The effect of nicotine-containing products on peri-implant tissues: A systematic review and network meta-analysis.

INTRODUCTION: Smokers have a higher chance of developing peri-implant diseases and are therefore considered an at-risk population. Our aim was to compare peri-implant characteristics in users of electronic cigarettes (EC), waterpipes (WP), cigarettes (CS), smokeless tobacco (ST), and non-smokers (non-users of any nicotine and tobacco product; NS). METHODS: A systematic search of four electronic databases (PubMed, EMBASE, Web of Science, CENTRAL) was performed until April 2023, restricted to English language. Thirty-nine observational studies were included in the qualitative synthesis, of which 32 studies were included in a Bayesian network meta-analysis. Using a predesigned form, two researchers independently collected data about marginal bone loss (MBL), probing pocket depth (PPD), plaque index (PI), bleeding on probing (BOP), modified plaque index (mPI), probing pocket depth > 4mm (PPD>4), gingival index (GI), peri-implant sulcular fluid (PISF) volume, and TNF-α and IL-1ß levels. QUIPS and CINeMA were used to evaluate the risk of bias and certainty of evidence. RESULTS: NS had the smallest MBL. Most nicotine-containing product users had significantly higher MBL (CS, MD:1.34 CrI: 0.85, 1.79; WP, MD:1.58 CrI: 0.84, 2.35; ST, MD:2.53, CrI: 1.20, 3.87) than NS. EC did not show significant difference compared to NS (MD:0.52 CrI: -0.33, 1.36). In secondary outcomes NS were ranked in first place. Subset analysis based on smoking habit, implant duration, and maintenance control revealed no differences in ranking probability. CONCLUSION: Most nicotine-containing product users presented worse peri-implant parameters compared to non-smokers, while EC users did not show significant differences to NS in many outcomes. IMPLICATION: Alternative nicotine-containing products are gaining popularity and are often considered less harmful by the general public compared to traditional cigarettes. This is the first network meta-analysis comparing users of four nicotine-containing products and non-smokers. This study shows that CS, WP and ST have a detrimental effect on the overall health of peri-implant tissues. EC users also presented inferior parameters compared to NS, however, the difference was not significant in many outcomes. It is essential to educate patients who are using nicotine-containing products, and to provide proper maintenance and appropriate cessation support. Well-designed multi-armed studies are needed for direct comparison of different products, including heated tobacco products. Greater transparency of confounding factors is needed regarding smoking habit and oral hygiene.

Development of a quantitative preclinical screening model for implant osseointegration in rat tail vertebra.

OBJECTIVES: Functional tooth replacement and bone regeneration are parts of the daily practice in modern dentistry, but well-reproducible and relatively inexpensive experimental models are still missing. We aimed to develop a new small animal model to monitor osseointegration utilizing the combination of multiple evaluation protocols. MATERIAL AND METHODS: After cutting the tail between the C4 and C5 vertebrae in Wistar rats, costume made, parallel walled, non-threaded implants were placed into the center of the tail parallel with its longitudinal axis using a surgical guide. Osseointegration of the titanium implants was followed between 4 and 16 weeks after surgery applying axial extraction force, and resonance frequency analysis as functional tests, and histomorphometry and micro-CT as structural evaluations. RESULTS: In functional tests, we observed that both methods are suitable for the detection of the time-dependent increase in osseointegration, but the sensitivity of the pull-out technique (an approximately five times increase with rather low standard error) was much higher than that of the resonance frequency analysis. In structural evaluations, changes in the detected bone implant contact values measured by histomorphometry (yielding 1.5 times increase, with low variations of data) were more reliable than micro-CT based evaluations to screen the developments of contact between bone and implant. CONCLUSION: Our results provide evidence that the caudal vertebrae osseointegration model is useful for the preclinical evaluation of implant integration into the bone. CLINICAL RELEVANCE: The combination of the biomechanical and structural tests offers a well-reproducible small animal system that can be suitable for studying the integration of various implant materials and surface treatments.

Effect of stem cells of dental pulp origin on osseointegration of titanium implant in a novel rat vertebra model.

During that last decade a large number of experiments showed the successful application of stem cells in achieving large bone volume regeneration. On the contrary, our knowledge about the promotion of implant osseointegration by stem cell is sporadic. Recently, our research group has carried out an array of studies aiming the characterization of postnatal stem cells of dental origin. In addition, we have developed a novel quantitative model for implant osseointegration in rat tail vertebrae. In the present work we aimed to study how the implant osseointegration process is affected by mesenchymal stem cells of rat dental pulp origin (DPSC) when cells are undifferentiated or predifferentiated into osteogenic direction. Our results show that undifferentiated pulp cells inserted between the implant and the bone slow down the osseointegration process. On the other hand, pre-differentiated DPSCs do not have a similar adverse effect any more. Our data suggest that the success of mesenchymal stem cell application to promote implant osseointegration is highly dependent on the applied conditions, particularly on the parallel applicatioh of scaffolds and osteogenic components.

Function and repair of dental enamel - Potential role of epithelial transport processes of ameloblasts.

The hardest mammalian tissue, dental enamel is produced by ameloblasts, which are electrolyte-transporting epithelial cells. Although the end product is very different, they show many similarities to transporting epithelia of the pancreas, salivary glands and kidney. Enamel is produced in a multi-step epithelial secretory process that features biomineralization which is an interplay of secreted ameloblast specific proteins and the time-specific transport of minerals, protons and bicarbonate. First, "secretory" ameloblasts form the entire thickness of the enamel layer, but with low mineral content. Then they differentiate into "maturation" ameloblasts, which remove organic matrix from the enamel and in turn further build up hydroxyapatite crystals. The protons generated by hydroxyapatite formation need to be buffered, otherwise enamel will not attain full mineralization. Buffering requires a tight pH regulation and secretion of bicarbonate by ameloblasts. The whole process has been the focus of many immunohistochemical and gene knock-out studies, but, perhaps surprisingly, no functional data existed for mineral ion transport by ameloblasts. However, recent studies including ours provided a better insight for molecular mechanism of mineral formation. The secretory regulation is not completely known as yet, but its significance is crucial. Impairing regulation retards or prevents completion of enamel mineralization and results in the development of hypomineralized enamel that easily erodes after dental eruption. Factors that impair this function are fluoride and disruption of pH regulators. Revealing these factors may eventually lead to the treatment of enamel hypomineralization related to genetic or environmentally induced malformation.

[Complete attendance of a caries risk patient]. / Caries rizikópáciens komplex ellátása. Esetismertetés.

An adult caries high risk patient reported to the clinic with acute complaint. After an adequate pain control patient was motivated to participate in the required periodontal, oral surgical, conservative dental and prosthodontic treatment. Based on her DMF-index scores, periodontal and plaque indexes, and high rates for Streptococcus mutans (CRT-test), and also her inappropriate diet deriving from her financial and social standing, the 38-year-old female patient was considered as a caries high risk patient. After oral hygienic instruction, motivation, supra and subgingival scaling, and extraction fillings and root canal treatments (including revisions as well) were carried out. Finally complete functional and esthetic rehabilitation have been fulfilled by fixed restorations. Caries is a widespread disease in Hungary, affecting 98,8% of the adult population. According to recent statistics despite an improving tendency, the application of many patients with the need of an entire dental rehabilitation is expected. Besides the importance of prevention and regular controls the treatment planning and the execution of a complete dental treatment remain a rather complex task even without the presence of any systemic diseases. The patients' co-operation may be obtained after a comprehensive medical history and by means of different methods (bacterial tests, plaque indexes etc.) which demonstrate the results, to assure a sufficient and longterm outcome.

Daily use of chlorine dioxide effectively treats halitosis: A meta-analysis of randomised controlled trials.

OBJECTIVES: We aimed to conduct a systematic review on published data in order to investigate the efficacy of mouthwash products containing chlorine dioxide in halitosis. STUDY DESIGN: Systematic review and meta-analysis. METHODS: Our search was conducted on 14th October 2021. We searched the following electronic databases: MEDLINE, Embase, Scopus, Web of Science, and CENTRAL. We analysed data on adults with halitosis, included only randomised controlled trials and excluded in vitro and animal studies. The interventional groups used chlorine dioxide, and the comparator groups used a placebo or other mouthwash. Our primary outcomes were changes in organoleptic test scores (OLS) and Volatile Sulfur Compound (VSC) levels from baseline to the last available follow-up. RESULTS: We found 325 articles in databases. After the selection process, ten articles were eligible for qualitative synthesis, and 7 RCTs with 234 patients were involved in the meta-analysis. Our findings showed a significant improvement in the parameters of the chlorine dioxide group compared to the placebo group in OLS one-day data (mean difference (MD): -0.82; 95% confidence intervals (95% CIs): [-1.04 --0.6]; heterogeneity: I2 = 0%, p = 0.67); and one-week OLS data (MD: -0.24; 95% CIs: [-0.41 --0.07]; I2 = 0%, p = 0.52); and also changes in H2S one-day data (standardised mean difference (SMD): -1.81; 95% CIs: [-2.52 --1.10]); I2 = 73.4%, p = 0.02). CONCLUSION: Our data indicate that chlorine dioxide mouthwash may be a good supportive therapy in oral halitosis without known side effects.

Clear guidance to select the most accurate technologies for 3D printing dental models - A network meta-analysis✰.

OBJECTIVES: Thus far, the findings of numerous studies conducted on the accuracy of three-dimensional (3D) printed dental models are conflicting. Therefore, the aim of the network meta-analysis (NMA) is to determine the accuracy of 3D printed dental models compared with digital reference models. DATA: Studies comparing the accuracy of 3D printed full-arch dental models manufactured using different printing techniques to initial STL files were included. SOURCES: This study was registered in PROSPERO (CRD42021285863). An electronic search was performed across four databases in November 2021, and search was restricted to the English language. STUDY SELECTION: A systematic search was conducted based on a prespecified search query. 16,303 articles were pooled after the removal of the duplicates. Following study selection and data extraction, 11 eligible studies were included in the NMA in 6 subgroups. The outcomes were specified as trueness and precision and expressed as root mean square (RMS) and absolute mean deviation values. Seven printing technologies were analyzed: stereolithography (SLA), digital light processing (DLP), fused deposition modeling/fused filament fabrication (FDM/FFF), MultiJet, PolyJet, continuous liquid interface production (CLIP), and LCD technology. The QUADAS-2 and GRADE were used to evaluate the risk of bias and certainty of evidence. CONCLUSIONS: SLA, DLP, and PolyJet technologies were the most accurate in producing full-arch dental models. CLINICAL SIGNIFICANCE: The findings of the NMA suggest that SLA, DLP, and PolyJet technologies are sufficiently accurate for full-arch dental model production for prosthodontic purposes. In contrast, FDM/FFF, CLIP, and LCD technologies are less suitable for manufacturing dental models.

Patients with inflammatory bowel disease have a higher chance of developing periodontitis: A systematic review and meta-analysis.

Background and objective: Periodontitis affects up to one billion people worldwide, and has been proven to be associated with several systemic inflammatory conditions. This study investigates the specific relationship between two multifactorial diseases: Inflammatory bowel disease (IBD) and periodontitis. To thoroughly explore this issue, we investigated separately whether IBD patients have a higher chance of developing periodontitis, and equally, whether patients with periodontitis have a higher chance of developing IBD. Methods: The systematic search was performed in three databases: MEDLINE, Cochrane Trials, and Embase, up to 26 October 2021. The protocol was registered in PROSPERO. All eligible studies investigating the association between IBD and periodontitis from either direction were included. The Newcastle-Ottawa Scale was used to assess the risk of bias. As a primary outcome, we investigated the prevalence of IBD and periodontitis, and calculated the odds ratio (OR). Our secondary outcomes involved comparing the clinical periodontal outcomes of IBD patients to those of IBD-free patients. Results: The systematic search resulted in 1,715 records, 14 of which were eligible for qualitative synthesis and 8 for quantitative synthesis. On the basis of the results of the primary outcome, IBD diagnosis was associated with significantly higher odds of periodontitis: OR = 2.65 (CI: 2.09-3.36, I 2 = 0 (CI: 0-0.75)). For subgroup analysis, we investigated separately the odds in Crohn's disease (CD) patients: OR = 2.22 (CI: 1.49-3.31, I 2 = 0.05 (CI: 0-0.76)) and in ulcerative colitis (UC) patients: OR = 3.52 (CI: 2.56 to 4.83, I 2 = 0 (CI: 0-0.75)); the odds were significantly higher in all cases. Two studies investigated whether patients with periodontitis were more susceptible to IBD, and both found that periodontitis was significantly associated with the risk of subsequent UC, but not with subsequent CD. However, more studies are needed to prove an association. Conclusion: Our analysis confirmed that IBD patients have a higher chance of developing periodontitis, and are a higher risk population in dentistry. Both dentists and gastroenterologists should be aware of this relationship and should emphasize the importance of prevention even more than in the healthy population. Systematic review registration: [https://www.crd.york.ac.uk/prospero/], identifier [CRD42021286161].

Orally Administered Probiotics Decrease Aggregatibacter actinomycetemcomitans but Not Other Periodontal Pathogenic Bacteria Counts in the Oral Cavity: A Systematic Review and Meta-Analysis.

Introduction: At the initial part of the gastrointestinal tract, multiple tissues serve the normal function of food delivery. Periodontal structures are integral elements of these. When they deteriorate, it is extremely challenging to regenerate and reconstruct them. The conventional intervention for periodontal disease is scaling and root planning with the aim of reducing pathogenic bacteria. However, periodontal pathogens can rapidly recolonize treated areas. Probiotics have been proposed as novel tools for managing oral health by suppressing pathogenic bacteria through their anti-inflammatory effect, but the available data are controversial. Aim: Therefore, we performed a meta-analysis to study the effect of probiotics on periodontal pathogenic bacteria. Methods: The study was registered in PROSPERO under registration number CRD42018094903. A comprehensive literature search from four electronic databases (PubMed, Cochrane CENTRAL, Embase, and Web of Science) yielded nine eligible records for statistical analysis. Studies measuring bacterial counts in saliva and supra- and subgingival plaque were included. Bacterial counts were analyzed using standard mean difference (SMD) and by a random effects model with the DerSimonian-Laird estimation. Results: The results showed a significant decrease in the overall count of Aggregatibacter actinomycetemcomitans in the probiotic-treated group compared to the control at 4 weeks (SMD: -0.28; 95% CI: -0.56--0.01; p = 0.045) but not later. Analyzing the bacterial counts in subgroups, namely, in saliva and supra- and subgingival plaque, separately, yielded no significant difference. Probiotics had no significant effect on the overall count of Porphyromonas gingivalis at 4 weeks (SMD: -0.02; 95% CI: -0.35-0.31; p = 0.914) or later. Subgroup analysis also revealed no significant difference between treatment and control groups nor did probiotics significantly decrease the overall and subgroup bacterial counts of Prevotella intermedia, Tannerella forsythia, and Fusobacterium nucleatum. Conclusion: Our data support the beneficial effect of probiotics in reducing A. actinomycetemcomitans counts, but not of other key periodontal pathogenic bacteria in periodontal disease patients. However, due to the complex mechanism associated with periodontal disease and the limitations of the available studies, there is a further need for well-designed randomized clinical trials to assess the efficacy of probiotics.

Effects of Chlorine Dioxide on Oral Hygiene - A Systematic Review and Meta-analysis.

BACKGROUND: Effective and selective oral rinses are required in the daily medical and dental practice. Currently mouthwashes used have substantial side effects. OBJECTIVES: Our aim was to evaluate the efficacy of chlorine dioxide-containing mouthwashes in comparison with other previously established mouth rinses in healthy adults using oral hygiene indices. METHODS: This work was registered in PROSPERO (CRD42018099059) and carried out using multiple databases and reported according to the PRISMA statement. The search terms used were "chlorine dioxide" AND "oral", and only randomised controlled trials (RCTs) were included. The primary outcome was the alteration of the plaque index (PI), while the secondary outcomes were the gingival index (GI) and bacterial counts. For the risk of bias assessment, the Cochrane Risk of Bias Tool was used. Statistical analysis for data heterogeneity was performed by Q-value and I2-tests. RESULTS: 364 articles were found in the databases. After the selection process, only five RCTs were eligible for meta-analysis. Data heterogeneity was low. There were no statistical differences in effectiveness between chlorine dioxide and other effective mouth rinses in PI (0.720±0.119 vs 0.745±0.131; 95%; confidence intervals (CIs): 0.487-0.952 vs 0.489-1.001, respectively) and GI (0.712±0.130 vs 0.745±0.131; 95% CIs: 0.457-0.967 vs 0.489- 1.001, respectively) and also in bacterial counts. CONCLUSION: Chlorine dioxide reduces both plaque and gingival indices and bacterial counts in the oral cavity similar to other routinely used oral rinses, however, the evidence supporting this outcome is very limited. Therefore, further large scale RCTs are needed to decrease the risk of bias.

Sandblasting reduces dental implant failure rate but not marginal bone level loss: A systematic review and meta-analysis.

INTRODUCTION: Sandblasting is one of the oldest implant surface modifications to enhance osseointegration. Regarding its superiority over machined surface controversies still exist. Our objective was to compare implant failures (IF) and marginal bone level (MBL) changes between sandblasted and machined dental implants by a meta-analysis utilizing the available data. The PROSPERO registration number of the meta-analysis is CRD42018084190. METHODS: The systematic search was performed in Cochrane, Embase and Pubmed. Inclusion criteria included participants with neither systemic diseases, nor excessive alcohol consumption, nor heavy smoking. We calculated pooled Risk Ratio (RRs) with confidence intervals of 95% (CIs) for dichotomous outcomes (implant failure) and weighted mean difference (WMD) CIs of 95% for continuous outcomes (marginal bone level change). We applied the random effect model with DerSimonian-Laird estimation. I2 and chi2 tests were used to quantify statistical heterogeneity and gain probability-values, respectively. RESULTS: Literature search revealed 130 records without duplicates. Out of these, seven studies met the inclusion criteria and all were included in data synthesis, involving 362 sand-blasted and 360 machined implants. The results indicate that there is an 80% (RR = 0.2 95% CI:0.06-0.67; I2 = 0.0% p = 0.986) lower among sandblasted compared to machined implants after one year of use and 74% (RR = 0.26 95% CI:0.09-0.74; I2 = 0.0% p = 0.968) five years of use, respectively. In contrast, there is no significant difference in MBL (WMD:-0.10mm, 95% CI:-0.20, 0.01; p>0.05; I2 = 0.0%, p = 0.560 and WMD:-0.01mm, 95% CI:-0.12, 0.09; p>0.05; I2 = 26.2%, p = 0.258) between the two implant surfaces after one and five years of use. CONCLUSIONS: This meta-analysis reveals that sandblasting is superior over machined surface in implant failure but not in marginal bone level in healthy subjects. It also points out the need for further randomized clinical trials with large sample size for objective determination of the clinical benefits of certain implant surface modifications.

Stress and Salivary Glands.

Salivary glands produce a bicarbonate-rich fluid containing digestive and protective proteins and other components to be delivered into the gastrointestinal tract. Its function is under strict control of the autonomic nervous system. Salivary electrolyte and fluid secretion are primarily controlled by parasympathetic activity, while protein secretion is primaily triggered by sympathetic stimulation. Stress activates the hypothalamic - pituitary - adrenal axis. The peripheral limb of this axis is the efferent sympathetic/adrenomedullary system. Stress reaction, even if it is sustained for long, does not cause obvious damage to salivary glands. However, stress induces dramatic changes in the constituents of secreted saliva. Since salivary protein secretion is strongly dependent on sympathetic control, changes in saliva can be utilized as sensitive stress indicators. Some of the secreted compounds are known for their protective effect in the mouth and the gut, while others may just pass through the glands from blood plasma because of their chemical nature and the presence of transcellular salivary transporting systems. Indeed, most compounds that appear in blood circulation can also be identified in saliva, although at different concentrations. This work overviews the presently recognized salivary stress biosensors, such as amylase, cortisol, heat shock proteins and other compounds. It also demonstrates that saliva is widely recognised as a diagnostic tool for early and sensitive discovery of salivary and systemic conditions and disorders. At present it may be too early to introduce most of these biomarkers in daily routine diagnostic applications, but advances in salivary biomarker standardisation should permit their wide-range utilization in the future including safe, reliable and non-invasive estimation of acute and chronic stress levels in patients.

Mesenchymal Stem Cells of Dental Origin-Their Potential for Antiinflammatory and Regenerative Actions in Brain and Gut Damage.

Alzheimer's disease, Parkinson's disease, traumatic brain and spinal cord injury and neuroinflammatory multiple sclerosis are diverse disorders of the central nervous system. However, they are all characterized by various levels of inappropriate inflammatory/immune response along with tissue destruction. In the gastrointestinal system, inflammatory bowel disease (IBD) is also a consequence of tissue destruction resulting from an uncontrolled inflammation. Interestingly, there are many similarities in the immunopathomechanisms of these CNS disorders and the various forms of IBD. Since it is very hard or impossible to cure them by conventional manner, novel therapeutic approaches such as the use of mesenchymal stem cells, are needed. Mesenchymal stem cells have already been isolated from various tissues including the dental pulp and periodontal ligament. Such cells possess transdifferentiating capabilities for different tissue specific cells to serve as new building blocks for regeneration. But more importantly, they are also potent immunomodulators inhibiting proinflammatory processes and stimulating anti-inflammatory mechanisms. The present review was prepared to compare the immunopathomechanisms of the above mentioned neurodegenerative, neurotraumatic and neuroinflammatory diseases with IBD. Additionally, we considered the potential use of mesenchymal stem cells, especially those from dental origin to treat such disorders. We conceive that such efforts will yield considerable advance in treatment options for central and peripheral disorders related to inflammatory degeneration.

Biofilm Lysine Decarboxylase, a New Therapeutic Target for Periodontal Inflammation.

BACKGROUND: Lysine, a nutritionally essential amino acid, enters the oral cavity in gingival crevicular fluid (GCF). During oral hygiene restriction (OHR), lysine decarboxylase (LDC) in dento-gingival biofilms converts lysine to cadaverine. Lysine depletion impairs the dental epithelial barrier to bacterial proinflammatory products. Antibodies to LDC from Eikenella corrodens (Ecor-LDC) inhibit LDC activity and retard gingival inflammation in beagle dogs. Whether E. corrodens is the major source of LDC in dental biofilms and whether the lysine analog tranexamic acid (TA) inhibits LDC activity, biofilm accumulation, and GCF exudation in a human gingivitis model were examined. METHODS: Antibodies raised in goats to LDC-rich extracts from E. corrodens cell surfaces were used to inhibit Ecor-LDC and detect it in biofilm extracts using Western blots. Ecor-LDC activity was measured at pH 4.0 to 11.0 and its TA dissociation constant (Ki) at pH 7.0. Young adults used a 5% or 10% TA mouthwash three times daily during OHR for 1 week. RESULTS: Ecor-LDC antibodies and TA inhibited biofilm LDC. Ki of TA for Ecor-LDC was 940 µM. TA reduced plaque index (PI) by downshifting the PI correlation with biofilm lysine content after OHR without TA. GCF was correspondingly suppressed. However, greater TA retention in saliva partially relieved GCF suppression but not biofilm lysine depletion. CONCLUSIONS: TA slightly inhibits LDC but strongly reduces biofilm by inhibiting bacterial lysine uptake. Unfortunately, TA may impair dental epithelial attachments by also inhibiting lysine transporter uptake. Ecor-LDC inhibitors other than lysine analogs may maintain sufficient lysine levels and attachment integrity to prevent periodontal inflammation.

Bacterial lysine decarboxylase influences human dental biofilm lysine content, biofilm accumulation, and subclinical gingival inflammation.

BACKGROUND: Dental biofilms contain a protein that inhibits mammalian cell growth, possibly lysine decarboxylase from Eikenella corrodens. This enzyme decarboxylates lysine, an essential amino acid for dentally attached cell turnover in gingival sulci. Lysine depletion may stop this turnover, impairing the barrier to bacterial compounds. The aims of this study are to determine biofilm lysine and cadaverine contents before oral hygiene restriction (OHR) and their association with plaque index (PI) and gingival crevicular fluid (GCF) after OHR for 1 week. METHODS: Laser-induced fluorescence after capillary electrophoresis was used to determine lysine and cadaverine contents in dental biofilm, tongue biofilm, and saliva before OHR and in dental biofilm after OHR. RESULTS: Before OHR, lysine and cadaverine contents of dental biofilm were similar and 10-fold greater than in saliva or tongue biofilm. After 1 week of OHR, the biofilm content of cadaverine increased and that of lysine decreased, consistent with greater biofilm lysine decarboxylase activity. Regression indicated that PI and GCF exudation were positively related to biofilm lysine after OHR, unless biofilm lysine exceeded the minimal blood plasma content, in which case PI was further increased but GCF exudation was reduced. CONCLUSIONS: After OHR, lysine decarboxylase activity seems to determine biofilm lysine content and biofilm accumulation. When biofilm lysine exceeds minimal blood plasma content after OHR, less GCF appeared despite more biofilm. Lysine appears important for biofilm accumulation and the epithelial barrier to bacterial proinflammatory agents. Inhibiting lysine decarboxylase may retard the increased GCF exudation required for microbial development and gingivitis.