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.

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.

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-1β, Il-1RA, Il-6, Il-8, Il-17, b-FGF, G-CSF, GM-CSF, IFNɣ, MIP-1β, 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-1β, and TNF-α at zirconia implants and teeth. The levels of IL-1β 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-1β 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.

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.

Systemic Biomarkers in 2-Phase Antibiotic Periodontal Treatment: A Randomized Clinical Trial

Accumulating evidence suggests that periodontal infections may have an impact on systemic health. In patients with untreated periodontitis, very high values for several inflammatory markers in serum are expressed simultaneously. We investigated to what extent these peak values change after nonsurgical and surgical periodontal treatment, with adjunctive antibiotics administered during the first or the second treatment phase. In a single-center, randomized, placebo-controlled, and double-masked clinical trial, 80 patients with chronic or aggressive periodontitis were randomized into 2 treatment groups: group A, receiving systemic amoxicillin and metronidazole during the first, nonsurgical phase of periodontal therapy (phase 1), and group B, receiving the antibiotics during the second, surgical phase (phase 2). Serum samples were obtained at baseline (BL), 3 mo after phase 1 (M3), and 6 and 12 mo after phase 2 (M6, M12). Samples 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 mean +2 SD of measurements found in 40 periodontally healthy persons. Sixty-six patients showed a peak value of at least 1 analyte at BL. At M12, the number of these patients was only 36 (P = 0.0002). This decrease was stronger in group A (BL: 35, M12: 19, P = 0.0009) than in group B (BL: 31, M12: 17, P = 0.14). Twenty patients displayed peak values of at least 4 biomarkers at BL. The nonsurgical therapy delivered in the first phase reduced most of these peaks (group A, BL: 9, M3: 4, P = 0.17; group B, BL: 11, M3: 2, P = 0.01), irrespective of adjunctive antibiotics. The reductions obtained at M3 were maintained until M12 in both groups. Initial, nonsurgical periodontal therapy reduced the incidence of peak levels of inflammatory markers. Antibiotics and further surgical therapy did not enhance the effect (Clinicaltrials.gov NCT02197260).

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.

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.

[Efficient, minimally invasive periodontal therapy. An evidence based treatment concept]

A large number of reports indicate beneficial effects of systemic antibiotics for patients with periodontal diseases. Although these advantages are clear in general, the specific relationship of benefit and risk in various clinical situations remains a subject of debate. Uncertainties persist regarding the individual prescription and combination with other procedures. Since the early 1990s it has been pointed out that systemic antibiotics given in the context of non-surgical subgingival debridement may reduce the need for periodontal surgery. Recent studies confirm these findings especially with regard to the combination of amoxicillin and metronidazole. However, these antibiotics should not be viewed as a substitute for thorough debridement, or as a means to compensate for improper oral hygiene. In addition, current evidence does not provide evidence for the indiscriminate use of just any antibiotic in any periodontal patient. A treatment protocol implementing the recent evidence is shown. It is noteworthy to realize that chronic and aggressive periodontitis today can be treated successfully with simple and cost-effective means in most instances.

Systemic conditions and treatments as risks for implant therapy

PURPOSE

To evaluate whether systemic diseases with/without systemic medication increase the risk of implant failure and therefore diminish success and survival rates of dental implants.

MATERIALS AND METHODS

A MEDLINE search was undertaken to find human studies reporting implant survival in subjects treated with osseointegrated dental implants who were diagnosed with at least one of 12 systemic diseases.

RESULTS

For most conditions, no studies comparing patients with and without the condition in a controlled setting were found. For most systemic diseases there are only case reports or case series demonstrating that implant placement, integration, and function are possible in affected patients. For diabetes, heterogeneity of the material and the method of reporting data precluded a formal meta-analysis. No unequivocal tendency for subjects with diabetes to have higher failure rates emerged. The data from papers reporting on osteoporotic patients were also heterogeneous. The evidence for an association between osteoporosis and implant failure was low. Nevertheless, some reports now tend to focus on the medication used in osteoporotic patients, with oral bisphosphonates considered a potential risk factor for osteonecrosis of the jaws, rather than osteoporosis as a risk factor for implant success and survival on its own.

CONCLUSIONS

The level of evidence indicative of absolute and relative contraindications for implant therapy due to systemic diseases is low. Studies comparing patients with and without the condition in a controlled setting are sparse. Especially for patients with manifest osteoporosis under an oral regime of bisphosphonates, prospective controlled studies are urgently needed.

Systemic diseases affecting osseointegration therapy

OBJECTIVES

To evaluate the impact of systemic diseases and their treatment on the success of osseointegration therapy.

MATERIAL AND METHODS

A search was made to find human studies including subjects treated with osseointegrated oral implants, with a diagnosis of 11 systemic diseases, and reporting at least implant survival.

RESULTS

For most conditions, no studies comparing patients with and without the condition in a controlled setting were found. The evidence to recommend implant therapy was low and consisted in presentations of some successfully treated cases. With regard to diabetes, three types of reports were found: eight case series of diabetic patients treated with implants, six cross-sectional, longitudinal or retrospective evaluations of groups of subjects treated with implants, including some diabetic patients, and one matched control retrospective chart survey. The heterogeneity of the material and the method of data reporting precluded a formal meta-analysis. No unequivocal tendency for subjects with diabetes to have higher failure rates emerged, but the largest of these studies indicated a significant increase in the relative risk of implant failure with diabetes. The data obtained from 17 papers reporting data from osteoporotic patients were also heterogeneous. The evidence for an association of osteoporosis and implant failure was low.

CONCLUSIONS

The level of evidence indicative of absolute and relative contraindications for implant therapy due to systemic diseases is low. Many conditions have been listed as potentially critical, but studies comparing patients with and without the condition in a controlled setting are sparse.