Quantification of titanium and zirconium elements in oral mucosa around healthy dental implants: a case-control pilot study.

OBJECTIVES: Metallic particles are detected in different sites of the oral cavity, mainly in patients with peri-implantitis lesions. The aim of this pilot study was to analyze the levels of titanium and zirconium elements in the oral mucosa around healthy implants and to investigate the impact of titanium exogenous contamination on the measurements. MATERIALS AND METHODS: Forty-one participants were included in this three-phase study. Two groups of subjects were defined according to presence of titanium or zirconia implants (n: 20) or without any implants nor metallic restorations (n:21). Thirteen patients (n: 5 with zirconia implant; n: 3 with titanium implants; n: 5 control group) took part to the first part designed to optimize and validate the method of detecting titanium (Ti) and zirconium (Zr) elements in the oral mucosa and gingival tissues by the Inductively Coupled Plasma Mass Spectrometry (ICPMS). The second phase compared the levels of Ti and Zr concentrations in patients with implants (n: 12) and without implants (n: 6) who were controlled for their intake of titanium dioxide (TiO2). The last step included ten control subjects without any metallic devices to measure the concentration of Ti and Zr before and after having candies containing TiO2. RESULTS: In the first phase, concentrations of Ti and Zr were below the limit of detection (LOD) in most cases, 0.18 µg/L and 0.07 µg/L respectively. In the titanium group, two out of three subjects displayed concentrations above the LOD, 0.21 µg/L and 0.66 µg/L. Zr element was only found in patients with zirconia implants. After controlling the intake of TiO2, all concentrations of Ti and Zr were below the limit of quantification (LOQ). Moreover, in patients with no implants, the Ti concentration in gingiva cells was superior for 75% of the samples after having a TiO2 diet. CONCLUSIONS: Zirconium was only found in patients with zirconia implants, whereas titanium was detected in all groups even in subjects with no titanium implants. Zirconium and titanium elements were not detected in patients who were controlled for their intake of food and their use of toothpaste irrespective of the presence of implants or not. For 70% of the patients, the titanium detection was directly influenced by the intake of TiO2 contained candies. CLINICAL RELEVANCE: When analyzing titanium particles, it is necessary to pay attention to the risk of contamination bias brought by external products. When this parameter was controlled, no titanium particles were detected around clinically healthy implants.

Cost savings in the Swiss healthcare system resulting from professional periodontal care.

More than 740 million people worldwide are affected by periodontal disease and are at higher risk of secondary damage such as cardiovascular disease and type 2 diabetes, which place a considerable financial burden on healthcare systems. The aim of this study was to use a computer simulation to estimate the direct and indirect costs of prevention and treatment of gingivitis, periodontitis and related secondary damage in the Swiss population, paid both out of pocket (OOP) and from social welfare (SW). For three different scenarios, iterations with 200,000 simulated individuals over their assumed life span of 35 to 100 years corresponded to a period of four months in which an individual could move from one periodontal condition to the next, each associated with presumed direct and indirect treatment costs. Appropriate diagnosis and adherence to professional periodontal care had a strong benefit saving up to CHF 5.94 billion OOP and CHF 1.03 billion SW costs for the current Swiss population. Considering direct and indirect health care costs, the total expected costs for a 35-year-old individual until death were CHF 17'310 with minimal care and CHF 15'606 with optimal care, resulting in savings of CHF 1'704. In conclusion, early detection and appropriate treatment of periodontitis can help to reduce both overall costs of treating periodontitis and associated secondary damage, especially in the second half of life. These cost savings may further pay off on an individual level through regular supportive periodontal care, both for treatments paid out-of-pocket and those covered by social welfare.

Two-piece zirconia implants supporting all-ceramic crowns: Six-year results of a prospective cohort study.

OBJECTIVES: The aim of this prospective clinical trial was to present the 6-year outcomes of a two-piece yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) implant system in partially edentulous patients. MATERIAL AND METHODS: Forty-nine two-piece zirconia implants were placed in 32 patients systemically healthy. Zirconia abutments were connected with adhesive resin cement. Single-unit full-ceramic crowns were cemented. The cases have been followed for an average of 82.2 ± 5.86 months after loading (range 74.93-92.26 months). RESULTS: 24 participants with 39 implants were available for examination 6 years after loading. The cumulative implant survival rate was 83%. On an implant level, the cumulative mechanical complication rate was 17.5%, the cumulative technical complication rate was 13%, and the biological complication rate was 8%. After 6 years, subjects reported good satisfaction with the treatment: 3.7 ± 4.4 on a visual analog scale (VAS) from 0 to 100 mm. CONCLUSIONS: Within the limitations of this prospective case series study, two-piece zirconia implants could offer an alternative for treatment of single edentulous spaces in the posterior region. The major complication on the long term of this pioneering system was the abutment fracture; however, due to the versatility of a two-piece implant system, replacement of the broken parts was possible.

Group 4 ITI Consensus Report: Risks and biologic complications associated with implant dentistry.

OBJECTIVES: The aim of Working Group 4 was to address topics related to biologic risks and complications associated with implant dentistry. Focused questions on (a) diagnosis of peri-implantitis, (b) complications associated with implants in augmented sites, (c) outcomes following treatment of peri-implantitis, and (d) implant therapy in geriatric patients and/or patients with systemic diseases were addressed. MATERIALS AND METHODS: Four systematic reviews formed the basis for discussion in Group 4. Participants developed statements and recommendations determined by group consensus based on the findings of the systematic reviews. These were then presented and accepted following further discussion and modifications as required by the plenary. RESULTS: Bleeding on probing (BOP) alone is insufficient for the diagnosis of peri-implantitis. The positive predictive value of BOP alone for the diagnosis of peri-implantitis varies and is dependent on the prevalence of peri-implantitis within the population. For patients with implants in augmented sites, the prevalence of peri-implantitis and implant loss is low over the medium to long term. Peri-implantitis treatment protocols which include individualized supportive care result in high survival of implants after 5 years with about three-quarters of implants still present. Advanced age alone is not a contraindication for implant therapy. Implant placement in patients with cancer receiving high-dose antiresorptive therapy is contraindicated due to the associated high risk for complications. CONCLUSIONS: Diagnosis of peri-implantitis requires the presence of BOP as well as progressive bone loss. Prevalence of peri-implantitis for implants in augmented sites is low. Peri-implantitis treatment should be followed by individualized supportive care. Implant therapy for geriatric patients is not contraindicated; however, comorbidities and autonomy should be considered.

The diagnosis of peri-implantitis: A systematic review on the predictive value of bleeding on probing.

OBJECTIVES: Bleeding on gentle probing (BOP) is the key parameter to the diagnosis of mucositis, while changes in crestal bone levels, along with clinical signs of inflammation, are required for the diagnosis of peri-implantitis. This systematic review and meta-analysis focused on the evaluation of BOP as a predictive measure for peri-implantitis. MATERIALS AND METHODS: An electronic search was performed through Medline and EMBASE databases, followed by a hand search through previous reviews and reference lists. Screening, study selection, data extraction and evaluation of publication bias were conducted by two independent examiners. Clinical studies reporting on the prevalence of peri-implantitis, BOP and/or suppuration (SUP) after more than 1 year of functional loading were selected. Meta-analyses were conducted to combine the proportions of peri-implantitis among BOP- and/or SUP-positive subjects and implants across studies. Subgroups were created and compared to investigate potential sources of heterogeneity. RESULTS: Thirty-one studies were selected for analysis. Inconsistent definitions of peri-implantitis were reported across the studies. Twenty-nine studies reported data on implant-level and twenty publications reported on subject-level. The combined proportion of peri-implantitis was 24.1% (95% CI 19.3-29.7) in BOP-positive implants and 33.8% (95% CI 26.7-41.6) for BOP-positive cases. However, the degree of variability among studies was high; the prediction intervals were 10.3-69.3 and 6.9-57.8, respectively. Evidence of asymmetry or publication bias could not be statistically detected. Short observation periods were significantly associated with lower proportions of peri-implantitis among BOP-positive implants. CONCLUSIONS: For BOP-positive implants, there was a 24.1% chance to be diagnosed with peri-implantitis; while for BOP-positive patients, there was a 33.8% probability to be diagnosed with peri-implantitis. This probability varied across study populations. Clinicians should be aware of the considerable false-positive rate of BOP to diagnose peri-implantitis.

What is the impact of titanium particles and biocorrosion on implant survival and complications? A critical review.

OBJECTIVES: To compile the current evidence regarding the association between the release of titanium particles and biologic complications of dental implants. MATERIAL AND METHODS: This is a critical review. We searched the literature using the terms "corrosion," "allergy," "hypersensitivity," or "particles" together with "titanium," "Ti," "TiO2. " The bibliographies of identified publications and previously published review articles were scanned to find additional related articles. We included clinical studies, in vivo and in vitro experiments. RESULTS: Titanium particles and degradation products of titanium have been detected in oral and nonoral tissues. Particles are released from surfaces of dental implants because of material degradation in a process called tribocorrosion. It involves mechanical wear and environmental factors, notably contact to chemical agents and interaction with substances produced by adherent biofilm and inflammatory cells. In vitro, titanium particles can interfere with cell function and promote inflammation. A temporal association between exposure to titanium and occurrence of tissue reactions suggested hypersensitivity in a limited number of cases. However, there is poor specificity as the observed reactions could be initiated by other factors associated with the placement of implants. Titanium particles are commonly detected in healthy and diseased peri-implant mucosa alike, at low levels even in gingiva of individuals without titanium implants. Rather than being the trigger of disease, higher concentrations of titanium in peri-implantitis lesions could be the consequence of the presence of biofilms and inflammation. CONCLUSION: There is an association between biocorrosion, presence of titanium particles, and biological implant complications, but there is insufficient evidence to prove a unidirectional causal relationship.

Acute necrotising gingivitis in young children from villages with and without noma in Niger and its association with sociodemographic factors, nutritional status and oral hygiene practices: results of a population-based survey.

BACKGROUND: Previous studies have suggested that acute necrotising gingivitis precedes noma disease and that noma clusters in some villages in certain regions of low- and middle-income countries. We sought to assess the prevalence of gingivitis with bleeding in young children from villages with or without a history of noma and to analyse epidemiological differences related to sociodemographic characteristics, nutritional status and oral hygiene practices. METHODS: We conducted a cross-sectional study in 440 children aged between 2 and 6 years from four villages in the Zinder region of southeast Niger in Africa. In two villages, cases of noma have repeatedly been detected; in the other two, noma has never been identified. We randomly selected 110 participants from each village. RESULTS: The prevalence of acute necrotising gingivitis was significantly higher in the noma villages compared with the non-noma villages (6.8% vs 0.9%; p=0.001). We found differences between the four villages regarding socioeconomic factors, stunting, undernourishment and oral hygiene practices. The type of oral hygiene procedures influenced the amount of dental plaque and gingival inflammation. Children using sand, coal or other abrasive products instead of a toothbrush had a significantly increased likelihood to be diagnosed with acute necrotising gingivitis (p=0.041). CONCLUSIONS: Our data suggest that efforts to prevent noma should focus on populations with a high prevalence of acute necrotising gingivitis and include nutritional support and attempts to introduce safe and efficient oral hygiene practices to improve gingival health.

Microbiologic Response to Periodontal Therapy and Multivariable Prediction of Clinical Outcome.

BACKGROUND: This study assesses the microbiologic effects of a two-phase antimicrobial periodontal therapy and tested microbiologic, clinical, and biologic markers as prognostic indicators for clinical success. METHODS: Eighty patients with chronic or aggressive periodontitis received periodontal treatment supplemented with 375 mg amoxicillin plus 500 mg metronidazole, three times daily for 7 days. In group A, antibiotics were given during the first non-surgical phase (T1); in group B, antibiotics were given during the second surgical phase (T2). Six microorganisms, group assignment, demographic and clinical variables, peak values of 15 cytokines, and nine acute-phase proteins in serum were evaluated as potential predictors of at least one site with probing depth (PD) >4 mm and bleeding on probing (BOP) at 12 months post-therapy. RESULTS: T1 decreased the counts of Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia (Pi), and Treponema denticola significantly more in group A than group B. Aggregatibacter actinomycetemcomitans and Parvimonas micra (Pm) showed a significant decrease only if the treatment was supplemented with antibiotics, i.e., T1 in group A, or T2 in group B. After T2, differences between groups were no longer significant. A multivariable model including four parameters revealed a predictive value of Pm (odds ratio [OR] = 4.38, P = 0.02) and Pi (OR = 3.44, P = 0.049) and yielded moderate accuracy for predicting the treatment outcome (area under the curve = 0.72). Host-derived factors and treatment sequence were not significantly associated with the outcome. CONCLUSIONS: Long-term microbiologic outcomes of periodontal therapy with adjunctive antibiotics either in T1 or T2 were similar. Detection of Pm before therapy was a predictor for persistence of sites with PD >4 mm and BOP at 12 months post-treatment.

Zirconia dental implants: where are we now, and where are we heading?

Despite decades of titanium as the gold standard in oral implantology, the search for alternatives has been growing. High esthetic standards and increasing incidence of titanium allergies, along with a rising demand for metal-free reconstructions, have led to the proposal of ceramics as potential surrogates. Following numerous experimental studies, zirconium dioxide (zirconia) has earned its place as a potential substitute for titanium in implantology. Yet, despite zirconia's excellent biocompatibility and tissue integration, low affinity to plaque and favorable biomechanical properties, early failures were significantly higher for zirconia implants than for titanium implants. Technical failure as a result of fracture of the material is also a major concern. So far, zirconia implants have been mainly manufactured as one-piece implant systems because of the material's limitations. Nevertheless, various two-piece systems have been progressively emerging with promising results. Screw-retained abutments are desirable but present a major technical challenge. Innovation and technical advances will undoubtedly lead to further improvement in the reliability and strength of zirconia implants, allowing for novel designs, connections and reconstructions. Additional clinical studies are required to identify all relevant technical and biological factors affecting implant success and patients' satisfaction. However, the evidence for a final verdict is, at present, still incomplete.

A systematic review of the clinical survival of zirconia implants.

OBJECTIVES: The aim of this review was to evaluate the clinical success and survival rates of zirconia ceramic implants after at least 1 year of function and to assess if there is sufficient evidence to justify using them as alternatives to titanium implants. MATERIALS AND METHODS: An electronic search in MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Clinical Trials (CENTRAL) databases was performed in April 2015 by two independent examiners to retrieve clinical studies focusing on the survival rate of zirconia implants after at least 1 year of function. Implant survival was estimated using the overall proportion reported in the studies with a Clopper-Pearson 95 % confidence interval (random effect model with a Der-Simonian Laird estimate). RESULTS: Fourteen articles were selected out of the 1519 titles initially screened. The overall survival rate of zirconia one- and two-piece implants was calculated at 92 % (95 % CI 87-95) after 1 year of function. The survival of implants at 1 year for the selected studies revealed considerable heterogeneity. CONCLUSIONS: In spite of the unavailability of sufficient long-term evidence to justify using zirconia oral implants, zirconia ceramics could potentially be the alternative to titanium for a non-metallic implant solution. However, further clinical studies are required to establish long-term results, and to determine the risk of technical and biological complications. Additional randomized controlled clinical trials examining two-piece zirconia implant systems are also required to assess their survival and success rates in comparison with titanium as well as one-piece zirconia implants. CLINICAL RELEVANCE: Zirconia implants provide a potential alternative to titanium ones. However, clinicians must be aware of the lack of knowledge regarding long-term outcomes and specific reasons for failure.

Pro-inflammatory cytokines at zirconia implants and teeth. A cross-sectional assessment.

OBJECTIVES: The aim of this study was to compare the expression of host-derived markers in peri-implant/gingival crevicular fluid (PCF/GCF) and clinical conditions at ceramic implants and contralateral natural teeth. As a secondary objective, we compared zirconia implants with titanium implants. METHODS: One zirconia implant (ZERAMEX® Implant System) and one contralateral natural tooth were examined in 36 systemically healthy subjects (21 males, 15 females, mean age 58). The levels of Il-1ß, Il-1RA, Il-6, Il-8, Il-17, b-FGF, G-CSF, GM-CSF, IFNÉ£, MIP-1ß, TNF-α, and VEGF were assessed in PCF/GCF using the Bio-Plex 200 Suspension Array System. The plaque index (PI), gingival index (GI), probing depth (PD), and bleeding on probing (BOP) were assessed at six sites around each implant or tooth. Titanium implants were also assessed when present (n = 9). RESULTS: The zirconia implants were examined after a loading period of at least 1.2 years (average 2.2 years). The mean PI was significantly lower at zirconia implants compared to teeth (p = 0.003), while the mean GI, PD, and BOP were significantly higher (p < 0.001). A correlation was found in the expression of Il-1RA, Il-8, G-CSF, MIP-1ß, and TNF-α at zirconia implants and teeth. The levels of IL-1ß and TNF-α were significantly higher at zirconia implants than at teeth. No significant differences were found between zirconia and titanium implants. A correlation was found between the levels of IL-1RA, IL-8, GM-CSF, and MIP-1ß at zirconia and titanium implants. CONCLUSIONS: The correlation in the expression of five biomarkers at zirconia implants and teeth, and of four biomarkers at zirconia and titanium implants, is compatible with the existence of a patient-specific inflammatory response pattern. Higher mean GI, PD, and BOP around implants suggests that the peri-implant mucosa may be mechanically more fragile than the gingiva. CLINICAL RELEVANCE: Similar expression of selected biomarkers at zirconia implants and teeth and at zirconia and titanium implants reflects existence of patient-specific inflammatory response patterns.

Effect of Periodontal Therapy With Amoxicillin-Metronidazole on Pharyngeal Carriage of Penicillin- and Erythromycin-Resistant Viridans Streptococci.

BACKGROUND: Previous studies have focused on antibiotic resistance of Gram-negative bacteria before and after periodontal therapy. The purpose of this analysis is to assess changes in resistance patterns of the commensal Gram-positive microbiota. The viridans group streptococci (VGS) have been suggested to serve as reservoirs of resistance genes for more pathogenic streptococci and may be implicated in some non-oral infections. METHODS: In this randomized clinical trial, 80 patients with periodontitis are distributed randomly into two groups. In group A, patients received 375 mg amoxicillin and 500 mg metronidazole three times per day for 7 days during the non-surgical treatment phase (T1). In group B, the antibiotics were administered during the surgical phase (T2). Resistance of VGS to penicillin and erythromycin was determined by the epsilometer test. RESULTS: At baseline, VGS from 12.5% (group A) and 11.8% (group B) of patients had a minimum inhibitory concentration (MIC) >2 µg/mL to penicillin. Three months after T1, VGS from 15.6% and 16.7% of patients had an MIC >2 µg/mL, respectively. Six months after T2 VGS from 5.9% and 5.9% and 12 months after T2 VGS from 6.1% and 6.3% patients had an MIC >2 µg/mL. There was no effect of therapy with antibiotics, administered either in T1 or T2, on the carriage of penicillin-resistant VGS. Erythromycin resistance was high at baseline and remained unchanged throughout the study. MICs for penicillin and erythromycin were correlated (P <0.05). CONCLUSION: Amoxicillin plus metronidazole did not significantly affect the resistance pattern of the VGS to penicillin or erythromycin.

Differential benefits of amoxicillin-metronidazole in different phases of periodontal therapy in a randomized controlled crossover clinical trial.

BACKGROUND: The specific advantage of administering systemic antibiotics during initial, non-surgical therapy or in the context of periodontal surgery is unclear. This study assesses the differential outcomes of periodontal therapy supplemented with amoxicillin-metronidazole during either the non-surgical or the surgical treatment phase. METHODS: This is a single-center, randomized placebo-controlled crossover clinical trial with a 1-year follow-up. Eighty participants with Aggregatibacter actinomycetemcomitans-associated moderate to advanced periodontitis were randomized into two treatment groups: group A, antibiotics (500 mg metronidazole plus 375 mg amoxicillin three times per day for 7 days) during the first, non-surgical phase of periodontal therapy (T1) and placebo during the second, surgical phase (T2); and group B, placebo during T1 and antibiotics during T2. The number of sites with probing depth (PD) >4 mm and bleeding on probing (BOP) per patient was the primary outcome. RESULTS: A total of 11,212 sites were clinically monitored on 1,870 teeth. T1 with antibiotics decreased the number of sites with PD >4 mm and BOP per patient significantly more than without (group A: from 34.5 to 5.7, 84%; group B: from 28.7 to 8.7, 70%; P <0.01). Twenty patients treated with antibiotics, but only eight treated with placebo, achieved a 10-fold reduction of diseased sites (P = 0.007). Consequently, fewer patients of group A needed additional therapy, the mean number of surgical interventions was lower, and treatment time in T2 was shorter. Six months after T2, the mean number of residual pockets (group A: 2.8 ± 5.2; group B: 2.2 ± 5.0) was not significantly different and was sustained over 12 months in both groups. CONCLUSION: Giving the antibiotics during T1 or T2 yielded similar long-term outcomes, but antibiotics in T1 resolved the disease quicker and thus reduced the need for additional surgical intervention.

Two-piece zirconia implants supporting all-ceramic crowns: a prospective clinical study.

OBJECTIVES: The aim of this prospective clinical study is to evaluate the safety and efficacy of a new all-ceramic implant system to replace missing teeth in partially edentulous patients. MATERIAL AND METHODS: Thirty-two partially edentulous, systemically healthy patients were treated with 49 two-piece zirconia implants (ZERAMEX(®) T Implant System). Zirconia abutments were connected with adhesive resin cement. Single-unit full-ceramic crowns were cemented. The cases have been followed for 588 ± 174 days after loading (range 369-889 days). All patients have been re-evaluated 1 year after loading. RESULTS: The cumulative survival rate 1 year after loading was 87% implants. All failures were the result of aseptic loosening, and no implants were lost after the first year. The results of the other cases were good, and the patients were very satisfied. The cumulative soft tissue complication rate was 0%, the cumulative technical complication rate was 4% implants, the cumulative complication rate for bone loss >2 mm was 0%, and the cumulative esthetic complication rate was 0%. Including the data from 20 patients treated with an earlier version of the system, an over-all 2-year cumulative survival rate of 86% was calculated for a total of 76 two-piece zirconia implants supporting all-ceramic crowns in 52 patients. CONCLUSIONS: Replacement of single teeth in the posterior area was possible with this new full-ceramic implant system. Failures were due to aseptic loosening.

Effect of periodontal treatment on peak serum levels of inflammatory markers.

BACKGROUND AND OBJECTIVE: Some subjects with untreated periodontitis exhibit elevated levels of distinct inflammatory markers in serum. The aim of the study was to assess whether nonsurgical periodontal therapy changes the levels of these markers and lowers these peaks. METHODS: Forty periodontally diseased subjects received nonsurgical periodontal therapy (full-mouth scaling and root planing within 48 h) with either adjunctive systemic amoxicillin and metronidazole (n = 19) or placebo (n = 21). Serum samples, obtained at baseline (BL) and 3 months after treatment (M3), were evaluated for 15 cytokines and 9 acute-phase proteins using the Bio-Plex bead array multianalyte detection system. For each analyte, peak values were defined as greater than the mean + 2 standard deviations (SD) of measurements found in 40 periodontally healthy persons. Proportions were compared using Fisher's exact test. RESULTS: At M3, a significantly better primary clinical outcome (persisting pockets of >4 mm with bleeding on probing) was obtained in patients treated with scaling and root planing plus antibiotics compared to those receiving placebo (3.3 ± 5.1 vs. 6.8 ± 7.8 pockets per patient, p < 0.05). The levels of cytokines and acute-phase proteins of periodontitis patients were usually below the mean + 2 SD threshold of healthy persons. However, values above threshold were found in some individuals. Eleven patients showed a peak value of one analyte, and seven patients showed two peaks. In the remaining 12 patients, between three and ten analytes showed peak values. Therapy greatly reduced the number of subjects with four or more peaks (BL, 11 subjects; M3, 1 subject, p = 0.003). With regards to the reduction of peaks, no specific benefit of adjunctive antibiotics could be seen. CONCLUSION: Subjects with untreated periodontitis may show high peaks for several inflammatory markers in serum simultaneously. Nonsurgical periodontal treatment with or without antibiotics reduced most of these peak levels.

Are there specific benefits of amoxicillin plus metronidazole in Aggregatibacter actinomycetemcomitans-associated periodontitis? Double-masked, randomized clinical trial of efficacy and safety.

BACKGROUND: It has been suggested that prescription of amoxicillin plus metronidazole in the context of periodontal therapy should be limited to patients with specific microbiologic profiles, especially those testing positive for Aggregatibacter actinomycetemcomitans. The main purpose of this analysis is to determine if patients positive for A. actinomycetemcomitans with moderate to advanced periodontitis benefit specifically from amoxicillin plus metronidazole given as an adjunct to full-mouth scaling and root planing. METHODS: This is a double-masked, placebo-controlled, randomized longitudinal study including 41 participants who were positive for A. actinomycetemcomitans and 41 participants who were negative for A. actinomycetemcomitans. All 82 patients received full-mouth periodontal debridement performed within 48 hours. Patients then received either systemic antibiotics (375 mg amoxicillin and 500 mg metronidazole, three times daily) or placebo for 7 days. The primary outcome variable was persistence of sites with a probing depth (PD) >4 mm and bleeding on probing (BOP) at the 3-month reevaluation. Using multilevel logistic regression, the effect of the antibiotics was analyzed according to the following factors (interaction effect): A. actinomycetemcomitans-positive or -negative at baseline, sex, age, smoking, tooth being a molar, and interdental location. RESULTS: At reevaluation, participants in the test group had significantly fewer sites with a persisting PD >4 mm and BOP than control patients (P <0.01). Being A. actinomycetemcomitans-positive or -negative did not change the effect of the antibiotics. Patients benefited from the antibiotics irrespective of sex, age, or smoking status. Molars benefited significantly more from the antibiotics than non-molars (P for interaction effect = 0.03). CONCLUSIONS: Patients who were positive for A. actinomycetemcomitans had no specific benefit from amoxicillin plus metronidazole. Sites on molars benefited significantly more from the antibiotics than non-molar sites.

The epidemiology of peri-implantitis.

AIM: To review the literature on the prevalence and incidence of peri-implantitis. METHODS: Out of 322 potentially relevant publications we identified 29 articles concerning 23 studies, with information on the presence of signs of peri-implantitis in populations of at least 20 cases. RESULTS AND CONCLUSIONS: All studies provided data from convenience samples, typically from patients who were treated in a clinical center during a certain period, and most data were cross-sectional or collected retrospectively. Based on the reviewed papers one may state that the prevalence of peri-implantitis seems to be in the order of 10% implants and 20% patients during 5-10 years after implant placement but the individual reported figures are rather variable, not easily comparable and not suitable for meta-analysis. Factors that should be considered to affect prevalence figures are the disease definition, the differential diagnosis, the chosen thresholds for probing depths and bone loss, differences in treatment methods and aftercare of patients, and dissimilarities in the composition of study populations. Smoking and a history of periodontitis have been associated with a higher prevalence of peri-implantitis.

Microbial profiles of patients seeking treatment for periodontitis. Influence of origin, smoking and age?

PURPOSE: We assessed the potential influence of the origin, the smoking status and the age on subgingival microbial profiles of subjects seeking periodontal care in Switzerland today. MATERIAL AND METHODS: Subgingival samples were obtained from 182 subjects originating from 44 countries (56 native Swiss, 64 other European, 43 African, 19 others), seeking periodontal treatment at the School of Dental Medicine at the University of Geneva. Four periodontal microorganisms were quantified by direct hybridization with specific RNA probes. RESULTS: Tannerella forsythia and Treponema denticola were ubiquitous (95.6%, 93.9%), and Porphyromonas gingivalis was frequently detected (89%). Counts correlated with the size of the microbial sample (total load). Aggregatibacter actinomycetemcomitans was detected in only 70 (38.4%) subjects. Counts were highly variable and unrelated to total load. Subjects less than 46.8 years old (median age) had a higher risk to be positive than older subjects. Detection frequencies and counts of all four organisms were unrelated to the origin or the smoking status. CONCLUSIONS: Based on a clinical diagnosis of untreated periodontitis, positive outcomes of tests for T. forsythia, T. denticola and P. gingivalis could be predicted with high confidence irrespective of a patient;'s origin, smoking status or age. Detection of A. actinomycetemcomitans was less frequent and depended on the age of the subject.

Effect of photodynamic therapy, diode laser, and deep scaling on cytokine and acute-phase protein levels in gingival crevicular fluid of residual periodontal pockets.

BACKGROUND: There is an ongoing controversy on the benefits of treatment protocols, including dental lasers and photodynamic therapy (PDT). The purpose of this study is to compare the local biologic effects of PDT, diode soft laser (DSL) therapy, and conventional deep scaling and root planing (SRP) in residual pockets. METHODS: Thirty-two individuals were included based on a history of previous treatment for periodontitis and the persistence of sites with probing depths >4 mm and bleeding on probing. Residual pockets were debrided with an ultrasonic device and then randomly assigned either to PDT, DSL, or SRP. Gingival crevicular fluid was collected before treatment, after 14 days, and at 2 and 6 months. Levels of 13 cytokines and nine acute-phase proteins were measured using a bead-based multiplexing analysis system. RESULTS: Treatment with PDT, DSL, or SRP led to significant changes in several cytokines and acute-phase proteins: Compared with baseline, levels of interleukin-17, basic fibroblast growth factor, granulocyte colony-stimulating factor, granulocyte macrophage colony-stimulating factor, and macrophage inflammatory protein 1-α were lower 14 days and 2 months after treatment. Except for granulocyte colony-stimulating factor, these differences remained significant throughout the observation period. The levels of five acute-phase proteins (α-2 macroglobulin, haptoglobin, serum amyloid P, procalcitonin, and tissue plasminogen activator) were significantly higher at 6 months than at baseline. No significant differences were observed among the three treatment modalities at any time point for any biochemical parameter. CONCLUSIONS: Levels of several cytokines and acute-phase proteins significantly changed after treatment regardless of treatment modality. There was no evidence for a specific DSL- or PDT-enhanced expression of inflammatory mediators.