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Background: Although retrograde peri-implantitis (RPI) is not a common sequela of dental implant surgery, its prevalence has been reported in the literature to be 0.26%. Incidence of RPI is reported to increase to 7.8% when teeth adjacent to the implant site have a previous history of root canal therapy, and it is correlated with distance between implant and adjacent tooth and/or with time from endodontic treatment of adjacent tooth to implant placement. Minimum 2 mm space between implant and adjacent tooth is needed to decrease incidence of apical RPI, with minimum 4 weeks between completion of endodontic treatment and actual implant placement. The purpose of this study is to compile all available treatment modalities and to provide a decision tree as a general guide for clinicians to aid in diagnosis and treatment of RPI., Methods: Literature search was performed for articles published in English on the topic of RPI. Articles selected were case reports with study populations ranging from 1 to 32 patients. Any case report or clinical trial that attempted to treat or rescue an implant diagnosed with RPI was included., Results: Predominant diagnostic presentation of a lesion was presence of sinus tract at buccal or facial abscess of apical portion of implant, and subsequent periapical radiographs taken demonstrated a radiolucent lesion. On the basis of case reports analyzed, RPI was diagnosed between 1 week and 4 years after implant placement. Twelve of 20 studies reported that RPI lesions were diagnosed within 6 months after implant placement. A step-by-step decision tree is provided to allow clinicians to triage and properly manage cases of RPI on the basis of recommendations and successful treatments provided in analyzed case reports. It is divided between symptomatic and asymptomatic implants and adjacent teeth with vital and necrotic pulps., Conclusions: Most common etiology of apical RPI is endodontic infection from neighboring teeth, which was diagnosed within 6 months after implant placement. Most common findings, radiographically and clinically, are lesions around implant apex and sinus tract. A small number of implants did not improve with treatment. Decision tree provides a path to diagnose and treat lesions to facilitate their management. Further studies are needed to focus on histologic data around periapical microbiota to establish specific etiology and differential diagnoses compared with marginal peri-implantitis and other implant-related conditions.

Background: The use of nanoparticles of graft materials may lead to breakthrough applications for periodontal regeneration. However, due to their small particle size, nanoparticles may be eliminated from periodontal defects by phagocytosis. In an attempt to improve nanoparticle retention in periodontal defects, the present in vivo study uses scanning electron microscopy (SEM) to evaluate the potential of micrograft particles of β-tricalcium phosphate (β-TCP) to enhance the binding and retention of nanoparticles of hydroxyapatite (nHA) on EDTA-treated and non-treated root surfaces in periodontal defects after 14 days of healing., Methods: Sixty patients having at least two hopeless periodontally affected teeth designated for extraction were randomly divided into four treatment groups (15 patients per group). Patients in group 1 had selected periodontal intrabony defects grafted with nHA of particle size 10 to 100 nm. Patients in group 2 were treated in a similar manner but had the affected roots etched for 2 minutes with a neutral 24% EDTA gel before grafting of the associated vertical defects with nHA. Patients in group 3 had the selected intrabony defects grafted with a composite graft consisting of equal volumes of nHA and β-TCP (particle size 63 to 150 nm). Patients in group 4 were treated as in group 3 but the affected roots were etched with neutral 24% EDTA as in group 2. For each of the four groups, one tooth was extracted immediately, and the second tooth was extracted after 14 days of healing for SEM evaluation., Results: Fourteen days after surgery, all group 1 samples were devoid of any nanoparticles adherent to the root surfaces. Group 2 showed root surface areas 44.7% covered by a single layer of clot-blended grafted particles 14 days following graft application. After 14 days, group 3 samples appeared to retain fibrin strands devoid of grafted particles. Immediately extracted root samples of group 4 had adherent graft particles that covered a considerable area of the root surfaces (88.6%). Grafted particles appeared to cover all samples in a multilayered pattern. After 14 days, the group 4 extracted samples showed multilayered fibrin-covered nano/micro-sized graft particles adherent to the root surfaces (78.5%)., Conclusion: The use of a composite graft consisting of nHA and microsized β-TCP after root surface treatment with 24% EDTA may be a suitable method to improve nHA retention in periodontal defects with subsequent graft bioreactivity.

Background: The present study was designed to determine whether exclusion of the gingival connective tissue (CT) and periosteum with contained stem cells has a positive or negative effect on periodontal regeneration by comparing the use of a novel modified perforated collagen membrane with a traditional cell occlusive barrier membrane., Methods: Twenty non-smoking patients with severe chronic periodontitis were included in the study. Single deep intrabony defects from each of the patients were randomly divided into two groups, as follows: occlusive bovine collagen membranes (OM control group, 10 sites) and modified perforated bovine collagen membranes (MPM test group, 10 sites). Plaque index, gingival index, probing depth (PD), clinical attachment level (CAL), defect base level (DBL), and crestal bone level (CBL) were measured at baseline and were reassessed at 6 and 9 months after therapy to evaluate the quantitative changes in the defect., Results: At 6- and 9-month observation periods, the MPM-treated sites showed a statistically significant improvement in PD reduction and CAL gain compared with the OM control group. DBL was significantly reduced with no significant difference between the two groups at 6- and 9-month observation periods. CBL was significantly higher in the MPM group when compared with that of the OM group at both observation periods. The postoperative differences between the two groups were 2 and 1.7 mm at 6 and 9 months, respectively, in favor of the MPM-treated sites., Conclusions: The present study demonstrated enhanced clinical outcomes when using novel MPMs compared to OMs in guided tissue regeneration procedures. These results may be affected by the penetration of gingival CT contained stem cells and periosteal cells and their differentiation into components of the attachment apparatus.

Background: The objective of this study is to evaluate micro and nano-hydroxyapatite (NHA) blended clot adhesion to citric acid-conditioned peri-implantitis-affected surfaces., Methods: Forty hopeless implants with peri-implantitis designated for removal were included in this study. Implants were divided into eight groups of five each: group 1 (G1) test areas were coated with hydroxyapatite of a microparticle size (MHA); group 2 (G2) test areas were coated with NHA; group 3 (G3) implants were coated with MHA after surface conditioning using citric acid; group 4 (G4) samples were treated in the same manner as in G3 except for the use of NHA; group 5 (G5) samples were coated without surface treatment with MHA mixed with whole human blood; group 6 (G6) implant samples were treated in the same manner as in G5 except for the use of NHA; group 7 (G7) implant samples were treated in the same way as in G5 plus surface conditioning using citric acid; and group 8 (G8) samples were treated in the same manner as in G7 except for the use of NHA. All implants in all groups were agitated for 3 minutes in phosphate-buffered saline. All samples were prepared for scanning electron microscopy evaluation., Results: G1 and G2 non-etched implants coated with MHA or NHA sizes were devoid of any bone particle adhesion to the peri-implantitis-affected surfaces. Contrary to the lack of microparticle adhesion to the root surface that was seen in G3, G4 acid-treated and NHA-coated samples revealed nearly complete coverage of the peri-implantitis-affected parts by the graft material. G5 non-etched, clot-blended MHA showed some areas of clot-blended graft adhesion covering 6.7% of the examined surfaces. G6 non-etched, clot-blended NHA showed NHA retention within the fibrin strands in areas where the implant surface pores were exposed (24.3%). G7 acid-treated and clot-blended MHA-treated implant surfaces showed partial coverage of the implant surface with detached fibrin clot-blended graft material (31.4%). G8 acid-treated and NHA clot-blended graft-coated implants showed complete coverage of the implant surface by the clot-blended graft material (93.4%)., Conclusion: Peri-implantitis-affected surface conditioning with citric acid improves NHA-blended clot adhesion to titanium implant surfaces.

Background: Enamel matrix derivative (EMD) is used during periodontal surgery for the regeneration of periodontal tissue. It consists of the amelogenin fraction of porcine enamel matrix (AMEL) suspended in a vehicle of propylene glycol alginate (PGA). EMD-treated sites appear to heal with less inflammation. It has been suggested that antimicrobial properties of EMD might account for improved healing in vivo. The objectives of this study were: 1) to determine the antibacterial effects of EMD on the periodontal pathogen Porphyromonas gingivalis and 2) to establish the component(s) of EMD that are responsible for this effect., Methods: The antimicrobial effects were determined in vitro using the broth dilution assay. P. gingivalis at a starting inoculum of 10(9) colony forming units/ml was treated with EMD, AMEL, and PGA in Hank's balanced salt solution (HBSS) for 1, 3, and 24 hours. The CFU/ml of P. gingivalis recovered on enriched Brucella blood agar was determined at 6 and 10 days., Results: EMD (containing AMEL and PGA) or PGA alone eliminated recoverable CFUs of P. gingivalis. Interestingly, AMEL in HBSS increased recoverable CFUs from 8.62 log CFU/ml to 8.93 log CFU/ml. Further analysis of the dose response at concentrations of 0.3, 3, and 30 mg/ml of AMEL in HBSS revealed that only 30 mg/ml (clinical concentration) increased CFUs of P. gingivalis relative to baseline (from 8.8 log CFU/ml to 9.2 log CFU/ml in 3 hours). Additionally, AMEL was compared to a protein control bovine serum albumin (BSA) to determine whether this effect was unique to AMEL. A marked increase in recoverable CFUs occurred with the AMEL (increasing from 8.8 log CFU/ml to 9.47 log CFU/ml), but not with BSA., Conclusions: EMD possesses antimicrobial properties that can be attributed to the propylene glycol alginate vehicle. The amelogenin fraction of porcine enamel matrix in enamel matrix derivative (i.e., AMEL) is not antibacterial for P. gingivalis and was shown to increase recoverable CFUs.

Background: Gingival crevicular fluid (GCF) biomarkers associated with bone resorption may be useful to determine periodontal disease status and response to therapy. The pyridinoline cross-linked carboxy-terminal telopeptide of type I collagen (ICTP), a bone-specific degradation product, and interleukin 1-beta (IL-1), a potent bone-resorptive cytokine, have both been associated with periodontal disease activity. Minocycline is a tetracycline derivative possessing antimicrobial effects on periodontal pathogens and inhibitory properties on matrix metalloproteinases (MMPs) associated with tissue destruction. The aim of this study was to evaluate the effect of periodontal treatment in the form of scaling and root planing (SRP) and locally administered minocycline microspheres on the GCF levels of ICTP and IL-1., Methods: Forty-eight chronic periodontitis patients were randomly assigned to 2 groups (SRP plus subgingival application of vehicle control [SRP + V], or SRP plus subgingival application of minocycline microspheres [SRP + M]) and monitored at 8 sites per subject at baseline and 1, 3, and 6 months. Four shallow (PD < or = 3 mm) and 4 deep (PD > or = 5 mm) sites were evaluated for both marker levels and for probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP). Eight periodontally healthy control subjects with no probing depths >3 mm and no loss of attachment were also monitored at the same time intervals. GCF levels of ICTP and IL-1 were determined using radioimmunoassay and enzyme-linked immunosorbent assay techniques, respectively., Results: Significant differences (P<0.001) in GCF levels of ICTP and IL-1 were found between deep and shallow sites at all time points in both treatment groups. In addition, healthy subjects demonstrated significantly reduced levels of both markers compared to both shallow and deep sites in periodontitis patients (P <0.001). Only the SRP + M treated patients exhibited significant reductions (P <0.05) in both ICTP and IL-1 levels 1 month after treatment. Furthermore, the SRP + M group demonstrated significantly lower IL-1 levels (P <0.02) at 1 month compared to the SRP + V group., Conclusions: Results of this study indicate that GCF levels of ICTP and IL-1 correlate with clinical measures of periodontal disease and may aid in assessing disease status and response to periodontal therapy. Furthermore, local administration of minocycline microspheres led to a potent short-term reduction in GCF IL-1 levels. Additional studies are needed to address whether repeated administration of scaling and root planing along with minocycline microspheres will achieve long-term reductions in GCF ICTP and IL-1 levels.

Background: Biochemical markers harvested from gingival crevicular fluid (GCF) may be useful to identify and predict periodontal disease progression and to monitor the response to treatment. C-telopeptide pyridinoline cross-links (ICTP), a host-derived breakdown product specific for bone, and interleukin-1beta (IL-1), a potent bone-resorptive cytokine, have been associated with periodontal tissue destruction. The aim of this study was to examine the effect of non-surgical periodontal therapy on GCF levels of ICTP and IL-1., Methods: Twenty-five chronic periodontitis subjects were monitored at 8 sites per subject at baseline prior to scaling and root planing and 1, 3, and 6 months after therapy. Four shallow (probing depths < 4 mm) and 4 deep (probing depths > or = 5 mm) sites were monitored for both marker levels and clinical parameters. GCF was collected for 30 seconds on paper strips, and levels of ICTP and IL-1 were determined using radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA) techniques, respectively. Clinical measurements included probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP)., Results: Deep sites exhibited significantly (P<0.001) higher ICTP and IL-1 levels compared to shallow sites at all time intervals. ICTP demonstrated a stronger association to clinical parameters than IL-1 including a modest correlation (r = 0.40, P<0.001) between ICTP and attachment loss. Significant improvements in PD, CAL, and BOP were observed at 1, 3, and 6 months in all sites (P<0.01). However, non-surgical mechanical therapy did not significantly reduce ICTP and IL-1 levels over the 6-month period. Further examination of subjects based on smoking status revealed that ICTP levels were significantly reduced at 3 and 6 months and IL-1 levels reduced at 3 months among non-smokers only., Conclusions: A single episode of non-surgical mechanical therapy did not significantly reduce biochemical markers associated with bone resorption in patients exhibiting chronic periodontitis. Future longitudinal studies are warranted to specifically evaluate the relationship between C-telopeptide pyridinoline cross-links and periodontal disease progression.

Over the past 30 years, research has validated the success of osseointegrated implants as a viable alternative to fixed or removable prosthetic restorations. Periodontists are extensively trained in surgical procedures to treat and maintain patients with edentulous and partially edentulous arches. They also have a primary role in treatment planning and maintenance therapy. Thus, periodontists routinely integrate endosseous implants into periodontal therapy. This paper was prepared by the Research, Science and Therapy Committee of the American Academy of Periodontology and is intended to inform the dental profession regarding the utility of endosseous dental implants in the treatment of full and partial edentulism.

Background: The purpose of this longitudinal study was to determine the clinical status and the composition of the subgingival microbiota of dental implants and natural teeth in patients with a history of periodontitis., Methods: Twenty-five partially edentulous patients treated for moderate to advanced adult periodontitis and having a total of 42 implants participated in this 3-year study. The assessment of clinical status was done 1, 2, and 3 years after prosthetic loading (T1, T2, and T3, respectively). Clinical parameters evaluated included probing depth (PD), clinical attachment level (CAL), gingival index (GI), and plaque index (PI). The subgingival microbiota at peri-implant and periodontal sites were analyzed at T1 and T2., Results: No significant difference in clinical parameters between implants and teeth and within the 2 groups between different time points was observed through the study. PD and CAL measurements of sampled periodontal and peri-implant sites did not show any statistically significant difference through the study and between the 2 groups. PI of sampled periodontal sites showed a statistically significant improvement during the study. From the morphological observation of the subgingival microbiota, a significant difference in the composition of motile rods between implants and teeth was found at T1. There were no differences detected in the subgingival microbiota, culturally identified at peri-implant and periodontal sites for the duration of the study., Conclusions: In conclusion, implants were colonized by the indigenous periodontal microbiota and were well maintained in patients with a history of periodontitis. No significant association between progressing or non-progressing periodontal or peri-implant sampled sites in terms of loss of attachment and infection with at least one of the searched periodontal pathogens was found, suggesting that the presence of putative periodontopathogens at peri-implant and periodontal sites may not be associated with future attachment loss or implant failure.

This study examined for 3 years the changes in periodontal status and the possible correlations with selected subgingival microbiota and diabetic conditions in a group of 16 insulin-dependent diabetes mellitus (IDDM, JD) patients as compared with their 16 healthy cohabiting siblings (HS). JD patients were monitored every 3 months for levels of glycosylated hemoglobin (HbA1C). Clinical and microbiological parameters were measured 6 weeks before drawing blood to determine levels of HbA1C. Periodontal parameters were measured at baseline (TO), year 2 (T2), year 3 (T3) and included: probing depth (PD), attachment level (AL), sulcus bleeding index (SBI), and plaque index (PI). Two sites in each patient were selected for microbial samples: a mesio-facial aspect of the maxillary right first molar (defined as constant site, CS) and a site with the greatest probing depth (defined as deepest site, DS). Microbial samples were analyzed by culture techniques. No significant differences in clinical parameters were found between diabetics and healthy siblings at any examination. The SBI in the non-diabetic group at T2 and at T3 was significantly lower than at baseline. PD and AL of constant sites in the diabetic group at T3 were significantly higher than baseline. There was a significant increase in Prevotella intermedia at T3 as compared with baseline for deepest sites in the diabetic group. Cluster analysis revealed, in a former study, two clusters (IV and V) at baseline which were significantly different from the overall mean regarding composition of Porphyromonas gingivalis and Capnocytophaga spp. They were not significantly different for periodontal parameters from TO to T3. These data would suggest no significant differences in clinical parameters between the diabetics and non-diabetic siblings throughout this 3-year longitudinal study.

The periodontal status and subgingival microflora of insulin-dependent juvenile diabetic (JD) patients (n = 16, mean age = 11.3) were compared with that of their non-diabetic cohabiting healthy siblings (HS, n = 16, mean age = 13.2). JD patients were monitored every 3 months for levels of glycosylated hemoglobin (HbA1c) and clinical and microbial parameters were measured 6 weeks before drawing blood for levels of HbA1c (M% = 8.76). Clinical indices, measured for the entire permanent dentition, included: probing depth (PD), attachment level (AL), sulcus bleeding index (SBI), and plaque index (PI). Subgingival plaque samples were obtained at 2 sites from each subject; whenever possible, the site with the deepest probing depth and the mesial aspect of the maxillary right first molar were used. Microbial analyses were determined by cultural characteristics and biochemical tests. No significant differences were detected in any of the clinical indices for the entire dentition. The mean AL for JD sites was 2.32 +/- 0.83 mm and for HS sites was 2.2 +/- 0.85 mm. Mean percentage of total cultivable anaerobic microflora included Capnocytophaga spp. (JD, 13.21%; HS, 11%) and Porphyromonas gingivalis (JD, 5.1%; HS, 7.9%). Differences between the two groups were not statistically significant. When cluster analysis was performed on sampled sites, one cluster group in JD patients showed significantly elevated P. gingivalis and lower Capnocytophaga spp. levels as compared to the overall mean. The clinical parameters of this cluster were characterized by statistically significant greater loss of attachment and probing depth. These data would suggest few differences between JD patients and their HS in this population.

The aim of this study was to examine the subgingival microflora associated with failing implants, and to determine their susceptibility to commonly used antibiotics in periodontal therapy and dental practice. Thirteen partially edentulous patients with 19 failing implants were selected. Clinical examination included probing depth, attachment level, gingival index, plaque index, and radiographic analyses. Two subgingival plaque samples were taken from each failing implant and analyzed for microbial composition. Fusobacterium nucleatum, Porphyromonas gingivalis, and Prevotella intermedia were the prevalent cultivable microflora. Antimicrobial susceptibility of isolates was determined by the agar dilution technique. Antibacterial activity of penicillin G, amoxicillin, amoxicillin-clavulanate, and the combination amoxicillin-metronidazole was significantly higher than with other antibiotics tested. These data indicated that the commonly-used antibiotics were highly effective against bacteria isolated around failing implants, which would suggest the use of these antibiotics to control peri-implant infections.

Nine stable cardiovascular disease patients were evaluated in a double-blind cross-over trial during periodontal surgery using 2% lidocaine with epinephrine 1:100,000 or lidocaine alone. In the lidocaine with epinephrine group, epinephrine levels increased from 198 +/- 54 pg/ml to 592 +/- 166 pg/ml at 2 minutes post-injection. In the lidocaine alone group, epinephrine levels increased from a baseline of 115 +/- 34 pg/ml to 150 +/- 34 pg/ml at 2 minutes post-injection. Despite these elevations in epinephrine, no significant changes in heart rate or mean arterial pressure were noted. Plain lidocaine provided unsatisfactory levels of hemostasis and/or anesthesia during periodontal surgery. This study documents acute elevations in plasma epinephrine levels following local dental anesthesia for periodontal surgery. These elevations in plasma epinephrine failed to produce a significant cardiovascular response in a group of stable cardiovascular disease patients. This suggests that the cardiac effects of local anesthetics containing epinephrine are small and that they can be safely used in stable cardiovascular disease patients.

Defects in neutrophil or polymorphonuclear leukocyte (PMNL) chemotaxis have been observed in a number of clinical conditions, including Down's syndrome and insulin-dependent diabetes mellitus (IDDM), which tend to be associated with severe forms of periodontal disease. In addition, impaired PMNL chemotaxis is frequently detected in individuals with localized juvenile periodontitis (LJP). The ability to monitor PMNL function in vivo at the gingival sulcus should therefore be useful as a diagnostic test. In this regard, we developed a technique which measures the response of PMNLs to a chemotactic agent, e.g., casein and N-formylmethionylleucylphenylalanine (N-FMLP) placed directly into gingival crevices. The development of the technique and its relationship to in vitro assays of chemotaxis are discussed, and data obtained from tests of the assay on control and streptozotocin-induced diabetic rats and human subjects with various periodontal diseases and IDDM are presented. As compared with healthy subjects and control animals, atypical (double peak) and reduced crevicular PMNL response patterns were observed during oral and systemic diseases. This suggests that the in vivo assay with appropriate modifications can be used diagnostically to assess PMNL migratory dysfunction and to identify individuals who may be susceptible to severe forms of periodontal disease.

An in vivo assay was recently developed to monitor the crevicular leucocyte response to chemotactic agents, e.g., casein and N-formyl peptides. This method was used to monitor humans with little or no gingival disease (C group), gingivitis (G group), chronic periodontitis (CP group) and localized juvenile periodontitis (LJP group). Casein (0.2 microliters, 2 mg/ml) was placed into an isolated gingival crevice of each subject with a calibrated wire loop and the time recorded (t = 0). Leucocytes were counted in crevicular washes (10 microliters) 15 minutes later and every 5 minutes thereafter up to t = 50 minutes. This protocol was repeated for the crevice of an adjacent tooth except that the crevicular fluid flow response to the chemotactic challenge was monitored. The C, G and CP subjects showed a similar pattern of response to the chemoattractant with a single "peak" of leucocytes at approximately t = 25 minutes. However, the peak cell count was much greater in the G and CP groups than in the C group. LJPs showed an abnormal pattern with two leucocyte peaks, one at approximately 25 minutes and the other at 45 minutes. Both peaks tended to be higher than the single peak seen in Cs but were significantly lower than that in Gs or CPs, even at similar levels of inflammation. In addition, the peak leucocyte response (to casein) in LJPs did not increase with increasing leucocyte counts in the unchallenged (resting) crevice, whereas a positive relationship was seen in the other groups of subjects. These data suggest that this new assay may provide important diagnostic information on in vivo neutrophil migration in the gingival crevice and on susceptibility to periodontal disease.

Defects in neutrophil or polymorphonuclear leukocyte (PMNL) Chemotaxis have been observed in a number of clinical conditions, including Down's syndrome and insulindependent diabetes mellitus (IDDM), which tend to be associated with severe forms of periodontal disease. In addition, impaired PMNL Chemotaxis is frequently detected in individuals with localized juvenile periodontitis (LJP). The ability to monitor PMNL function in vivo at the gingival sulcus should therefore be useful as a diagnostic test. In this regard, we developed a technique which measures the response of PMNLs to a chemotactic agent, e.g., casein and N-formylmethionylleucylphenylalanine (N-FMLP) placed directly into gingival crevices. The development of the technique and its relationship to in vitro assays of Chemotaxis are discussed, and data obtained from tests of the assay on control and streptozotocin-induced diabetic rats and human subjects with various periodontal diseases and IDDM are presented. As compared with healthy subjects and control animals, atypical (double peak) and reduced crevicular PMNL response patterns were observed during oral and systemic diseases. This suggests that the in vivo assay with appropriate modifications can be used diagnostically to assess PMNL migratory dysfunction and to identify individuals who may be susceptible to severe forms of periodontal disease., (© 1985 American Academy of Periodontology.)

In the first section of this two-part report human peripheral blood leukocytes were tested for reactivity to extracts of sclera. Absence of scleral antigenicity is suggested by the results which showed that the leukocytes reacted similarly in sclera stimulated cultures and in the controls. The second part of the report discusses the clinical aspects of sclera allografts and provides guidelines for their clinical use. A case is presented where a sclera graft was in position for approximately a year. The tooth was removed with the attached graft and a histologic study made.