Physiopathology of peri-implant diseases

Peri-implantitis with a potential axis to brain inflammation: an inferential review

Peri-implantitis (PI) is a chronic, inflammatory, and infectious disease which affects dental implants and has certain similarities to periodontitis (PD). Evidence has shown that PD may be related to several types of systemic disorders, such as diabetes and insulin resistance, cardiovascular diseases, respiratory tract infections, adverse pregnancy outcomes, and neurological disorders. Furthermore, some types of bacteria in PD can also be found in PI, leading to certain similarities in the immunoinflammatory responses in the host. This review aims to discuss the possible connection between PI and neuroinflammation, using information based on studies about periodontal disorders, a topic whose connection with systemic alterations has been gaining the interest of the scientific community. Literature concerning PI, PD, and systemic disorders, such as neuroinflammation, brain inflammation, and neurological disorder, was searched in the PubMed database using different keyword combinations. All studies found were included in this narrative review. No filters were used. Eligible studies were analyzed and reviewed carefully. This study found similarities between PI and PD development, maintenance, and in the bacterial agents located around the teeth (periodontitis) or dental implants (peri-implantitis). Through the cardiovascular system, these pathologies may also affect blood-brain barrier permeability. Furthermore, scientific evidence has suggested that microorganisms from PI (as in PD) can be recognized by trigeminal fiber endings and start inflammatory responses into the trigeminal ganglion. In addition, bacteria can traverse from the mouth to the brain through the lymphatic system. Consequently, the immune system increases inflammatory mediators in the brain, affecting the homeostasis of the nervous tissue and vice-versa. Based on the interrelation of microbiological, inflammatory, and immunological findings between PD and PI, it is possible to infer that immunoinflammatory changes observed in PD can imply systemic changes in PI. This, as discussed, could lead to the development or intensification of neuroinflammatory changes, contributing to neurodegenerative diseases.

PRF Lysates Modulate Chemokine Expression in Oral Squamous Carcinoma and Healthy Epithelial Cells

Platelet-rich fibrin (PRF), originally used to support soft tissue healing, is also considered a therapeutic option for treating oral lichen planus and leukoplakia. The progression from the two premalignant lesions to the aggressive malignant oral squamous cell carcinoma involves an inflammatory process linked to chemokine expression. Thus, there is a rationale for studying how PRF modulates the expression of chemokines in oral squamous carcinoma cells. To this aim, we expose the oral squamous carcinoma cell line HSC2 to IL1β and TNFα either alone or in the presence of lysates obtained from solid PRF membranes. We report here that in HSC2 cells, PRF lysates significantly reduce the forced transcription of chemokines, e.g., CXCL1, CXCL2, CXCL8, CXCL10, and CCL5. Moreover, PRF lysates attenuate the nuclear translocation of p65 in HSC2 oral epithelial cells when exposed to IL1β and TNFα. PRF lysates further reduce chemokine expression provoked by poly:IC HMW. Even though less pronounced, PRF lysates reduce IL1β- and TNFα-induced chemokine expression in TR146 cells. In primary oral epithelial cells, however, PRF lysates increase the basal expression of CXCL1, CXCL2 and CXCL8. Thus, PRF can exert a biphasic effect on chemokine expression in oral squamous cell carcinoma cell lines and primary oral epithelial cells. These findings suggest that PRF may reduce inflammation in a malignant environment while provoking an immunological response in healthy oral epithelium.

Experimental models for peri-implant diseases: a narrative review

OBJECTIVES

Peri-implant diseases, being the most common implant-related complications, significantly impact the normal functioning and longevity of implants. Experimental models play a crucial role in discovering potential therapeutic approaches and elucidating the mechanisms of disease progression in peri-implant diseases. This narrative review comprehensively examines animal models and common modeling methods employed in peri-implant disease research and innovatively summarizes the in vitro models of peri-implant diseases.

MATERIALS AND METHODS

Articles published between 2015 and 2023 were retrieved from PubMed/Medline, Web of Science, and Embase. All studies focusing on experimental models of peri-implant diseases were included and carefully evaluated.

RESULTS

Various experimental models of peri-implantitis have different applications and advantages. The dog model is currently the most widely utilized animal model in peri-implant disease research, while rodent models have unique advantages in gene knockout and systemic disease induction. In vitro models of peri-implant diseases are also continuously evolving to meet different experimental purposes.

CONCLUSIONS

The utilization of experimental models helps simplify experiments, save time and resources, and promote advances in peri-implant disease research. Animal models have been proven valuable in the early stages of drug development, while technological advancements have brought about more predictive and relevant in vitro models.

CLINICAL RELEVANCE

This review provides clear and comprehensive model selection strategies for researchers in the field of peri-implant diseases, thereby enhancing understanding of disease pathogenesis and providing possibilities for developing new treatment strategies.

The Integration of Advanced Drug Delivery Systems into Conventional Adjuvant Therapies for Peri-Implantitis Treatment

Despite the high success rates of dental implants, peri-implantitis is currently the most common complication in dental implantology. Peri-implantitis has an inflammatory nature, it is associated with the accumulation of plaque in the peri-implant tissues, and its evolution can be progressive depending on various factors, comorbidities, and poor oral health. Prophylaxis and different treatment methods have been widely discussed in recent decades, and surgical and non-surgical techniques present both advantages and disadvantages. In this work, a literature review of different studies on the application of adjuvant treatments, such as local and systemic antibiotics and antiseptic treatments, was conducted. Positive outcomes have been found in the short (up to one year after treatment) and long term (up to ten years after treatment) with combined therapies. However, there is still a need to explore new therapies based on the use of advanced drug delivery systems for the effective treatment of peri-implantitis in the long term and without relapses. Hence, micro- and nanoparticles, implants, and injectable hydrogels, among others, should be considered in future peri-implantitis treatment with the aim of enhancing overall therapy outcomes.

Influence of keratinized mucosa width on the resolution of peri-implant mucositis: A prospective cohort study

BACKGROUND

The prevalence of peri-implant diseases, driven by biofilm accumulation and influenced by factors such as the width of keratinized mucosa (KM), underscores the need for understanding their etiology and management.

PURPOSE

To evaluate the association between the KM width and the clinical resolution of peri-implant mucositis after mechanical therapy.

MATERIALS AND METHODS

Patients with an implant diagnosed with peri-implant mucositis were allocated to two groups: wide band of KM (WKM ≥ 2 mm) and narrow/no band of KM (NKM < 2 mm). Data and submucosa biofilm were collected at baseline and at 8, 12, and 24 weeks after nonsurgical therapy. A Brunner-Langer model was estimated for longitudinal data to evaluate and compare changes in any clinical parameter throughout follow-up between both groups. Furthermore, the microbial profiles were evaluated by 16S rRNA gene sequencing.

RESULTS

A total of 38 implants were analyzed. At 24 weeks, bleeding on probing was substantially reduced in both groups, reaching statistical significance (p < 0.001). Treatment resulted in 23.9% less effective in achieving success for NKM. As such, NKM reduced the odds of disease resolution by 80% compared to WKM. The rest of the explored clinical parameters yielded more favorable outcomes for WKM versus NKM. Neither the alpha nor the beta diversity of the microbial profiles were significantly modulated by KM.

CONCLUSIONS

KM width influences the clinical resolution of peri-implant mucositis after mechanical therapy (https://clinicaltrials.gov/study/NCT04874467?cond=keratinized%20mucosa&rank=8, NCT04874467, 04/30/2021).

Surgical treatment of peri-implantitis

As utilisation of dental implants continues to rise, so does the incidence of biological complications. When peri-implantitis has already caused extensive bone resorption, the dentist faces the dilemma of which therapy is the most appropriate to maintain the implant. Since non-surgical approaches of peri-implantitis have shown limited effectiveness, the present paper describes different surgical treatment modalities, underlining their indications and limitations. The primary goal in the management of peri-implantitis is to decontaminate the surface of the infected implant and to eliminate deep peri-implant pockets. For this purpose, access flap debridement, with or without resective procedures, has shown to be effective in a large number of cases. These surgical treatments, however, may be linked to post-operative recession of the mucosal margin. In addition to disease resolution, reconstructive approaches also seek to regenerate the bone defect and to achieve re-osseointegration.

Do Concurrent Peri-Implantitis and Periodontitis Share Their Microbiotas? A Pilot Study

The microbial compositions from concurrent peri-implant and periodontal lesions were compared, since the results reported in the literature on the etiological relationship between these oral pathologies are contradictory. Microbial compositions from nine patients were evaluated using Illumina MiSeq sequencing of 16S rRNA gene amplicons and Principal Components Analysis. Comparisons between the use of curettes or paper points as collection methods and between bacterial composition in both pathologies were performed. Paper points allowed the recovery of a higher number of bacterial genera. A higher bacterial diversity was found in peri-implantitis compared to periodontal samples from the same patient, while a greater number of operational taxonomic units (OTUs) were present in the corresponding periodontal samples. A higher abundance of oral pathogens, such as Porphyromonas or Treponema, was found in peri-implantitis sites. The opposite trend was observed for Aggregatibacter abundance, which was higher in periodontal than in peri-implantitis lesions, suggesting that both oral pathologies could be considered different but related diseases. Although the analysis of a higher number of samples would be needed, the differences regarding the microbial composition provide a basis for further understating the pathogenesis of peri-implant infections.

A Single Dose of Piperacillin Plus Tazobactam Gel as an Adjunct to Professional Mechanical Plaque Removal (PMPR) in Patients with Peri-Implant Mucositis: A 6-Month Double-Blind Randomized Clinical Trial

OBJECTIVES

This randomized, placebo-controlled, double-masked clinical trial aimed to evaluate the clinical and microbiological efficacy of professional mechanical plaque removal (PMPR) with or without adjunctive application of piperacillin plus tazobactam gel in the treatment of peri-implant mucositis (PiM) for up to 6 months.

MATERIALS AND METHODS

The study included 31 patients with peri-implant mucositis (bleeding on probing (BoP) > 1 at at least one site at baseline, absence of peri-implant bone loss compared with a previous radiograph). After randomized assignment to test and control groups, patients received full-mouth supragingival scaling with or without piperacillin plus tazobactam gel. Clinical examination was performed at baseline and after 3 and 6 months, and a microbiological examination was performed at baseline and after 3 months.

RESULTS

After six months, both treatment modalities resulted in significant reductions and improvements in clinical parameters at the implant sites. Neither study group achieved a complete resolution of PiM (i.e., BoP ≤ 1 per implant). The number of implants with BoP decreased statistically significantly between subsequent time points (p < 0.001) in both the test and the control group. Significant BoP differences (p = 0.039) were observed between groups at 6 months (difference to baseline) following therapy.

CONCLUSIONS

Within the limitations of the present study, the single use of a slow-release, locally applied antibiotic combination of piperacillin and tazobactam gel, adjunctive to PMPR, showed an improvement in clinical variable of implants diagnosed with PiM. The adjunctive treatment resulted in higher BoP reduction when compared to the control, but no significant differences were observed regarding the changes in other clinical and microbiological parameters.

Comprehensive treatment protocol for peri-implantitis: an up-to date narrative review of the literature

This narrative review describes up-to-date treatment options for peri-implantitis and proposes a treatment protocol and flowchart based on the current scientific evidence. Peri-implantitis treatment should be based on the phased treatment protocol for periodontitis, which is a continuous flow of decisions for extraction, nonsurgical and surgical treatments with step-by-step re-evaluation. The protocol's goals are to fulfill the success criteria for peri-implantitis treatment (probing depth of ≤5 mm, and absence of bleeding on probing, suppuration, and progressive bone loss) and to halt disease progression. Fixtures with peri-implantitis can initially be classified as failed or failing. A failed implant needs to be removed. In contrast, nonsurgical and surgical treatments can be applied to a failing implant. Nonsurgical treatment should be the initial treatment for failing implants; however, sole nonsurgical treatment was regarded as inefficient for peri-implantitis. Recent studies have found that the adjunctive use of antibiotics to nonsurgical debridement increased the success of nonsurgical treatment for peri-implantitis. Surgical treatments can be classified into resective, access, and reconstructive surgeries. The technique should be selected according to the patient's bone defect configuration, which relate to regenerative potential. Various combinations of decontamination methods (e.g., mechanical, chemical, and pharmacological approaches) are required to achieve absolute surface decontamination. Clinicians should select an appropriate surface decontamination strategy according to the purpose of surgery. After signs of disease disappear and its progression is halted through active peri-implantitis treatment, it is necessary to enroll patients into maintenance programs. Compliance of patients with the maintenance program reduces the recurrence of peri-implantitis and sustains clinical success after treatment. Maintenance visits should include professional plaque control and hygiene care reinforcement for patients, and their interval should be set according to individual peri-implantitis risk. Clinicians should remind that peri-implantitis treatment is not a single procedure, but rather a continuing cycle of treatment and re-evaluation.

Saliva biofilm-derived outer membrane vesicles regulate biofilm formation and immune response of oral epithelial cells on titanium surfaces

OBJECTIVES

While the significant roles of outer membrane vesicles (OMVs) from individual oral bacterial species in bacterial-host interactions are known, the involvement of saliva biofilm-derived OMVs in peri-implant disease pathogenesis remains unclear. This study aimed to investigate the effect of saliva biofilm-derived OMVs on regulating saliva biofilm formation and modulating the immune response of the epithelial cells on titanium surfaces.

MATERIALS AND METHODS

Saliva derived biofilms were cultured on tissue culture plates (TCP) for 4 days using pooled saliva from four healthy donors. OMVs secreted from the TCP bound biofilm (referred to as OMVs or healthy saliva biofilm OMVs) were enriched using the size-exclusion chromatography method. We then evaluated the effects of these OMVs on the viability, metabolic activity, and the presence of oral pathogens in saliva biofilm grown on titanium discs for 24 h and 72 h. Furthermore, the impact of OMVs on the mRNA expression and inflammatory cytokines [interleukin (IL)-6, IL-1α, and monocyte chemoattractant protein-1 (MCP-1)] in human oral epithelial cells (OKF6/TERT-2) was investigated using RT-qPCR and enzyme-linked immunosorbent assay (ELISA), respectively.

RESULTS

Healthy saliva biofilm OMVs improved the biomass and activity of saliva biofilm cultured on the titanium surfaces, with inhibited Porphyromonas gingivalis and Fusobacterium nucleatum, and enhanced Streptococcus mutans expression. Additionally, OMVs increased pro-inflammatory cytokine IL-6 mRNA and IL-6 cytokine expression in human oral epithelial cells. However, IL-1α and MCP-1 cytokines were inhibited 24-hour post-incubation with OMVs.

CONCLUSION

Healthy saliva biofilm derived OMVs regulate the activity and pathogen composition of biofilms formed on titanium, while modulating the secretion of pro-inflammation factors of oral epithelial cells grown on titanium surfaces.

CLINICAL RELEVANCE

Healthy saliva biofilm OMVs may regulate the early biofilm formation on abutment surfaces and modulate epithelial cell immune response, which may alter the peri-implant niche and participate in the pathogenesis of peri-implant disease.

Knowledge and attitude of dental students regarding etiology, diagnosis, and treatment of peri-implantitis

OBJECTIVE

The objective of this study was to assess the level of knowledge and attitude of dental students about the etiology, diagnosis, and management of peri-implantitis.

METHODS

An online cross-sectional study that targeted senior undergraduate dental students at the College of Dentistry was conducted. A closed-ended survey consisting of 28 questions was designed. Three sections were created: 1) participants' characteristics; 2) Knowledge of peri-implantitis etiology, risk factors, diagnosis, and complications; 3) The use of antibiotics in peri-implantitis, diagnosis, and treatment methods. SPSS version 22 (IBM Corp.) was used for data analysis. Counts and percentages were calculated for correct answers in each section.

RESULTS

A total of 267 dental students responded to the questionnaire. The majority of the participants (81.6%) were knowledgeable about peri-implantitis being an inflammatory reaction, and a lesser percentage (77.9%) knew that bacterial plaque is an etiologic factor for peri-implant diseases. 82.0% of the participants identified smoking as a risk factor, followed by periodontitis (80.5%). Regarding implant complications, 57.3% of the participants considered implant mobility as a definitive indication for implant removal. More than half of the participants reported using crater-like bone defects surrounding implants to diagnose peri-implantitis. The most commonly used antibiotic was amoxicillin (34.1%), followed by amoxicillin combined with metronidazole (26.9%).

CONCLUSION

Most participants had a basic understanding of the etiology and risk factors of peri-implantitis. On the other hand, more courses addressing peri-implantitis diagnosis are needed.

Comparative Assessment of Catalase Levels in Peri-Implant Health and Disease

Peri-implant disease pathogenesis is similar to periodontal disease pathogenesis resulting in production of pro-inflammatory mediators. These mediators alter the redox balance leading to decrease in antioxidants, among which catalase is one of the enzymatic antioxidants. The aim of the study was to compare the levels of catalase in peri-implant health and disease. The present observational study was carried out from June 2022 to December 2022 in the Department of Implantology, Saveetha Dental College and Hospitals, Chennai, India. A total of 60 patients with peri-implant health (Group 1; n = 20), peri-implant mucositis (Group 2; n = 20) and peri-implantitis (Group 3; n = 20) were enrolled. Unstimulated salivary samples were collected and subjected to ELISA for catalase analysis. Catalase levels were then compared between the groups using ANOVA. The mean catalase level in peri-implant health, peri-implant mucositis, peri-implanti-tis were 25.07 ± 0.44 U/mL, 18.5 6 ± 0.65 U/mL, and 11.25 ± 0.76 U/mL respectively. The difference between the three groups were statistically significant (P < 0.05). Catalase level decreases with severity of peri-implant diseases. Therefore, catalase can be used as a diagnostic marker for peri-implant diseases.

Influence of antiresorptive/antiangiogenic therapy on the surgical treatment outcomes of experimentally induced peri-implantitis lesions

OBJECTIVE

To investigate the influence of various antiresorptive and antiangiogenic medications on the resolution of experimentally induced peri-implantitis lesions after different surgical treatment approaches.

MATERIALS AND METHODS

Forty-eight albino rats randomly received a dual application of the following medications: (1) amino-bisphosphonate (zoledronate (Zo)) (n = 8), (2) RANKL inhibitor (denosumab (De)) (n = 8), (3) antiangiogenic (bevacizumab (Be)) (n = 8), (4) Zo + Be (n = 8), (5) De + Be (n = 8), or (6) no medication (control (Co)) (n = 8). Ligature-induced peri-implantitis lesions were established at 2 maxillary implants over 16 weeks. Afterward, animals were randomly treated either with open flap debridement (OFD) or reconstructive therapy (RT). Treatment procedures were followed by a 12-week healing period. The histological outcomes included residual defect length (DL); defect width (DW) at the bone crest (BC-DW); 25%, 50%, and 75% of the DL; and areas of inflammatory cell infiltrate (ICT). When present, areas of bone sequester (BS) were assessed considering the animal as a statistical unit.

RESULTS

A total of 21 animals were analyzed (Zo: RT = 3, OFD = 1; De: RT = 3, OFD = 2; Be: OFD = 1; Zo + Be: RT = 2, OFD = 2; Co: RT = 3, OFD = 2). Implant loss rates were comparable among the experimental groups. Except for the 25% and 75% DW values that were significantly higher in the Zo + Be group compared to the Co group (p = 0.04 and p = 0.03, respectively), no significant differences were found among the experimental groups for the DL (lowest-Be: 0.56 mm; highest-Co: 1.05 mm), BC-DW (lowest-De: 0.86 mm, highest-Co: 1.07 mm), 50% DW (lowest-De: 0.86 mm; highest-Be + Zo: 1.29 mm), and ICT (lowest-Be: 0.56 mm2; highest-Be + Zo: 1.65 mm2). All groups, except for the Zo and Be following RT, showed presence of BS.

CONCLUSIONS

The present findings did not reveal a marked effect of various antiresorptive/antiangiogenic medications on the resolution of experimentally induced peri-implantitis lesions, regardless of the surgical approach employed (OFD and RT).

CLINICAL RELEVANCE

Resolution of peri-implantitis lesions may not be affected by the investigated antiresorptive/antiangiogenic medications.

A systematic review on removal of osseointegrated implants: un update

BACKGROUND

Today dental implants represent an effective therapy in case of partial or total edentulism, with an excellent success rate. Despite the results obtained, there may be biological or mechanical complications during the therapy, which lead to the loss of the implant. This systematic review aims to evaluate the current state of the art in the literature on techniques used for the removal of dental implants. Various aspects will be analyzed, such as the success of the technique, any complications, and the advantages and disadvantages of their use.

METHODS

Two reviewers conducted a literature analysis (PubMed, Embase, Web of Science) of the last 20 years (2003-2023). The main criterion analyzed was the success of the technique, while secondary outcomes such as complications and risks of the technique were also analyzed. 258 articles were identified in the various search databases. 42 eligible articles were subsequently identified after an article screening. Only 18 full texts were subsequently included in the review.

RESULTS

A total of 18 articles were selected and 1142 implants and 595 patients were included. The main techniques used were the Counter-Torque Ratchet Technique (CTRT), Piezoelectric bone surgery (PBS), trephine drills, carbide burs, Erbium, Chromium, Yttrium, Scandium, Gallium, Garnett (Er:Cr:YSGG) laser and carbon dioxide (CO2) laser. Combined uses of techniques have been identified such as: PBS and trephine burs or carbide burs, trephine burs with the use of a 3d-printed guide, CTRT and trephine burs. The technique with the highest success rate, less morbidity for the patient, and less removal of bone appears to be the CTRT.

CONCLUSIONS

The use of conservative techniques, especially CTRT, in bone removal is useful to allow for immediate implant placement in the removal area. However, further studies with a high sample size are needed to be performed on all techniques, particularly new randomized controlled trials (RCTs) that allow for the analysis of the success of alternative techniques such as Laser and Piezosurgery, which appear to be very promising.

Clinical and radiographic outcomes of implant-supported zirconia fixed dental prostheses with cantilever extension: A proof-of-principle study with a follow-up of at least 1 year

OBJECTIVES

To test the reliability of full zirconia implant-supported fixed dental prostheses with cantilever extension (FDPCs) after at least 1 year of function.

MATERIALS AND METHODS

Thirty-five patients in need of implant-supported single unit crowns (SUC) and FDPCs in posterior areas were enrolled. After implant placement, patients were rehabilitated with screw-retained full-zirconia FDPCs. Implant survival rate, pocket probing depth (PPD), presence/absence of bleeding on probing (BoP), and presence/absence of mechanical/technical complications were recorded. Mesial and distal radiographic marginal bone levels (mBLs) from baseline (i.e., recall appointment 3-6 months after implant loading [T0]) to the follow-up examination (i.e., latest recall appointment after at least 12 months after T0 [T1]), were calculated.

RESULTS

Thirty patients with 34 FDPCs (31 SUCs and 3 FDPs) supported by 37 implants were available for analysis after a mean loading time of 2.6 ± 1.5 years (range: 13-87 months). No implants were lost. MBLs and mean PPD values did not change statistically significantly from T0 to T1 from 0.92 mm ± 0.42 to 0.96 mm ± 0.38 (95% CI: -0.07/0.17; p = .418) and from 2.99 mm ± 0.70 to 3.27 mm ± 0.71 (95% CI: -0.11/0.68; p = .25) respectively. Peri-implant mucositis was diagnosed in 22 cases. Screw-loosening and zirconia chipping occurred 1× in 4 patients.

CONCLUSION

Within the limitations of the present proof-of-principle study, the use of full-zirconia FDPCs in posterior areas seems a valid and safe short-term treatment option.

Revealing leukocyte populations in human peri-implantitis and periodontitis using flow cytometry

OBJECTIVE

To identify, quantify, and characterize leukocyte populations in PI and periodontitis using flow cytometry.

METHODS

Fresh biopsies from human PI and periodontitis lesions were processed to a single-cell suspension. The immune cell types were identified using flow cytometry.

RESULTS

Twenty-one biopsies were obtained and analyzed corresponding to fourteen PI and seven periodontitis samples. Participants' average age was 63.95 ± 14.77 years without a significant difference between PI and periodontitis patients, the female/male ratio was 8/12, and mean PD was 8.5 ± 2.17. High similarity was found between periodontitis and PI in the main immune cell types. Out of the leukocytes, the PMN proportion was 40% in PI and 33% in periodontitis. T-cells 22% in PI and 18% in periodontitis. Similar proportions of B-cells 10% and macrophages 6% were found in PI and periodontitis. Dendritic and NK cells were found in low proportions (~ 1%) in PI and periodontitis. T-cell sub-analysis showed that CD4-positive were more prevalent than CD8-positive in both diseases (CD4/CD8 ratio of 1.2).

CONCLUSION

With the use of flow cytometry analysis, the leukocyte populations in human peri-implantitis and periodontitis were classified. In PI and periodontitis, we identified similar proportions of specific (CD4/CD8) and innate (dendritic and NK) immune cells. These results corroborate previous histological studies.

CLINICAL RELEVANCE

Flow cytometry analysis can be used to identify and quantify immune cells in PI and periodontitis, including sub-classification of T cells (CD4/8) as well as detection of cells that require multiple markers for identification (such as dendritic cells).

Marginal bone level changes around dental implants with one or two adjacent teeth - A clinical and radiographic retrospective study with a follow-up of at least 10 years

AIM

To compare mean bone level (mBL) changes around dental implants with one or two adjacent teeth after a function time of ≥10 years.

MATERIALS AND METHODS

One hundred thirty three periodontally compromised patients (PCPs) with 551 implants enrolled in supportive periodontal care (SPC) were screened. Implants were categorized either into group TIT (tooth-implant-tooth) or into group TIG (tooth-implant-gap). MBL changes from delivery of restoration (i.e., baseline) to follow-up were calculated in millimeters and compared between implants and adjacent teeth. Survival rates and the need for surgical interventions during SPC were recorded.

RESULTS

Eighty seven patients with 142 implants were re-evaluated after a mean observation time of 14.5 ± 3.5 years. The mBL at mesial implant sites in the TIT group increased -0.07 ± 0.92 mm and decreased in the TIG group 0.52 ± 1.34 mm, respectively (95% CI: 0.04/1.14, p = .037). At distal implant sites, the mBL in the TIT group increased -0.08 ± 0.84 mm and decreased 0.03 ± 0.87 in the TIG group, respectively (95% CI: -0.20/0.42, p = .48). The overall implant loss rate was 3.5% (n = 5; 2 TIT, 3 TIG), without a statistically significant difference between the two groups (95% CI: 0.18/7.07, p = .892). Tooth loss rates (TIT: 12.3%, TIG: 12.3%) were not statistically significantly different (OR = 1.00, p = .989).

CONCLUSION

High tooth and implant survival rates were observed in PCPs. The presence of one or two adjacent teeth seemed to have no impact on marginal bone level changes.

Peri-implantitis and systemic inflammation: A critical update

Peri-implantitis is an inflammatory condition induced by bacterial biofilm that affects the soft and hard tissues surrounding dental implants, compromising the success of implant therapy. Recent studies have highlighted the potential links between peri-implant health and systemic inflammation, including uncontrolled diabetes mellitus, psychological stress, cardiovascular disease, obesity, and infectious diseases such as COVID-19. As an inflammatory disease, peri-implantitis may trigger systemic inflammation by elevating circulating levels of pro-inflammatory cytokines, which could have unknown impacts on overall health. While the relationship between periodontal health and systemic conditions is better understood, the association between peri-implant disease and systemic inflammation remains unclear. Therefore, this comprehensive review aims to summarize the most recent evidence on the relationship between peri-implantitis and systemic inflammation, focusing on biological complications, microbiology, and biomarkers. This review aims to enhance our understanding of the links between peri-implantitis and systemic inflammation and promote further research in this field by discussing the latest insights and clinical implications.

Outcome indicators of non-surgical therapy of peri-implantitis: a prospective case series analysis

OBJECTIVES

This study aims to identify patient and implant indicators influencing the non-surgical therapeutic outcomes of peri-implantitis at 6 months of follow-up.

METHODS

This case series involved patients with at least one implant diagnosed with peri-implantitis according to the 2017 World Workshop criteria. Non-surgical therapy consisted of mechanical debridement of the peri-implant pockets combined with metronidazole 500 mg 3 times a day for 7 days. At baseline and at 6 months, clinical and radiographic variables were collected to calculate treatment success (probing pocket depth reduction to 5 mm without bleeding on probing or < 5 mm irrespective of bleeding on probing at all implant sites, and lack of bone loss progression). The primary outcome was treatment success (%) at 6 months. The influence of the patient and implant/prosthetic variables upon disease resolution was assessed through simple and multiple logistic regression analyses at patient and implant level, using generalized estimation equations models.

RESULTS

A total of 74 patients and 107 implants were analyzed at 6 months. Disease resolution was established in 25.7% of the patients and 24.1% of the implants. Patients with stage IV and grade C periodontitis, inadequate oral hygiene at baseline, and wide diameter (≥ 4.5 mm) presented significantly greater treatment failure, whereas smokers and former smokers demonstrated a tendency toward failure. At 6 months, there was a significant decrease in probing pocket depth and bleeding on probing of 1.08 ± 1.06 mm and 14%, respectively. Radiographically, a significant gain in marginal bone level of 0.43 ± 0.56 mm was observed.

CONCLUSION

Disease resolution after non-surgical treatment of peri-implantitis is negatively influenced by the loss of support of the adjacent periodontium, poor baseline oral hygiene, and wide diameter implants (≥ 4.5 mm).

CLINICAL RELEVANCE

This study helps to discriminate the clinical situations in which non-surgical treatment is less likely to achieve treatment success at short term.

Docosahexaenoic Acid-Loaded Nanostructured Lipid Carriers for the Treatment of Peri-Implantitis in Rats

Being the most common cause of implant failure, peri-implantitis is defined as a pathological condition associated with the occurrence of peri-implant plaque, characterized by peri-implant mucosal inflammation and progressive loss of the supporting bone tissue attributed to the persistence of pro-inflammatory cytokines. Docosahexaenoic acid (DHA), which is a type of omega-3 polyunsaturated fatty acid, is generally used for the treatment of many inflammatory diseases. However, a suitable form for dosing and its therapeutic effect on peri-implantitis remain unclear. In this study, a novel nanostructured lipid carrier (NLC) loaded with squalene and DHA was fabricated (DHA-loaded NLC). The encapsulation efficiency and drug loading efficiency values of the DHA-loaded NLC were 78.13% ± 1.85% and 28.09% ± 0.48%, respectively. The release of DHA was gradual and steady until 144 h. In addition, the free-radical-scavenging rate of DHA-loaded NLC (0.57 ± 0.03) was much higher than that of sole DHA (0.17 ± 0.003). By inhibiting nuclear factor-κB p65 nuclear translocation, DHA-loaded NLC prevented the activation of nuclear factor-κB downstream inflammatory pathways and exerted anti-inflammatory effects on macrophages. Moreover, DHA-loaded NLC showed better effects on preventing alveolar bone resorption of rat peri-implantitis model than sole DHA. Hence, DHA-loaded NLC enhanced the anti-inflammatory bioavailability of DHA, offering a novel approach for the treatment of peri-implantitis.