and Methods: This study was conducted on 111 patients who visited Kyungpook National University Dental Hospital and underwent autogenous tooth transplantation between November 2008 and January 2021 (about 13 years). The cumulative survival rate of autogenous tooth transplantation according to the causes of extraction of the recipient tooth (caries, periapical lesion, crack, crown fracture, periodontitis) and condition of opposing teeth (natural teeth vs. fixed prosthesis). The cumulative survival rate of autogenous tooth transplantation according to the age (under 30 vs. over 30) was also investigated and it was examined whether there were any differences in each factor. Results: The average follow-up period was 12 months, followed by a maximum of 162 months. The 24-month cumulative survival rate of all auto-transplanted teeth was 91.7%, 83.1% at 60 months and the 162-month cumulative survival rate was 30.1%. There were no statistical differences between the causes of extraction of the recipient's teeth, differences in the condition of the opposing teeth, and differences under and over the age of 30. Conclusions: The survival rate of autogenous tooth transplantation appears to be influenced by the conditions of the donor tooth rather than the conditions of the recipient tooth. Although autogenous tooth transplantation cannot completely replace implant treatment, it is meaningful in that it can slightly delay or at least earn the time until implant placement is possible.

Design of patient specific basal dental implant using Finite Element method and Artificial Neural Network technique

The bone conditions of mandibular bone vary from patient to patient, and as a result, a patient-specific dental implant needs to be designed. The basal dental implant is implanted in the cortical region of the bone since the top surface of the bone narrows down because of aging. Taguchi designs of experiments technique are used in which 25 optimum solid models of basal dental implants are modeled with variable geometrical parameters, viz. thread length, diameter, and pitch. In the solid models the implants are placed in the cortical part of the 3D models of cadaveric mandibles, that are prepared from CT data using image processing software. Patient-specific bone conditions are varied according to the strong, weak, and normal basal bone. A compressive force of 200 N is applied on the top surface of these implants and using finite element analysis software, the microstrain on the peri-implant bone ranges from 1000 to 4000 depending on the various bone conditions. According to the finite element data, it can be concluded that weak bone microstrain is comparatively high compared with normal and strong bone conditions. A surrogate artificial neural network model is prepared from the finite element analysis data. Surrogate model assisted genetic algorithm is used to find the optimum patient-specific basal dental implant for a better osseointegration-friendly mechanical environment.

Marginal bone loss around crestal or subcrestal dental implants: prospective clinical study

Objectives

The stability of crestal bone has been reported as a major factor in the success of dental implants. Implants can be placed in an equicrestal (crestal) or subcrestal position. The aim of this study was to evaluate the effect of implant depth placement on marginal bone loss.

Materials and Methods

The study was created in a split-mouth design. Immediately after implant surgery, digital parallel radiographs were prepared and levels of bone were measured where marginal bone loss and bone level changes occurred. These measurements were repeated at 3-month and 6-month follow-up periods.

Results

In this interventional study, 49 implants were evaluated in 18 patients. Primary bone height was not significant between the intervention and control groups in both mesial and distal aspects at 3 months and 6 months from the baseline. The mean marginal bone loss on the mesial side was 1.03 mm in the subcrestal group and 0.83 mm in the crestal group. In addition, mean marginal bone loss on the distal side was 0.88 mm and 0.81 mm in the subcrestal and crestal groups, respectively. Marginal bone loss was not significantly different between sexes, the maxilla or mandible, and in the anterior or posterior regions as well as between different lengths and diameters of implants.

Conclusion

Based on the results of this study, there was no significant difference in terms of marginal bone loss between crestal and subcrestal implants.

Effects of Two Protocols of Low-Level Laser Therapy on the Proliferation and Differentiation of Human Dental Pulp Stem Cells on Sandblasted Titanium Discs: An In Vitro Study

Introduction: Stem cell activities have different effects on tissue response and its outcomes. Low-level laser therapy (LLLT) can be considered a trigger to modify stem cell activities. The objective of the present experimental investigation was to study the effects of two protocols of LLLT on the proliferation and differentiation of human dental pulp stem cells (hDPSCs) cultured on sandblasted titanium discs. Methods: Cells obtained from human dental pulp were seeded/cultured on titanium discs and were set in 2 main groups: (i) Radiated cells using the gallium-aluminium-arsenide (GaAlAs) diode laser at a continuous wavelength of 808 nm at 3 J/cm² for 12 sec or 5 J/cm² for 20 seconds, and (ii) Non-irradiated cells serving as control groups. The impact of LLLTs on hDPSC-proliferation and viability was investigated using the MTT assay after 24, 72 and 96 hours. The alkaline phosphatase activity was studied with p-nitrophenylphosphate after 14 and 28 days. The ability of hDPSCs to express osteocalcin was investigated using real-time polymerase chain reaction after 28 days, while their attachment was observed under a scanning electron microscope (SEM) after 14 and 28 days. Results: Our study showed that LLLTs caused maximum cell proliferation in 96 hours (P<0.001) with 3 J/cm² resulting in a higher proliferation rate. The highest activity of alkaline phosphatase and osteocalcin expression was observed in the laser radiation groups after 28 days. Conclusion: The outcomes of the current study showed that cultured hDPSCs on sandblasted titanium discs had a tendency towards increased cellular activity in response to LLLTs. Thus, LLLTs could regulate the activities of hDPSCs on bone repair surrounding the sandblasted titanium discs.

Probing combinational influence of design variables on bone biomechanical response around dental implant-supported fixed prosthesis

This study aimed to understand the effect of physiological and dental implant-related parameter variations on the osseointegration for an implant-supported fixed prosthesis. Eight design factors were considered (implant shape, diameter, and length; thread pitch, depth, and profile; cantilever [CL] length and implant-loading protocol). Total 36 implantation scenarios were simulated using finite element method based on Taguchi L₃₆ orthogonal array. Three patient-specific bone conditions were also simulated by scaling the density and Young's modulus of a mandible sample to mimic weak, normal, and strong bones. Taguchi method was employed to determine the significance of each design factor in controlling the peri-implant cortical bone microstrain. For normal bone condition, CL length had the maximum contribution (28%) followed by implant diameter (18%), thread pitch (14%), implant length (8%), and thread profile (5%). For strong bone condition, CL and implant diameter had equal contribution (32%) followed by thread pitch (7%) and implant length (5%). For weak bone condition, implant diameter had the highest contribution (31%) followed by CL length (30%), thread pitch (11%) and implant length (8%). The presence of distal CL in dental framework was found to be the most influential design factor, which can cause high strain in the cervical cortical bone. It was seen that implant diameter had more effect compared to implant length toward peri-implant bone biomechanical response. Implant-loading time had no significant effect towards peri-implant bone biomechanical response, signifying immediate loading is possible with sufficient mechanical retention.

Evaluating systemic administration effect of propranolol on osseointegration around titanium implants: A histomorphometric study in dogs

Background

Dental implants are known as a widely accepted and predictable method to replace missing teeth. Many factors, including using a class of drugs, such as β-blockers, can improve the osseointegration of dental implants. This study aimed to investigate the relationship between administrating propranolol and osseointegration in dental implants.

Materials and Methods

This experimental animal study was performed on four native male street dogs of 11-13 kg of weight and 16-20 months of age. The specimens underwent teeth extraction. After that, the dogs were randomly divided into two groups. The first group contains two control dogs which would receive oral saline. The second contains two dogs which would receive oral tablets of propranolol daily. After a period of healing, three titanium implants were inserted in each of speciments' left mandibular quadrant, and treatment was resumed with propranolol and saline administration in case and control group, respectively. After 4 weeks, one of control group dogs and one of case group were anesthetized, and dental implants were removed alongside the peripheral bone marrow using a trephine drill. Meanwhile, the other two dogs (1 control and 1 propranolol administered dogs) were anesthetized after 9 weeks of implant placement, and the same procedure was carried out.

Results

Due to the histomorphometric assessment, the mean score of bone implant contact (BIC) in week 4 was significantly higher in case group compared to control one (68.33% vs. 20.22%). In week 9, the mean BIC score was higher in case group compared to control group (68.60% vs. 50.17%); meanwhile, in contrast to week 4, it was not statistically significant. In both case and control groups, the formation of woven and lamellar bone was more significant in week 4 rather than week 9.

Conclusion

Administration of systemic β-blockers can improve dental implants osseointegration process.

Augmented Reality and Virtual Reality in Dentistry: Highlights from the Current Research

Many modern advancements have taken place in dentistry that have exponentially impacted the progress and practice of dentistry. Augmented reality (AR) and virtual reality (VR) are becoming the trend in the practice of modern dentistry because of their impact on changing the patient’s experience. The use of AR and VR has been beneficial in different fields of science, but their use in dentistry is yet to be thoroughly explored, and conventional ways of dentistry are still practiced at large. Over the past few years, dental treatment has been significantly reshaped by technological advancements. In dentistry, the use of AR and VR systems has not become widespread, but their different uses should be explored. Therefore, the aim of this review was to provide an update on the contemporary knowledge, to report on the ongoing progress of AR and VR in various fields of dental medicine and education, and to identify the further research required to achieve their translation into clinical practice. A literature search was performed in PubMed, Scopus, Web of Science, and Google Scholar for articles in peer-reviewed English-language journals published in the last 10 years up to 31 March 2021, with the help of specific keywords related to AR and VR in various dental fields. Of the total of 101 articles found in the literature search, 68 abstracts were considered suitable and further evaluated, and consequently, 33 full-texts were identified. Finally, a total of 13 full-texts were excluded from further analysis, resulting in 20 articles for final inclusion. The overall number of studies included in this review was low; thus, at this point in time, scientifically-proven recommendations could not be stated. AR and VR have been found to be beneficial tools for clinical practice and for enhancing the learning experiences of students during their pre-clinical education and training sessions. Clinicians can use VR technology to show their patients the expected outcomes before the undergo dental procedures. Additionally, AR and VR can be implemented to overcome dental phobia, which is commonly experienced by pediatric patients. Future studies should focus on forming technological standards with high-quality data and developing scientifically-proven AR/VR gadgets for dental practice.

Effects of Dicationic Imidazolium-Based Ionic Liquid Coatings on Oral Osseointegration of Titanium Implants: A Biocompatibility Study in Multiple Rat Demographics

Dicationic imidazolium-based ionic liquids with amino acid anions, such as IonL-phenylalanine (IonL-Phe), have been proposed as a multifunctional coating for titanium (Ti) dental implants. However, there has been no evaluation of the biocompatibility of these Ti coatings in the oral environment. This study aims to evaluate the effects of IonL-Phe on early healing and osseointegration of Ti in multiple rat demographics. IonL-Phe-coated and uncoated Ti screws were implanted into four demographic groups of rats to represent biological variations that could affect healing: young males (YMs) and females (YFs), ovariectomized (OVXFs) females, and old males (OMs). Samples underwent histopathological and histomorphometric analysis to evaluate healing at 7 and 30 days around IonL-coated and uncoated Ti. The real-time quantitative polymerase chain reaction was also conducted at the 2- and 7-day YM groups to evaluate molecular dynamics of healing while the IonL-Phe was present on the surface. IonL-coated and uncoated implants demonstrated similar histological signs of healing, while coated samples’ differential gene expression of immunological and bone markers was compared with uncoated implants at 2 and 7 days in YMs. While YMs presented suitable osseointegration for both uncoated and IonL-Phe-coated groups, decreased success rate in other demographics resulted from lack of supporting bone in YFs and poor bone quality in OVXFs and OMs. Overall, it was found that IonL-coated samples had increased bone-to-implant contact across all demographic groups. IonL-Phe coating led to successful osseointegration across all animal demographics and presented the potential to prevent failures in scenarios known to be challenged by bacteria.

Free-Hand versus Surgical Guide Implant Placement

One of the most key areas of dentistry is dental implant surgery. The use of digital equipment and software in dentistry has developed considerably in recent years compared to other fields of medicine. Since examining the advantages and disadvantages of each approach, along with case studies, can help physicians make informed decisions, this review study aims to raise the awareness of dentists to make easier decisions about using guided or free-hand surgery. When planning for a dental implant, one of the most challenging questions that doctors face is which method to use (guided surgery or free-hand). Choosing the right method, such as other clinical considerations, will depend on the individual circumstances of each patient and the preference of the treating physician. Free-hand surgery is a cost-effective method in which the flap is reflected, and, according to the doctor's diagnostic information, an implant is placed, which in many cases is a useful method. Guided surgery has the highest level of accuracy and control, in which osteotomy is designed and printed through a digital surgery guide, and depending on the complexity of the case and the patient's anatomy, it has a higher level of value than free surgery. The surgical guide helps the surgeon make the implant surgery more accurate, safer, simpler, at a lower cost, and in less time. In fact, there are patterns that convey information about the position of the tooth to the dentist before the implant is placed.