Bidirectional interrelationships between diabetes and periodontal diseases: an epidemiologic perspective

This review evaluates evidence for a bidirectional relationship between diabetes and periodontal diseases. A comprehensive Medline search of the post-1960 English language literature was employed to identify primary research reports of relationships between diabetes and periodontal diseases. Reports included in the review on the adverse effects of diabetes on periodontal health (DM-->PD) were restricted to those comparing periodontal health in subjects with and without diabetes. Review of adverse affects of periodontal infection on glycemic control included reports of periodontal treatment studies and follow-up observational studies in which changes in glycemic control could be assessed. Observational studies reporting DM-->PD provided consistent evidence of greater prevalence, severity, extent, or progression of at least one manifestation of periodontal diseases in the large majority of reports (supportive evidence in 44/48 total reviewed; 37/41 cross-sectional and 7/7 cohort). Additionally, there were no studies reviewed with superior design features to refute this association. Treatment studies provided direct evidence to support periodontal infection having an adverse, yet modifiable, effect on glycemic control. However, not all investigations reported an improvement in glycemic control after periodontal treatment. Additional evidence to support the effect of severe periodontitis on increased risk for poorer glycemic control comes from 2 follow-up observational studies. The evidence reviewed supports viewing the relationship between diabetes and periodontal diseases as bidirectional. Further rigorous, systematic study is warranted to establish that treating periodontal infections can be influential in contributing to glycemic control management and possibly to the reduction of the burden of complications of diabetes mellitus.     

Periodontal disease and diabetes mellitus

Periodontal disease (PD) is one of the most commonly known human chronic disorders. The relationship between PD and several systemic diseases such as diabetes mellitus (DM) has been increasingly recognized over the past decades.

Objective:

The purpose of this review is to provide the reader with knowledge concerning the relationship between PD and DM. Many articles have been published in the english and Portuguese literature over the last 50 years examining the relationship between these two chronic diseases. Data interpretation is often confounded by varying definitions of DM, PD and different clinical criteria were applied to determine the prevalence, extent and severity of PD, levels of glycemic control and diabetes-related complications.

Methods:

This paper provides a broad overview of the predominant findings from research conducted using the BBO (Bibliografia Brasileira de Odontologia), MEDLINE, LILACS and PubMed for Controlled Trials databases, in english and Portuguese languages published from 1960 to October 2012. Primary research reports on investigations of relationships between DM/DM control, PD/periodontal treatment and PD/DM/diabetes-related complications identified relevant papers and meta-analyses published in this period.

Results:

This paper describes the relationship between PD and DM and answers the following questions: 1- The effect of DM on PD, 2- The effects of glycemic control on PD and 3- The effects of PD on glycemic control and on diabetes-related complications.

Conclusions:

The scientific evidence reviewed supports diabetes having an adverse effect on periodontal health and PD having an adverse effect on glycemic control and on diabetes-related complications. Further research is needed to clarify these relationships and larger, prospective, controlled trials with ethnically diverse populations are warranted to establish that treating PD can positively influence glycemic control and possibly reduce the burden of diabetes-related complications.     

Resolution of periodontal inflammation does not guarantee improved glycemic control in type 1 diabetic subjects

Objective: The aim of this study was to find out if periodontal therapy has any effect on glycemic control of type 1 diabetes mellitus (DM).
Subjects and Methods: The periodontal health status of 65 type 1 diabetic subjects was assessed at the baseline and 8 weeks after completion of periodontal therapy. Glycemic control was assessed on both visits by measuring the percentage of glycosylated haemoglobin (GHbA1c). The change in HbA1c (ΔHbA1c) was assessed by using both a positive or negative change 0.5% and any change in HbA1c.
Results: The mean HbA1c level (±SD) of the whole study group was 8.6% (±1.5) at the baseline and 8.5% (±1.5) after treatment. Glycemic control improved during the study period in 23 subjects (35%) and worsened in 18 subjects (28%). Approximately 78% of the bleeding sites and 87% of the sites with probing depth 4 mm presented healing. ΔHbA1c associated significantly with baseline HbA1c but not with baseline periodontal health status or periodontal healing.
Conclusion: Regardless of a significant resolution of periodontal infection, a great majority of the subjects did not present any improvement in their glycemic control.     

Effects of diabetes mellitus on periodontal and peri-implant conditions: update on associations and risks

Objectives: To review the evidence for the association between diabetes and periodontal and peri-implant conditions and the impact of periodontal therapy in subjects with diabetes.
Material and Methods: A search of MEDLINE-PubMed was performed up to and including December 2007. The search was limited to clinical studies published in English. Publications on animal studies were excluded. The selection criteria included all levels of available evidence.
Results: Evidence on the association between diabetes and periodontitis supports the concept of increased severity but not extent of periodontitis in subjects with poorly controlled diabetes. Subjects with controlled diabetes do not show an increase in extent and severity of periodontitis. Periodontitis is associated with poor glycaemic control and diabetes-related complications. It is inconclusive that periodontal therapy with or without the use of antibiotics results in improvements of glycaemic control and of markers of systemic inflammation. Evidence is lacking to indicate that implant therapy in subjects with diabetes yields long-term outcomes comparable with those of non-diabetic subjects.
Conclusions: Poorly controlled diabetes may be considered a risk factor for increased severity of periodontitis. The effects of periodontal therapy on glycaemic control and systemic inflammation is not proven beyond doubt and need to be confirmed in large-scale randomized-controlled clinical trials.     

Impact of oral diseases on systemic health in the elderly: diabetes mellitus and aspiration pneumonia

Evidence is increasing that oral health has important impacts on systemic health. This paper presents data from the third National Health and Nutrition Examination Survey (NHANES III) describing the prevalence of dental caries and periodontal diseases in the older adult population. It then evaluates published reports and presents data from clinical and epidemiologic studies on relationships among oral health status, chronic oral infections (of which caries and periodontitis predominate), and certain systemic diseases, specifically focusing on type 2 diabetes and aspiration pneumonia. Both of these diseases increase in occurrence and impact in older age groups. The NHANES III data demonstrate that dental caries and periodontal diseases occur with substantial frequency and represent a burden of unmet treatment need in older adults. Our review found clinical and epidemiologic evidence to support considering periodontal infection a risk factor for poor glycemic control in type 2 diabetes; however, there is limited representation of older adults in reports of this relationship. For aspiration pneumonia, several lines of evidence support oral health status as an important etiologic factor. Additional clinical studies designed specifically to evaluate the effects of treating periodontal infection on glycemic control and improving oral health status in reducing the risk of aspiration pneumonia are warranted. Although further establishing causal relationships among a set of increasingly more frequently demonstrated associations is indicated, there is evidence to support recommending oral care regimens in protocols for managing type 2 diabetes and preventing aspiration pneumonia.     

Effects of periodontal disease on glycemic control,complications, and incidence of diabetes mellitus

Diabetes mellitus is a group of metabolic disorders with high mortality and morbidity associated with complications such as cardiovascular disease, kidney disease, and stroke. The prevalence of diabetes is 9.4% in US adults, and prevalence increases markedly with age, with 1 in 4 adults aged ≥65 years affected by diabetes. The estimated number of adults with type 2 diabetes globally almost tripled between 2002 and 2017, reflecting increases seen in the USA and elsewhere. This increase raises concerns about the increased morbidity and mortality associated with the complications of diabetes, including periodontal disease and tooth loss. There is a reciprocal adverse relationship between diabetes and periodontal disease, with diabetes as a major risk factor for periodontal disease, and in those patients with diabetes who also have periodontal disease then there are adverse effects on glycemic control and complications such as cardiovascular disease and end stage renal disease. In this review, those studies detailing the adverse effects of periodontal disease and diabetes will be discussed. Also, evidence is accumulating that periodontitis may play a role in increasing the incidence of new cases of type 2 diabetes, and possibly gestational diabetes. Of course, these studies need to be expanded to better understand the effects of periodontitis on diabetes glycemic control, complications, prediabetes, and the incidence of new cases. However, given the tremendous burden of diabetes on society, the dental profession should be proactive in preventing and treating periodontal disease, not only to preserve the dentition, but also to minimize the adverse effects of periodontitis on diabetes and its complications.     

Periodontal treatment and its effects on glycemic control: a review of the evidence

Persisting poor glycemic control has been shown to be associated with the incidence and progression of diabetes-related complications. The bulk of oral health-related research has focused on the impact of diabetes on periodontal health, yet there are several lines of evidence to support the plausibility of the notion that periodontal infections contribute to problems with glycemic control. This article reviews the body of English-language literature containing reports of clinical research that has considered the relationship between treatment of periodontal diseases and improvement in glycemic control in humans. Although there is supportive clinical and epidemiologic evidence, equivocal and contrary evidence also exists. It is concluded from this review that the quantity, breadth, and strength of evidence-based knowledge are currently insufficient to establish periodontal therapy as influential in improving glycemic control in either type 1 or type 2 diabetes. Further rigorous, systematic study of the effects of treating periodontal infection on glycemic control is warranted.     

The effect of periodontal therapy on serum TNF-α and HbA1c levels in type 2 diabetic patients

Background:  To determine the effect of non-surgical periodontal therapy on serum TNF-α and HbA1c levels in poorly and well-controlled type 2 diabetic patients.
Methods:  In total, 45 patients were enrolled in the study; 30 patients with type 2 diabetes mellitus with periodontitis (15 with poorly controlled diabetes, HbA1c ≥ 7%, group 1A and 15 with well-controlled diabetes, HbA1c < 7%, group 1B) and 15 patients that were systemically healthy with periodontitis (group 2). The plaque index, gingival index, probing depth, clinical attachment loss, gingival bleeding index, HbA1c value, and circulating TNF-α concentration were measured at baseline and three months after the non-surgical periodontal therapy.
Results:  All periodontal parameters and serum TNF-α levels were significantly decreased three months after the non-surgical periodontal therapy compared to the baseline values in all groups. The HbA1c values were significantly decreased only in well-controlled diabetic patients. We found no significant differences in the periodontal parameters or TNF-α levels at baseline and after three months between the two groups.
Conclusions:  Although non-surgical periodontal therapy eliminates local/systemic infection and inflammation via decreases in TNF-α, it is insufficient for significantly reducing HbA1c levels without strict glycaemic control in poorly controlled diabetic patients in a short time period.     

Diabetes, periodontal diseases, dental caries, and tooth loss: a review of the literature

Diabetes mellitus, is a common chronic disease, and its prevalence in the United States, particularly type 2 diabetes, is increasing. Complications associated with diabetes impose a heavy burden on many people, especially among certain minority populations. Periodontal diseases, dental caries, and tooth loss also are common conditions in the United States, but their prevalence is generally decreasing. Nevertheless, among important subgroups of the population, particularly certain minority and economically disadvantaged groups, there is a disproportionately higher burden of periodontal diseases, dental caries, and tooth loss. This article reviews the post-1960 English-language literature on the relationship between diabetes and oral health, specifically focusing on periodontal disease, dental caries, and tooth loss. Substantial evidence exists to support the role of diabetes and poorer glycemic control as important risk factors for periodontal disease. Additionally, the evidence provides support for viewing the relationship between diabetes and periodontal diseases as bidirectional. However, additional research is necessary to firmly establish that treating periodontal infections can contribute to glycemic control management and possibly to the reduction of type 2 diabetes complications. The literature does not describe a consistent relationship between type 2 diabetes and dental caries. It reports increased, decreased, and similar caries experiences between those with and without diabetes. This review suggests that currently there is insufficient evidence to determine whether a relationship between diabetes and risk for coronal or root caries exists. Most of the reviewed studies reported greater tooth loss in people with diabetes. However, the differences were slight and not significant in several of the reports. Furthermore, this review of the association between diabetes and tooth loss reveals that valid population-based evidence generalizable to the US population is sparse. Further investigations of the association of diabetes with dental caries and tooth loss are warranted. If adverse effects of diabetes on dental caries and/or tooth loss are substantiated, the results of such studies would help design intervention studies to prevent or reduce the occurrence of dental caries and tooth loss in people with diabetes. These results also may affect existing clinical practice protocols and promote new public policy related to diabetes.     

Periodontal diseases and health: Consensus Report of the Sixth European Workshop on Periodontology

Introduction: The remit of this group was to update the knowledge base on periodontal diseases and health.
Material and Methods: The literature was systematically searched and critically reviewed in five specific topics.
Results: Prevalence of periodontitis: The data suggest a trend towards a lower prevalence of periodontitis in recent years.
Adverse pregnancy outcome: The findings indicate a likely association between periodontal disease and an increased risk of adverse pregnancy outcomes. There is no evidence that treating periodontal disease decreases the rate of adverse pregnancy outcomes.
Prevalence and distribution of periodontal pathogens: Genetic analysis of bacteria has demonstrated an unanticipated diversity within species. Carriage rates and particular subsets of these species vary between ethnic groups. Few of these differences can be related to differences in disease prevalence.
Diabetes mellitus: Evidence on the association supports the concept of increased severity but not extent of periodontitis in subjects with poorly controlled diabetes. It is inconclusive that periodontal treatment results in improved metabolic control.
Cardiovascular diseases: Evidence suggests that having periodontitis contributes to the total infectious and inflammation burden and may contribute to cardiovascular events and stroke in susceptible subjects. The impact of periodontal therapy must be further investigated.     

Relationship between periodontal parameters and Behçet's disease and evaluation of different treatments for oral recurrent aphthous stomatitis

Background and Objective:  The highest prevalence of Behçet's disease (BD) has been reported in Turkey, and therefore research of relations between BD and other disorders have become important in the Turkish population. Since oral aphthous ulcers impair tooth brushing, reducing complaints about aphthous ulcers will motivate the patient to maintain better oral hygiene performance and will thus reduce plaque accumulation and periodontal scores. The purpose of this controlled case study was to evaluate the relationship between the severity of periodontal scores and Behçet's disease, and to compare the treatment modalities with neodymium-doped yttrium aluminium garnet (Nd:YAG) laser and medication on the recurrent aphthous ulcers in BD patients by considering the degree of pre- and post-treatment pain, discomfort and functional complications.
Material and Methods:  The periodontal status of 28 BD patients was evaluated according to periodontal indices. The BD patients were also assessed for clinical severity score as described previously. Levels of pre- and post-treatment pain and functional complications were assessed at patient visits on days 1, 4 and 7.
Results:  Periodontal indices, the number of oral ulcers and the daily frequency of tooth brushing were related to the severity scores of BD ( p  < 0.001). The results indicated that BD patients treated with the Nd:YAG laser had less post-treatment pain and fewer functional complications and reported immediate relief of pain and faster healing ( p  < 0.001).
Conclusion:  Our results suggest that periodontal status is worse in BD patients and is associated with disease severity; also, the Nd:YAG laser has better patient acceptance, shorter treatment time and lower rates of pain and post-treatment adverse events among BD patients with oral recurrent aphthous stomatitis.     

Effect of antimicrobial periodontal treatment and maintenance on serum adiponectin in type 2 diabetes mellitus

Aims: The aims of this study were to evaluate the effect of mechanical periodontal treatment with local application of minocycline (APT) on serum adiponectin as a marker of insulin resistance improvement in type 2 diabetes mellitus (T2DM) patients and to investigate if effect of APT on serum adiponectin level was sustained by periodontal maintenance (PM).
Material and Methods: Twenty-seven T2DM patients were randomly assigned into test or control groups. Test received scaling with ultrasonic devices at baseline and APT biweekly for 2 months while control received scaling at baseline and mechanical tooth cleaning (MPT) at the same interval. At 6 months, all patients received mechanical tooth cleaning as PM. Periodontal examination and blood measurements were performed at baseline, 4 and 9 months.
Results: Adiponectin concentrations in test had significantly increased by 31.4% after APT ( p =0.024) and by 30.4% after PM ( p =0.002) compared with baseline. The percentage of 4 mm probing depths (PD) had shown 8.3% and 9.3% reduction after APT and PM ( p =0.046, 0.02) in test while 5.0% reduction after MPT in control group ( p =0.031).
Conclusions: Our results suggested that APT and PM not only improve periodontal disease but also increase serum adiponectin in T2DM patients.     

Diabetes mellitus and periodontal diseases

BACKGROUND: The purpose of this review is to provide the reader with practical knowledge concerning the relationship between diabetes mellitus and periodontal diseases. Over 200 articles have been published in the English literature over the past 50 years examining the relationship between these two chronic diseases. Data interpretation is often confounded by varying definitions of diabetes and periodontitis and different clinical criteria applied to prevalence, extent, and severity of periodontal diseases, levels of glycemic control, and complications associated with diabetes. METHODS: This article provides a broad overview of the predominant findings from research published in English over the past 20 years, with reference to certain "classic" articles published prior to that time. RESULTS: This article describes current diagnostic and classification criteria for diabetes and answers the following questions: 1) Does diabetes affect the risk of periodontitis, and does the level of metabolic control of diabetes have an impact on this relationship? 2) Do periodontal diseases affect the pathophysiology of diabetes mellitus or the metabolic control of diabetes? 3) What are the mechanisms by which these two diseases interrelate? and 4) How do people with diabetes and periodontal disease respond to periodontal treatment? CONCLUSIONS: Diabetes increases the risk of periodontal diseases, and biologically plausible mechanisms have been demonstrated in abundance. Less clear is the impact of periodontal diseases on glycemic control of diabetes and the mechanisms through which this occurs. Inflammatory periodontal diseases may increase insulin resistance in a way similar to obesity, thereby aggravating glycemic control. Further research is needed to clarify this aspect of the relationship between periodontal diseases and diabetes.     

Serum sCD14, polymorphism of CD14−260 and periodontal infection

Background and Aims:  CD14 is a co-receptor involved in the recognition of Gram-negative and positive bacteria. Infections are known to influence serum sCD14 levels, and CD14 gene promoter polymorphism (CD14 C−260T) has been reported to be associated with many infectious diseases. Our aim was to investigate whether serum sCD14 concentration is associated with periodontal infection and the CD14⁻²⁶⁰ genotype.
Subjects and Methods:  The periodontal status of 56 subjects with chronic periodontitis and 28 controls was clinically examined. Serum sCD14 concentration was analyzed using ELISA and CD14⁻²⁶⁰ genotype using polymerase chain reaction (PCR).
Results:  The mean concentration of sCD14 in serum was significantly higher in subjects with periodontitis than in control subjects (4.9  μ g ml⁻¹ vs 3.8  μ g ml⁻¹, P  < 0.001). Serum sCD14 concentration associated significantly with the extent of advanced periodontal disease. In a regression analysis including both subject groups, the CD14⁻²⁶⁰ genotype was a significant determinant for serum sCD14 concentration. After stratification by periodontal health status (periodontitis vs controls), the influence of the CD14⁻²⁶⁰ genotype on serum sCD14 concentration was seen only in the control group.
Conclusions:  Periodontal infection is associated with the serum concentration of sCD14. Moderate to severe periodontal infection overshadows the influence of the genotype on serum sCD14 concentration.     

Analysis of the association of polymorphism in the osteoprotegerin gene with susceptibility to chronic kidney disease and periodontitis

Background and Objective:  Chronic kidney disease (CKD) is a complex disorder, which results in several complications involving disturbance of mineral metabolism. Periodontal disease is an infectious disease that appears to be an important cause of systemic inflammation in CKD patients. Periodontal disease is characterized by clinical attachment loss (CAL) caused by alveolar bone resorption around teeth, which may lead to tooth loss. Osteoprotegerin (OPG) is a key regulator of osteoclastogenesis. Polymorphisms are the main source of genetic variation, and single nucleotide polymorphisms (SNPs) have been reported as major modulators of disease susceptibility. The aim of this study was to investigate the association of a polymorphism located at position –223 in the untranslated region of the OPG gene, previously known as –950, with susceptibility to CKD and periodontal disease.
Material and Methods:  A sample of 224 subjects without and with CKD (in hemodialysis) was divided into groups with and without periodontal disease. The OPG polymorphism was analyzed by polymerase chain reaction and restriction fragment length polymorphism.
Results:  No association was found between the studied OPG polymorphism and susceptibility to CKD or periodontal disease.
Conclusion:  It was concluded that polymorphism OPG –223 (C/T) was not associated with CKD and periodontal disease in a Brazilian population. Studies on other polymorphisms in this and other genes of the host response could help to clarify the involvement of bone metabolism mediators in the susceptibility to CKD and periodontal disease.     

IL-6−174 genotype associated with the extent of periodontal disease in type 1 diabetic subjects

Aim: The aim of this study was to investigate whether genetic polymorphism in certain cytokine and receptor molecule genes and diabetic status associate with the extent of periodontal disease in type 1 diabetes mellitus (DM).
Material and Methods: Eighty patients with type 1 DM participated. Visible plaque, bleeding on probing (BOP), probing pocket depth (PD) and attachment level (AL) were examined clinically and glycosylated haemoglobin (HbA1c) levels were used to assess the glycemic control of DM. CD-14, IL-6, TNF- α , IL-10, IL-1 α , IL-1 β and TLR-4 gene polymorphisms were studied using the polymerase chain reaction (PCR).
Results: The 3-year HbA1c was good (<7.5%) in 16%, acceptable (7.5–8.5%) in 36% and poor (>8.5%) in 48% of the subjects. IL-6⁻¹⁷⁴ genotype and 3-year GHbA1c associated significantly with BOP and PD4 mm, subjects with the GG genotype of the IL-6⁻¹⁷⁴ exhibiting more severe periodontal disease than those with the GC/CC genotype. After stratification by IL-6 genotype, associations between the extent of periodontal disease and 3-year HbA1c levels remained significant in subjects carrying the GC/CC but not the GG genotype.
Conclusions: In addition to the HbA1c level, the IL-6⁻¹⁷⁴ genotype is a significant susceptibility factor for periodontal disease among type 1 diabetics.     

Change in periodontitis during pregnancy and the risk of pre-term birth and low birthweight

Aim: Determine whether periodontitis progression during pregnancy is associated with adverse birth outcomes.
Methods: We used clinical data and birth outcomes from the Obstetrics and Periodontal Therapy Study, in which randomly selected women received periodontal treatment before 21 weeks of gestation ( N =413) or after delivery (410). Birth outcomes were available for 812 women and follow-up periodontal data for 722, including 75 whose pregnancies ended <37 weeks. Periodontitis progression was defined as 3 mm loss of clinical attachment. Birth outcomes were compared between non-progressing and progressing groups using the log rank and t tests, separately in all women and in untreated controls.
Results: The distribution of gestational age at the end of pregnancy ( p >0.1) and mean birthweight (3295 versus 3184 g, p =0.11) did not differ significantly between women with and without disease progression. Gestational age and birthweight were not associated with change from baseline in percentage of tooth sites with bleeding on probing or between those who did versus did not progress according to a published definition of disease progression ( p >0.05).
Conclusions: In these women with periodontitis and within this study's limitations, disease progression was not associated with an increased risk for delivering a pre-term or a low birthweight infant.     

Role of systemic and local administration of selective inhibitors of cyclo-oxygenase 1 and 2 in an experimental model of periodontal disease in rats

Background and Objective:  Periodontal disease is an inflammatory condition of tooth-supporting tissues. Arachidonic acid metabolites have been implicated in development of periodontal disease, especially those derived from the cyclo-oxygenase (COX) pathway. This study investigated the role of inhibitors of cyclo-oxygenases (COX-1 and COX-2) in a model of periodontal disease in rats.
Material and Methods:  A ligature was placed around the molar of rats. Losses of fiber attachment and of alveolar bone were measured morphometrically in histologically prepared sections. Infiltration of cells into gingival tissue surrounding the ligated tooth was also determined.
Results:  Systemic and local administration of non-selective and selective COX-2 inhibitors, preventively, resulted in significant reduction of the losses of fiber attachment and alveolar bone, as well as decreased leukocyte numbers in gingival tissue. Preventive selective inhibition of COX-1 was as effective as COX-2 inhibition in reducing local fiber attachment loss and cell migration, but did not prevent alveolar bone loss.
Conclusion:  Our results provide evidence for participation of COX-1 and COX-2 in early stages of periodontal disease in rats. Furthermore, local administration of COX inhibitors reduced the signs of periodontal disease to the same extent as systemic treatment. Therapeutic approaches incorporating locally delivered anti-inflammatory drugs could be of benefit for patients suffering from periodontal disease.     

Utility of PDL progenitors for in vivo tissue regeneration: a report of 3 cases

Objective:  Periodontal disease is an inflammatory disorder with widespread morbidities involving both oral and systemic health. The primary goal of periodontal treatment is the regeneration of the lost or diseased periodontium. In this study, we retrospectively examined feasibility and safety of reconstructing the periodontal intrabony defects with autologous periodontal ligament progenitor (PDLP) implantation in three patients.
Materials and methods:  In this retrospective pilot study, we treated 16 teeth with at least one deep intrabony defect of probing depth (PD) ≥ 6 mm with PDLP transplantation and evaluated clinical outcome measures in terms of probing depth, gingival recession and attachment gain for a duration of 32–72 months. Furthermore, we compare PDLPs with standard PDL stem cells (PDLSCs) and confirmed that PDLPs possessed progenitor characters.
Results:  Clinical examination indicated that transplantation of PDLPs may provide therapeutic benefit for the periodontal defects. All treated patients showed no adverse effects during the entire course of follow up. We also found that PDLPs were analogous to PDLSCs in terms of high proliferation, expression of mesenchymal surface molecules, multipotent differentiation, and in vivo tissue regain. However, PDLPs failed to express scleraxis, a marker of tendon, as seen in PDLSCs.
Conclusions:  This study demonstrated clinical and experimental evidences supporting a potential efficacy and safety of utilizing autologous PDL cells in the treatment of human periodontitis.