Relationships between varied clinical parameters of periodontium and acute myocardial infarction



Pobieranie 160.07 Kb.
Strona1/3
Data07.05.2016
Rozmiar160.07 Kb.
  1   2   3
Relationships between varied clinical parameters of periodontium and acute myocardial infarction.
Zależności pomiędzy różnymi parametrami klinicznymi przyzębia a występowaniem zawału mięśnia sercowego

Mariusz Bochniak DDS, PhD1 , Jadwiga Sadlak-Nowicka DDS, PhD1, Andrzej Rynkiewicz MD, PhD2 , Aida Kusiak DDS, PhD1


1. Department of Periodontology and Oral Mucosa Diseases,

Medical University of Gdańsk, Poland

Head: A.Kusiak DDS, PhD


  1. First Department of Cardiology,

Medical University of Gdańsk, Poland

Head: Prof. A.Rynkiewicz MD, PhD




Corresponding address:

Mariusz Bochniak DDS, PhD

Department of Periodontology and Oral Mucosa Diseases

Medical University of Gdańsk

Debowa 1A Str.

80-204 Gdańsk

Poland
e-mail: rstep@amg.gda.pl

fax: +48 58 3492178

Zależności pomiędzy różnymi parametrami klinicznymi przyzębia a występowaniem zawału mięśnia sercowego.
Relationships between varied clinical parameters of periodontium and acute myocardial infarction.
dr n. med. Mariusz Bochniak1 , prof. dr. hab. Jadwiga Sadlak-Nowicka1, prof. dr hab.Andrzej Rynkiewicz2 , dr hab. n. med. Aida Kusiak1


  1. Katedra i Zakład Periodontologii i Chorób Błony Śluzowej Jamy Ustnej,

Gdański Uniwersytet Medyczny

Kierownik: dr hab. n. med. A.Kusiak



  1. 1 Katedra i Klinika Kardiologii, Gdański Uniwersytet Medyczny

Kierownik: prof. dr hab. A. Rynkiewicz

Adres do korespondencji:

dr n.med. Mariusz Bochniak

Katedra i Zakład Periodontologii i Chorób Błony Śluzowej Jamy Ustnej GUMed

ul.Debowa 1A

80-204 Gdańsk
e-mail: rstep@amg.gda.pl

fax: +48 58 3492178



Abstract
BACKGROUND: The data published in recent years indicate periodontitis as one of potential risk factors for myocardial infarction (MI). Comparison of results obtained by authors is difficult due to non-homogenous parameters used in periodontal examination. A new Periodontal Index of Risk of Infectiousness (PIRI) was proposed to reliably assess the individual influence of periodontal foci on the systemic health

OBJECTIVES: An attempt at assessing the correlation of varied clinical periodontal parameters, including PIRI, with the risk of MI.

MATERIAL AND METHODS: The study encompassed 86 individuals with MI, aged 61.21 ± 7.89 (group 1), and 84 persons with stable coronary heart disease, aged 62.15 ± 7.73 (group 2). Clinical examinations of periodontium, using indices: API, mSBI, PPD, CAL, CPITN, PIRI were performed. Regression adjusted for confounding factors was used in statistic analysis.

RESULTS: A significantly higher mean values of mSBI, PPD, CAL and PIRI were observed in group 1. In multivariable analysis calculated OR for parameter PIRI as MI risk factor was significant (12.92), however with wide 95% confidence interval 1.06-452.7.

CONCLUSIONS: Among used periodontal variables mean value of PIRI index was most highly associated with presence of MI. In case of confirmation this findings in large research material, PIRI may become useful in the prophylaxis aspect for screening potential influence of periodontitis on cardiovascular system. It can also indicate the therapeutic direction towards quick reduction of such risk.

.
Keywords : periodontal disease, myocardial infarction, PIRI index

Streszczenie

WSTĘP: Doniesienia naukowe ostatnich lat wskazują na periodontitis jako potencjalny czynnik ryzyka zawału serca (ZS). Porównania wyników badań wielu autorów są trudne z powodu niejednorodnej metodologii badań – różnych parametrów używanych do oceny stanu przyzębia. Nowy wskaźnik – periodontologiczny wskaźnik ryzyka zakaźności (PIRI) został zaproponowany dla wiarygodnej oceny wpływu przyzębnych ognisk zakażenia na zdrowie ogólne człowieka.

CEL PRACY: próba oceny korelacji różnych parametrów periodontologicznych, włączając wskaźnik PIRI, z występowaniem zawału mięśnia sercowego.

MATERIAŁ I METODY: Badanie objęło 86 osób po ZS, średnia wieku 61.21 ± 7.89 (grupa 1), oraz 84 osoby ze stabilną chorobą niedokrwienną serca, średnia wieku 62.15 ± 7.73 (grupa 2). Wykonano kliniczne badanie przyzębia z użyciem wskaźników: API, mSBI, PPD, CAL, CPITN, PIRI. W analizie statystycznej użyto wieloczynnikowej regresji logistycznej z uwzględnieniem ogólnie uznanych czynników ryzyka ZS.

WYNIKI: Zaobserwowano istotnie statystycznie wyższe średnie wartości mSBI, PPD, CAL i PIRI u pacjentów z grupy 1. W analizie wieloczynnikowej wartość wskaźnika PIRI była statystycznie skorelowana z występowaniem ZS z ilorazem szans 12.92, jednakże z szerokim przedziałem 95% ufności 1.06-452.7.

WNIOSKI: Spośród parametrów oceniających stan przyzębia wskaźnik PIRI był najsilniej skorelowany z występowaniem ZS. W przypadku potwierdzenia tej obserwacji na większym materiale klinicznym, PIRI może okazać się przydatny w aspekcie profilaktycznym do przesiewowej oceny ryzyka wpływu stanu przyzębia na układ krążenia i wskazywać kierunek terapeutyczny zmierzający do szybkiego zredukowania tego ryzyka.
Słowa kluczowe: zapalenie przyzębia, zawał mięśnia sercowego, wskaźnik PIRI

Relationships between varied clinical parameters of periodontium and acute myocardial infarction.



Abstract

BACKGROUND: The data published in recent years indicate periodontitis as one of potential risk factors for myocardial infarction (MI). Comparison of results obtained by authors is difficult due to non-homogenous parameters used in periodontal examination. A new Periodontal Index of Risk of Infectiousness (PIRI) was proposed to reliably assess the individual influence of periodontal foci on the systemic health

OBJECTIVES: An attempt at assessing the correlation of varied clinical periodontal parameters, including PIRI, with the risk of MI.

MATERIAL AND METHODS: The study encompassed 86 individuals with MI, aged 61.21 ± 7.89 (group 1), and 84 persons with stable coronary heart disease, aged 62.15 ± 7.73 (group 2). Clinical examinations of periodontium, using indices: API, mSBI, PPD, CAL, CPITN, PIRI were performed. Regression adjusted for confounding factors was used in statistic analysis.

RESULTS: A significantly higher mean values of mSBI, PPD, CAL and PIRI were observed in group 1. In multivariable analysis calculated OR for parameter PIRI as MI risk factor was significant (12.92), however with wide 95% confidence interval 1.06-452.7.

CONCLUSIONS: Among used periodontal variables mean value of PIRI index was most highly associated with presence of MI. In case of confirmation this findings in large research material, PIRI may become useful in the prophylaxis aspect for screening potential influence of periodontitis on cardiovascular system. It can also indicate the therapeutic direction towards quick reduction of such risk.

Keywords : periodontal disease, myocardial infarction, PIRI index

Introduction. The interdependences between the health of the oral cavity and the health of the whole organism have been a subject of medical interest since the very beginning of medicine. Contemporary studies of the connection of periodontal diseases with systemic disorders and their mutual cause-effect relationships are one of the main areas of research in periodontology. In order to stress the independence and importance of this trend it was called ‘periodontal medicine’.

In the last years, special attention was drawn to the correlation between periodontitis and cardiovascular diseases, in particular coronary heart disease (CHD) and acute coronary events, including myocardial infarction (MI). First epidemiological research indicating the possibility of such relationship, was carried out in Finland in 1989.1 It concluded, that the condition of periodontium was significantly worse in patients suffering from myocardial infarction compared to the control group. Statistical analysis proved that the correlation was independent of the other known risk factors for MI.

Results of research carried out in following years corroborated these reports 2,3, even though there also appeared theses negating such correlation.4 Some reports indicated highest correlations in younger men subpopulation.5 Results negating gender-dependent differences were also published .6 In retrospective case-control studies the calculated odds ratio (OR) for acute coronary events for people with periodontitis ranged from 0.99 to 20. In prospective research (follow-up) the relative risk (RR) of death resulting from MI ranged from 1.00 to 2.67. These results convinced researchers to include periodontitis to risk factors for atherosclerosis and acute coronary events – in accordance with the infection – and inflammative etiopathogenetic theory of these diseases.3,7 It has been proved that periodontitis contributes to an increase in systemic inflammation. Elevated markers for systemic inflammation (for example C- reactive protein) are now considered recognized risk predictors of CHD and MI .8 This is most often postulated causative relationship between periodontal infection and atherosclerosis, CHD and MI. There are also other theories based on postulated direct colonization of atherosclerotic plaques with periodontal pathogens or role of immunoglobulin G .9

Direct comparison of various epidemiologic studies is made difficult by the fact, that the tested groups were not homogenous in their size, gender and age. Also the parameters used to assess the condition of periodontium varied. The greatest controversy comes from the choice of parameters for clinical assessment of periodontium tested in logistic regression models as potential risk factors for CHD and MI. In order to reliably assess the individual influence of pathological changed periodontium on the systemic health a new epidemiological index was proposed by Rompen et al. in 2001– the so called Periodontal Index of Risk of Infectiousness (PIRI).10 Methodology of this index was presented in Table 1. Usefullness of PIRI in public health aspects was investigated only in few studies and is not clearly proven.



The aim of the study was:

  1. Clinical evaluation of periodontium in patients with MI and stable CHD in Polish population.

  2. An attempt at assessing the association of varied clinical periodontal parameters, including PIRI index, with the risk of MI.

Material and methods. Research material constituted patients hospitalized in the 1st Department and Clinic of Cardiology, Medical University of Gdańsk, Poland, divided into 2 groups. Inclusion criterion for group 1 was a recent history of acute MI (less than 6 months prior to the research). Inclusion criterion for group 2 was minimum five years history of documented CHD without acute events.

The following patients were not included to the study:



  1. Patients undergoing chemotherapy, radiotherapy, immunosuppressive therapy or systemic steroid therapy

  2. Patients received periodontal treatment within the last 6 months prior to the study

  3. Patients treated with antibiotic within 2 weeks prior to the study

  4. Patients whose overall condition precluded an examination in a seated position

One hundred patients with MI and 100 patients suffering from stable CHD were included in the examination. The edentulous patients were excluded from further testing. The final study groups comprised 170 subjects:

Group 1 consisted of 86 individuals, who had undergone acute MI and included 33 female and 53 male, aged 41 to 82, mean 61.21 ± 7.89 years.

Group 2 consisted of 84 individuals suffering from stable CHD and included 35 female and 49 male aged 46 to 77, mean 62.15 ± 7.73 years.

Before the dental examination, a questionnaire was administered to all subjects to elicit data about well-known CHD/MI risk factors: nicotine usage, hyperlipidemia, hypertension, diabetes, family history of cardiovascular disease. This self-reported informations were confirmed by cardiologist using hospital medical records of each patients. Overweight was estimated according to Body Mass Index.

In all subjects the clinical examination was performed by single clinicist – a trained qualified periodontologist. The training procedure and methodology design were performed during pilot study.11

In clinical evaluation of oral hygiene level and periodontal conditions following indices were used: Aproximal Plaque Index (API) (according to Lange et al 12 ); modified Sulcus Bleeding Index (mSBI) (according to Mühlemann & Son 13); periodontal pocket probing depth (PPD) at six sites per tooth in millimetres (distance from pocket bottom to the gingival margin); clinical attachment loss (CAL) in millimetres at six sites per tooth (distance from pocket bottom to the cementoenamel junction); presence and class of furcations (according to worldwide used horizontal Hamp’s classification); Community Periodontal Index for Treatment Needs (CPITN) (the code of worst sextant was recorded for each subject); Periodontal Index of Risk of Infectiousness (PIRI) (according to Rompen et al 10 - Table 1).

Total number of present teeth and number of teeth with pocket 5 mm deep or above were also noted.

All measurements were performed using double-sided periodontometer PCPUNC15/11.5b (HuFriedy) with both UNC15 and WHO scales. For evaluation of furcations periodontometer LM 20B-21B according to Nabers (LM Instruments) was used. Measurements were rounded to the lowest whole mm.



Statistical analysis. The data distribution normality was evaluated using Shapiro-Wilk W test. According to the type of variable, the Mann-Whitney U-test or chi-square test (indicated in the footnotes of the tables) were used for demonstrating the differences between both groups for mean value of each parameter. In the next step continuous variables were categorized – dichotomized at the mean value - to accomplish the logistic regression model requirements. Then the odds ratios with 95% confidence intervals were calculated for bivariate associations between the studied variables and MI status. Finally the odds ratios between each periodontal parameter and MI status were estimated.using multiple logistic regression analysis (Statistica Software procedure: logit). Myocardial infarction presence was stated as dependent dichotomized variable. Following known general risk factors for MI were forced into the models as binary confounding factors: hyperlipidemia, diabetes, smoking, hypertension, overweight according to Body Mass Index, male gender and family history of cardiovascular disease. The odds ratios were calculated and associated with 95% confidence interval (CI). All results were considered to be significant at the level of p<0.05 or p<0.001. Calculations were done using Statistica Data Analysis Software System, ver. 7.1 (StatSoft Inc., 2005).

Ethical aspects of the research followed the World Medical Association Declaration of Helsinki. The study was approved by the Ethics Committee of the Medical University of Gdańsk.



Results. Table 2 shows demographic characteristics, mean number of teeth, mean values of oral hygiene index and clinical periodontal parameters in evaluated groups. Unless otherwise specified, values were expressed as mean ± standard deviation. Cases (MI) and controls (stable CHD) were comparable in group size, age, gender and number of teeth. Low, comparable oral hygiene level in examined groups was noted. Mean values of PPD and PIRI were statistically higher in group 1 at significance level p<0.001. Significantly higher mean value of mSBI, CAL and number of teeth with pocket 5 mm or above were also noted in group 1. Healthy periodontium (CPI code 0) was observed only in 3.49 % individuals from group 1 and 4.76 % individuals from group 2, and this difference was no significant. Advanced chronic periodontitis (CPI code 4) was diagnosed in significantly higher percentage of subjects in group 1 in comparison with group 2 (65.12 % versus 38.10%; significance level p<0.001).

Table 3 shows prevalence of known general MI risk factors in evaluated groups.

In Table 4 bivariate association between MI status and periodontal health variables are presented. Among used periodontal examinations’ variables parameters PPD, CAL and PIRI index were most highly correlated with risk of MI (OR 9.37, 9.94 and 14.12 respectively). Simple diagnosis of chronic periodontitis (CPI code 3 or 4) was not significantly correlated with MI status.

Data from multiple regression analysis, comparing group 1 and 2, adjusted for known MI risk factors (displayed in Table 3), is demonstrated in Table 5. Calculated odds ratio for parameter PIRI as MI risk factor (12.92) was significant, however with wide 95% confidence interval, amounting 1.06-452.7.



Discussion. Both periodontitis and CHD are social diseases and serious problem for public health services. The obtained data confirms widespread periodontitis in patients suffering from CHD and MI as well as a advanced periodontal tissue destruction and considerable periodontal treatment needs in this population. In our study oral hygiene levels in both groups were comparable low, but this scores could be worse due to hospital stay. Also mean SBI value, significantly worse in group 1, could be increased by anticoagulant drugs, usually received by MI sufferers. In own research a considerably lower level of destruction of periodontal tissues was noticed in group 2 (stable CHD) as compared to group 1 (MI sufferers). This is corroborated by reports by Emingil et al 14, who noticed a significantly higher number of periodontal pockets > 4mm in a group of 60 acute MI sufferers as compared to the group of 60 people with stable CHD. The authors have also demonstrated significantly higher intensity of gingivitis in the MI patients, which was also noted in our material.

Cueto et al 15 published results of research carried out on a 72 person group of patients with MI as well as the control group consisting of 77 individuals treated in the traumatological ward. The average pocket depth in this group was 2.61 mm, and the average clinical attachment loss was 4.03 mm. In the control group these values were considerably lower – 2.27 mm and 2.93 mm respectively. In the logistic regression model it was confirmed that periodontitis is a risk factor for MI with odds ratio 4.42. After adjusting for confounding risk factors in multiple analysis it reached the value of 3.31. Different results, based on the American NHANES I program were published by Hujoel et al.4 Prospective analysis encompassed 8032 individuals with negative cardiological medical history. For people suffering from periodontitis as compared to people with healthy periodontium, the relative risk of CHD was calculated at 2.66 - not counting the confounding factors. Including the generally recognized risk factors, the risk ratio was calculated at 1.14, with statistically insignificant 95% confidence interval at 0.96-1.36.

In meta-analysis based on the results of 8 follow-up and 1 retrospective studies (total 107 thousand patients examined), Janket et al 16 determined summary relative risk factor for CHD in patients with periodontitis at 1.19. In patients below the age of 65, the RR reached 1.44. The summary relative risk of death because of MI was calculated at 1.54.

As mentioned in the introduction, many authors underline controversy in the choice of parameters for clinical assessment of periodontium tested in logistic regression models as potential risk factors for CHD and MI. They sometimes introduce own epidemiological indices and scales for assessing the advance of periodontitis. Offenbacher & Beck17 indicate the importance of these parameters in the course of periodontological clinical examination, which influence systemic proinflammatory factors’ levels to the greatest extend. According to cited authors these are: the pocket probing depth (PPD) and bleeding on probing based factors (for example BOP or SBI factors). They consider parameters assessing remote results of periodontitis, such as clinical attachment loss (CAL), as less useful.

Non-homogenous methodology of published studies convinces researchers to adopt many parameters for assessing the condition of periodontium and prove that statistic correlations for each of them in relation to CHD/MI are similar. The publication by Montebugnoli et al18, who used as many as four different indices proposed by Matilla et al1 in their pioneering work in this field, may be held as an example here. These indices (Total Dental Index, Panoramic Tomography Score, Clinical Periodontal Sum Score and Clinical Radiographic Sum Score) are based on clinical and radiological examination of teeth and periodontium. The odds ratio of CHD was significant for each of the used indices and calculated 20.81, 5.14, 4.61 and 4.70 respectively. Similar observations were made by Andriankaja et al.19 The main conclusion of their publication was to notice similar correlations between periodontitis and MI in the broad range of indices and variables used to assess the periodontal disease’s advance.

In contrast to the afore mentioned authors, Renvert et al20 use the periodontal pentagon risk diagram in search of a parameter best correlated with MI risk. This diagram includes five elements: nicotine usage, the percentage of pockets 6mm or deeper, the percentage of teeth with 4 mm or more alveolar bone loss, the number of teeth and the bleeding on probing (BOP) index. The results demonstrated that the best individual parameter for assessing the periodontal status in research of this kind is the alveolar bone loss.

In the light of the above data, the Periodontal Index of Risk of Infectiousness (PIRI) proposed by Rompen et al10 and used in our study, seems to be promising. This index relies on combined evaluation of two potential periodontal infections’ foci – the periodontal pocket and involved interradicular area - furcation. Depending on PIRI value, oscillating from 0 to 10, patients are classified to three groups of potential risk of systemic influence of bacterial flora of the pathological periodontal areas: low risk (PIRI=0), moderate risk (PIRI from 1 to 5) and high risk group (PIRI from 5 to 10). In contrast to the previously used indices, PIRI not only assesses the depth of periodontal pockets or the presence of furcations, but also their number in each patient. The aim of such an assessment is to individually assess the surface of inflammed periodontium, which doesn’t provide for a tight barrier between the bacterial biofilm and the intracorporeal environment, understood as a gate for a potential prolonged release of bacteria, toxins and inflammatory mediators into circulation.

Geerts et al21 used the PIRI factor as one of the parameters of periodontal evaluation in case-control study encompassing 108 subjects with CHD hospitalised in the University Hospital Liege, Belgium. The control group consisted of 62 patients from the dental clinic in whom cardiovascular diseases and their potential symptoms were excluded basing on individual questionnaires. Patients earlier subjected to periodontal therapy were excluded from the research. The average PIRI in the evaluated group was 4.9 ±2.7 and in control group 3.1± 2.7. The percentage of individuals with high systemic risk (PIRI = 6-10) in the test group was 38.9% and was statistically significantly higher than in the control group (19.3%). However for persons with moderate risk (PIRI 1-5) significant difference between group was not demonstrated. Using multiple regression the authors demonstrated that the presence of periodontal infections’ foci estimated by means of the PIRI is correlated with the presence of CHD with an adjusted odds ratio of 1.3 for each unit on the PIRI scale. Patients with the highest PIRI score had a 13.8 times higher statistical risk of having CHD than subjects with the lowest scores. Our results are quite similar - in own material statistic analysis demonstrated highly significant differences of mean PIRI values between group with MI and stable CHD. Odds ratio 6.22 was calculated for affiliation to high risk group according to PIRI, understanding as binary parameter. Adjusted multivariative regression model, comparing groups 1 and 2, demonstrated that PIRI may be considered a significant risk factor for MI with odds ratio 12.92. However, 95% confidence interval is highly imprecise.



The large variation in the results of studies about relationships between periodontal disease and CHD / MI might be explained partially by the fact of confounding and effect modifications. Effect modification occurs when the influence of risk factor on outcome disease depending of another variable. For example, Ylöstalo et al 22 conclude, that HDL levels appear to modify the association between periodontal infection and certain parameters of subclinical atherosclerosis. But generally nicotine usage is pointed out as major effect modifier in this type studies, because it is a risk factor both for periodontitis and CHD/MI. Based on Third NHANES data, Hyman et al 23 suggest, that correlation between periodontal disease and CHD was limited to smokers. Analysing these controversies Hyman24 and Ylöstalo & Knuttila25 suggest wider use of stratification methods for better controlling interactions between tested variables. In our study we don’t use stratification method to assess potential effect modifications of smoking or other variables. This could be included to limitations of our study and will be subject of further analysis. Not very large study groups and case-control type of research could be also consider as potential limitations of our study. Thus conclusions should be formulated with utmost care and indicates the need to analyse more clinical material with control of potential confounding and effect modifications. It seems premature to consider PIRI as the best parameter in assessing periodontitis as a potential independent MI risk factor. However, the results obtained so far encourage wider use of this factor in epidemiological research into the subject under discussion, in particular on large research material in prospective studies. In all postulated hypotheses about interdependences between periodontitis and cardiovascular diseases, the diseased periodontium is supposed to be a source of release of bacterial pathogens and/or proinflammatory agents into the bloodstream.26 There are no publications about possible correlations of PIRI value with proinflammatory mediators’ levels in serum. This research aim seems to be interesting. In contrast to classical epidemiological indices, PIRI was designed to give a quick estimation of the surface area of the interface between the subgingival plaque and damaged epithelial walls of periodontal pockets. Thus, the potential confirmation of epidemiological correlation of PIRI with CHD/MI risk may have important practical applications in dental public health programmes. In the prophylaxis aspect PIRI may become useful in relatively simple screening assessment of the potential influence of periodontium on circulation and indicate the therapeutic direction towards quick reduction of such risk. Analysing the methodology of this index we may conclude, that single very deep pockets constitute a higher danger than for example numerous pockets of range 5 mm. Limiting the potential negative influence of periodontal niches on cardiovascular system would then require, first of all, eliminating the deepest pockets as well as class II/III furcations.

It is not yet clear whether or not periodontal therapy aimed at eliminating local infection and in consequence reducing systemic inflammation results in a reduced risk of CHD / MI. Scannapieco et al27 concluded that there was as yet insufficient evidence available to recommend periodontal treatment to reduce the risk of cardiovascular diseases, and there were no interventional trials directly evaluating the impact of periodontal treatment on risk of CHD / MI.

Nevertheless a number of studies have analyzed correlations between treatment of periodontitis and cardiovascular parameters. D'Aiuto et al8 have examined the effect of non-surgical periodontal treatment on serum CRP and IL-6 levels measured using a high sensitivity assay (hs-CRP) and ELISA, respectively. Significant reductions of marker’ levels between baseline and 6-month posttreatment were observed. Tonetti et al28 revealed, that intensive periodontal therapy results in an improvement in endothelial function. Taylor et al29 in their randomized controlled trial observed, that initial periodontal treatment - a relatively simple and cost-effective intervention - may have positive systemic effects, for example lower fibrinogen levels.

Offenbacher & Beck 30 concluded, that randomized controlled trials were necessary to definitively answer the question of causality between periodontitis and periodontal treatment and cardiovascular diseases. Additional data is also required for prove the potential cardioprotective benefits of periodontal therapy in public health system. As mentioned by some authors24,25 such a type of research should be focused on proper control of confounding and effect modifications. Considering incomplete uniformity of published results, further investigation should be performed.


: prace -> upload -> 2011
2011 -> Analiza zwarcia niezbędny element podstawowego badania stomatologicznego
2011 -> Powikłania kolczykowania jamy ustnej. Complications of oral piercing
2011 -> Małgorzata Wierzbicka, Tomasz Kopeć, Katarzyna Nowak, Joanna Jackowska, Witold Szyfter
2011 -> Staw skroniowo-żuchwowy u dzieci chorujących na młodzieńcze idiopatyczne zapalenie stawów
2011 -> Kliniczne zastosowanie jva w diagnostyce układu stomatognatycznego
2011 -> A dr n med. Janina Czuryszkiewicz-Cyrana
2011 -> Procesy odrzucania przeszczepów na podstawie piśmiennictwa i obserwacji własnych Streszczenie
2011 -> Związek chorób naczyń i chorób przyzębia przegląd piśmiennictwa
2011 -> Wpływ chemicznych środków do retrakcji dziąsła brzeżnego na czas polimeryzacji winylosiloksanoeterowego elastomeru wyciskowego w badaniach reometrycznych
2011 -> Evaluation of the radiopacity of root canal filling materials Summary Aim of the study


  1   2   3


©absta.pl 2019
wyślij wiadomość

    Strona główna