Periodontal treatment downregulates protease-activated receptor 2 in human gingival crevicular fluid cells

Protease-activated receptor 2 (PAR2) is implicated in the pathogenesis of chronic inflammatory diseases, including periodontitis; it can be activated by gingipain and produced by Porphyromonas gingivalis and by neutrophil protease 3 (P3). PAR2 activation plays a relevant role in inflammatory processes by inducing the release of important inflammatory mediators associated with periodontal breakdown. The effects of periodontal treatment on PAR2 expression and its association with levels of proinflammatory mediators and activating proteases were investigated in chronic periodontitis patients. Positive staining for PAR2 was observed in gingival crevicular fluid cells and was reflective of tissue destruction. Overexpression of PAR2 was positively associated with inflammatory clinical parameters and with the levels of interleukin-6 (IL-6), IL-8, tumor necrosis factor alpha, matrix metalloprotease 2 (MMP-2), MMP-8, hepatocyte growth factor, and vascular endothelial growth factor. Elevated levels of gingipain and P3 and decreased levels of dentilisin and the protease inhibitors secretory leukocyte protease inhibitor and elafin were also associated with PAR2 overexpression. Healthy periodontal sites from individuals with chronic periodontitis showed diminished expression of PAR2 mRNA and the PAR2 protein (P < 0.05). Furthermore, periodontal treatment resulted in decreased PAR2 expression and correlated with decreased expression of inflammatory mediators and activating proteases. We concluded that periodontal treatment resulted in decreased levels of proteases and that proinflammatory mediators are associated with decreased PAR2 expression, suggesting that PAR2 expression is influenced by the presence of periodontal infection and is not a constitutive characteristic favoring periodontal inflammation.

Clinical and radiographic evaluation of intrabony periodontal defect treatment by open flap debridement alone or in combination with nanocrystalline hydroxyapatite bone substitute

The aim of this study has been to compare the clinical and radiographic outcome of periodontal intrabony defect treatment by open flap debridement alone or in combination with nanocrystalline hydroxyapatite bone substitute application. Thirty patients diagnosed with advanced periodontits were divided into two groups: the control group (OFD), in which an open flap debridement procedure was performed and the test group (OFD+NHA), in which defects were additionally filled with nanocrystalline hydroxyapatite bone substitute material. Plaque index (PI), gingival index (GI), bleeding on probing (BOP), pocket depth (PD), gingival recession (GR) and clinical attachment level (CAL) were measured prior to, then 6 and 12months following treatment. Radiographic depth and width of defects were also evaluated. There were no differences in any clinical and radiographic parameters between the examined groups prior to treatment. After treatment, BOP, GI, PD, CAL, radiographic depth and width parameter values improved statistically significantly in both groups. The PI value did not change, but the GR value increased significantly after treatment. There were no statistical differences in evaluated parameters between OFD and OFD+NHA groups 6 and 12months after treatment. Within the limits of the study, it can be concluded that the additional use of nanocrystalline hydroxyapatite bone substitute material after open flap procedure does not improve clinical and radiographic treatment outcome.

Four-year results following treatment of intrabony periodontal defects with an enamel matrix derivative alone or combined with a biphasic calcium phosphate

The aim of this study was to evaluate the 4-year clinical outcomes following regenerative surgery in intrabony defects with either EMD + BCP or EMD. Twenty-four patients with advanced chronic periodontitis, displaying one-, two-, or three-walled intrabony defect with a probing depth of at least 6 mm, were randomly treated with either EMD + BCP (test) or EMD alone (control). The following clinical parameters were evaluated at baseline, at 1 year and at 4 years after regenerative surgery: plaque index, gingival index, bleeding on probing, probing depth, gingival recession, and clinical attachment level (CAL). The primary outcome variable was CAL. No differences in any of the investigated parameters were observed at baseline between the two groups. The test group demonstrated a mean CAL change from from 10.8 ± 1.6 mm to 7.4 ± 1.6 mm (p < 0.001) and to 7.6 ± 1.7 mm (p < 0.001) at 1 and 4 years, respectively. In the control group, mean CAL changed from 10.4 ± 1.3 at baseline to 6.9 ± 1.0 mm (p < 0.001) at 1 year and 7.2 ± 1.2 mm (p < 0.001) at 4 years. At 4 years, two defects in the test group and three defects in the control group have lost 1 mm of the CAL gained at 1 year. Compared to baseline, at 4 years, a CAL gain of ≥3 mm was measured in 67% of the defects (i.e., in 8 out of 12) in the test group and in 75% of the defects (i.e., in 9 out of 12) in the control group. There were no statistically significant differences in any of the investigated parameters at 1 and at 4 years between the two groups. Within their limits, the present results indicate that: (a) the clinical improvements obtained with both treatments can be maintained over a period of 4 years, and (b) in two- and three-walled intrabony defects, the addition of BCP did not additionally improve the outcomes obtained with EMD alone. In two- and three-walled intrabony defects, the combination of EMD + BCP did not show any advantage over the use of EMD alone.

Bacterial profile and burden of periodontal infection in subjects with a diagnosis of acute coronary syndrome

BACKGROUND: Periodontitis has been identified as a potential risk factor in cardiovascular diseases. It is possible that the stimulation of host responses to oral infections may result in vascular damage and the inducement of blood clotting. The aim of this study was to assess the role of periodontal infection and bacterial burden as an explanatory variable to the activation of the inflammatory process leading to acute coronary syndrome (ACS). METHODS: A total of 161 consecutive surviving cases admitted with a diagnosis of ACS and 161 control subjects, matched with cases according to their gender, socioeconomic level, and smoking status, were studied. Serum white blood cell (WBC) counts, high- and low-density lipoprotein (HDL/LDL) levels, high-sensitivity C-reactive protein (hsC-rp) levels, and clinical periodontal routine parameters were studied. The subgingival pathogens were assayed by the checkerboard DNA-DNA hybridization method. RESULTS: Total oral bacterial load was higher in the subjects with ACS (mean difference: 17.4x10(5); SD: 10.8; 95% confidence interval [CI]: 4.2 to 17.4; P<0.001), and significant for 26 of 40 species including Porphyromonas gingivalis, Tannerella forsythensis, and Treponema denticola. Serum WBC counts, hsC-rp levels, Streptococcus intermedius, and Streptococcus sanguis, were explanatory factors to acute coronary syndrome status (Nagelkerke r2=0.49). CONCLUSION: The oral bacterial load of S. intermedius, S. sanguis, Streptococcus anginosus, T. forsythensis, T. denticola, and P. gingivalis may be concomitant risk factors in the development of ACS.

Oral prophylaxis and its effects on halitosis-associated and inflammatory parameters in patients with chronic periodontitis

OBJECTIVE A controlled clinical trial was conducted to evaluate the effects of oral prophylaxis on halitosis-associated, immunological and microbiological parameters. METHODS Thirty subjects were included in this controlled clinical trial (patients with generalized chronic periodontitis and controls without clinical attachment loss; each n = 15). Before oral prophylaxis and 14 days after (including tongue cleaning) volatile sulphur compounds (VSC), organoleptic scores and a tongue coating index were evaluated. The levels of IL-1β, IL-8, IL-10 and MMP-8 were measured in GCF, and also major periodontal pathogens were detected. Data were statistically analysed using anova and paired t-test. RESULTS Supragingival plaque and calculus removal with combined tongue cleaning was able to reduce significantly (P < 0.05) the VSC values in both groups (no significant differences between both groups). Two weeks after periodontal debridement, the VSC values were observed in the periodontitis group, but not in the control group, similar to the baseline values. The difference between the groups was statistically significant (P < 0.05). Only a repeated prophylaxis session in the periodontitis group was able to reduce VSC values significantly in comparison with baseline (P < 0.05). Organoleptic scores (10 and 30 cm) were significantly different (P < 0.05) between both groups before and after the treatment. Periodontal pathogens and host-derived markers were not significantly affected by a single prophylaxis session. CONCLUSIONS Oral prophylaxis may result in a significant decrease in VSC values. However, in periodontal diseases, a more complex treatment seems to be necessary.

Crevicular fluid biomarkers and periodontal disease progression.

AIM Assess the ability of a panel of gingival crevicular fluid (GCF) biomarkers as predictors of periodontal disease progression (PDP). MATERIALS AND METHODS In this study, 100 individuals participated in a 12-month longitudinal investigation and were categorized into four groups according to their periodontal status. GCF, clinical parameters and saliva were collected bi-monthly. Subgingival plaque and serum were collected bi-annually. For 6 months, no periodontal treatment was provided. At 6 months, patients received periodontal therapy and continued participation from 6 to 12 months. GCF samples were analysed by ELISA for MMP-8, MMP-9, Osteoprotegerin, C-reactive Protein and IL-1β. Differences in median levels of GCF biomarkers were compared between stable and progressing participants using Wilcoxon Rank Sum test (p = 0.05). Clustering algorithm was used to evaluate the ability of oral biomarkers to classify patients as either stable or progressing. RESULTS Eighty-three individuals completed the 6-month monitoring phase. With the exception of GCF C-reactive protein, all biomarkers were significantly higher in the PDP group compared to stable patients. Clustering analysis showed highest sensitivity levels when biofilm pathogens and GCF biomarkers were combined with clinical measures, 74% (95% CI = 61, 86). CONCLUSIONS Signature of GCF fluid-derived biomarkers combined with pathogens and clinical measures provides a sensitive measure for discrimination of PDP (ClinicalTrials.gov NCT00277745).

Increased periodontal inflammation in women with preterm premature rupture of membranes

OBJECTIVES To evaluate possible differences in periodontal inflammatory, microbiological and clinical parameters between women with preterm premature rupture of membranes (PPROM) and controls with uncomplicated pregnancies. MATERIALS AND METHODS Fifty-six women (32 test (PPROM) and 24 controls (uncomplicated pregnancies)) were examined at three time-points (T1: gestational weeks 20-35, T2: within 48 h after parturition, T3: 4-6 weeks after parturition). The examinations included assessment of the Periodontal Screening Index, collection of gingival crevicular fluid (GCF) and subgingival as well as vaginal bacterial sampling. RESULTS Periodontal inflammation was found to be higher in the test compared with the control group (p < 0.05) and decreased over time in both groups (p < 0.05). Microbiological outcomes showed no intergroup differences (p > 0.05) in prevalence of bacteria, but a decrease in subgingival periodontopathogens from T1 to T2 in the test group (p < 0.05) was observed. Interleukin (IL)-1β levels in GCF at T2 were not different between groups (p > 0.05). In women with PPROM, GCF levels of IL-8 (p < 0.05) and C-reactive protein (p < 0.05) were lower and IL-10 levels higher (p < 0.05) compared with controls. CONCLUSIONS Periodontal inflammation is elevated during pregnancy and seems to be more pronounced in women with PPROM. CLINICAL RELEVANCE The findings of the present study revealed an association between periodontal inflammation and PPROM, thus emphasizing the importance of optimizing self-performed oral hygiene in pregnant women.

The effects of erythritol air-polishing powder on microbiologic and clinical outcomes during supportive periodontal therapy: Six-month results of a randomized controlled clinical trial.

OBJECTIVES To characterize the physical characteristics of a new low abrasive erythritol powder (EPAP) and to evaluate its influence on the clinical and microbiologic parameters over a period of 6 months in patients undergoing supportive periodontal therapy (SPT). METHOD AND MATERIALS Prior to the clinical application, the particle size and abrasion level of EPAP were compared to glycine air-polishing powder (GPAP) ex vivo. Subsequently, 40 chronic periodontitis patients previously enrolled in SPT were randomly assigned into two groups for the treatment with subgingival EPAP or repeated scaling and root planing (SRP). At baseline (BL), bleeding on probing positive (BOP+) sites with probing pocket depth (PPD) of ≥ 4 mm but no detectable calculus were defined as study sites. During SPT, these sites were either treated by EPAP or SRP at BL, 3, and 6 months (3M, 6M). When indicated, additional SRP was provided. Plaque Index, BOP, PPD, clinical attachment level (CAL), and subgingival plaque were evaluated at BL and 6M. RESULTS EPAP yielded lower abrasiveness and smaller particle sizes when compared to GPAP. In 38 patients completing the study, EPAP and SRP resulted in significant reductions of BOP% (EPAP, 40.45%; SRP, 42.53%), PPD (EPAP, -0.67; SRP, -0.68), and increase of CAL (EPAP, 0.48; SRP, 0.61) while at 6M no statistically significant between-group differences were observed (P > .05). Microbiologic evaluation revealed minor shifts in the composition of the subgingival biofilm without influence on periodontopathogenic bacteria. CONCLUSION The subgingival use of EPAP by means of an air-polishing device may be considered safe and may lead to comparable clinical and microbiologic outcomes to those obtained with SRP. CLINICAL RELEVANCE The subgingival use of EPAP appears to represent a promising modality for the removal of subgingival biofilm during SPT.

Demographic and social factors which influence periodontal disease using the National Health and Nutritional Examination Survey (NHANES)

Periodontal diseases include the various forms of gingivitis and periodontitis. Scientific literature submits 80% of the population suffers from some form of periodontal disease. The comparison of studies measuring periodontal disease is difficult because researchers use various parameters and indexes to define disease severity. The purposes of this paper were to examine the associations of gingival bleeding and 3 or more millimeters periodontal attachment loss, and age, sex, income, race/ethnicity, current tobacco use, dental visits, health insurance, stroke, heart attack, and diabetes using the periodontal examination population from the National Health and Nutritional Examination Survey (NHANES) 1999-2004. ^ When all risk factors were analyzed in the model as a whole sex, race/ethnicity, poverty, and education were statistically significant for bleeding on probing. When all risk factors were analyzed in the model as a whole sex, age, and education were statistically significant for loss of attachment. ^

Avaliação dos efeitos do tratamento periodontal não cirúrgico sobre os sinais e sintomas da síndrome de Sjögren primária

A síndrome de Sjögren primária (SSp) é uma doença crônica autoimune sistêmica que pode levar à hipossalivação e afetar negativamente o ambiente oral. Os objetivos deste estudo foram detectar a influência da SSp nos níveis de biomarcadores inflamatórios na saliva e no fluido gengival nas amostras de pacientes com periodontite crônica, avaliar o efeito do tratamento periodontal não cirúrgico sobre os valores do índice clínico de avaliação da atividade sistêmica de pacientes com SSp e do índice reportado pelo paciente com SSp. Amostras de fluido gengival, saliva e os parâmetros clínicos periodontais que consistiram de medida da profundidade de sondagem (PS), nível clínico de inserção (NCI), sangramento à sondagem (SS) e índice de placa (IP) foram coletadas no início do estudo e 45 dias após a terapia periodontal não-cirúrgica de pacientes sistemicamente saudáveis com periodontite crônica (PC, n = 7) e pacientes com SSp e periodontite crônica (SP, n = 7). Pacientes periodontalmente saudáveis com SSp (SC, n = 7) e sistemicamente saudáveis (C, n = 7) também foram avaliados no início do estudo. Os grupos C, PC e SC foram pareados em gênero, idade e critério socioeconômico com o grupo SP. Os níveis de interleucina-8 (IL-8), IL-10 e IL-1ß foram avaliados por ensaio multiplex. Os níveis de atividade da doença foram medidos usando o Gold Standard da literatura chamado Índice Eular de atividade da síndrome de Sjögren (ESSDAI). Já para avaliação dos sintomas reportados pelo paciente com SSp foi utilizado o Índice Eular reportado pelo paciente com Sjögren (ESSPRI). Os parâmetros clínicos melhoraram após a terapia periodontal (p <0,05). No entanto, o NCI em pacientes com SSp não melhorou significativamente após a terapia (p> 0,05). Houve um aumento nos níveis de IL-1ß, IL-8 e diminuição dos níveis de IL-10 nas amostras de saliva de pacientes do grupo SC em comparação ao grupo C (p <0,05). Já em relação ao fluido gengival, pacientes do grupo SC tiveram maiores níveis de IL-1ß em comparação com o grupo C (p<0,05). Além disso, o tratamento periodontal não cirúrgico resultou num aumento dos níveis de IL-10 no fluido gengival no grupo SP e grupo PC em relação ao valor basal (p <0,05). O fluxo salivar foi significativamente aumentado após o tratamento periodontal apenas em pacientes do grupo SP (p = 0,039). Além disso, o tratamento periodontal não influenciou o índice ESSDAI (p = 0,35) e levou a uma diminuição significativa no índice ESSPRI (p = 0,03). Os presentes dados demonstraram que a SSp influencia os níveis salivares e de fluido gengival de biomarcadores inflamatórios em favor de um perfil próinflamatório, no entanto, este perfil parece não aumentar susceptibilidade dos indivíduos SSp à destruição periodontal. Além disso, os presentes dados demonstraram que o tratamento periodontal não-cirúrgico tem um impacto positivo sobre o fluxo salivar e sobre o índice ESSPRI de pacientes com SSp. Sugere-se assim que o tratamento periodontal pode melhorar a qualidade de vida de indivíduos com SSp.

Análise da imuno expressão das proteínas IL-17, IL-23 E RORγt na patogenia da doença periodontal

Periodontal disease is a chronic inflammatory condition primarily caused by bacteria in dental biofilm, which interact with the host, thus determining the nature of the resulting disease. Despite the wide knowledge about the pathogenesis of these diseases, the exact composition of the T cell profile during the active phase of the disease (Th1, Th2 or Th17) remains unknown. This study aimed to evaluate by immunohistochemical expression, the presence of the markers (IL-17, IL-23 and RORγt), involved in Th17 response in clinically healthy gingiva cases (n = 32), biofilm-induced gingivitis (n = 30), chronic periodontitis (n = 32) and aggressive periodontitis (n = 25), in order to analyze if the expression and/or distribution of these molecules in lymphocytes and macrophages, present in the inflammatory infiltrate of periodontal tissue, influences the tissue destruction observed in these diseases. The morphological analysis of cases was performed which assessed the intensity of the inflammatory infiltrate in mild, moderate and intense. For each case, in the area with the most representative immunostaining, 5 fields were chosen and analyzed, both for the intensity of the inflammatory infiltrate as for the quantity of immunostained cells, based on predetermined scores: score 0 (absence of inflammatory infiltrate/immunostaining), score 1 (the infiltrate/immunostaining covered less than 25% of the field area), score 2 (the infiltrate/immunostaining occupied between 25 and 50%) and score 3 (infiltrate/immunostaining present in over 50% of the field area). From this, a median was generated representing each case. The intensity of the inflammatory infiltrate correlated with the disease progression, in other words, it was crescent from clinically healthy gingiva to aggressive periodontitis (P <0.001). It was detected the presence of IL-17, IL-23 and RORγt in most of the evaluated cases and the number of immunostained cells correlated with the intensity of the inflammatory infiltrate (P <0.001) and with the clinical parameters analyzed (P <0.001), showing a positive correlation, mainly moderate. Aggressive periodontitis showed a higher percentage of immunostaining for all markers in relation to other clinical conditions assessed, suggesting a possible association of these markers with the progression of this disease, in which the higher the loss of periodontal support, the greater the amount of inflammatory infiltrate and larger the number of immunostained cells.

Estudo Clínico Longitudinal Comparativo da Condição Periodontal de Pilares Diretos de Próteses Parciais Removíveis Dento- Suportada e Dento-Muco-Suportada

Objective: To perform a long-term clinical evaluation of the periodontium of removable parti al denture (RPD) wearers, comparing the direct pillar teeth of tooth-supported and toothtissue supported RPDs. Method: Fifty patients with mean age of 45 years were enrolled in the study. The individuals were examined by a single examiner at the moment of denture installation and after 3, 6, 9 and 12 months. In each exam, the following parameters were verified: gingival recession (GR), probing depth (PD), plaque index (PI), gingival index (GI) e amount kerati nized mucosa (KM). All patients received oral hygiene instructions and prophylaxis and, when necessary, scaling and root planing. An analysis from the confidence interval was done to evaluate the endpoints regarding the type of denture in the direct pillar group. Results: The tooth-tissue supported dentures showed significantly higher GR, GI and PI values, and significantly lower KM values. Over time, neither of the types of denture presented statistically significant difference from the initial to the final examination for the parameters GR, PD, KM and GI, while the PI was significant only for the tooth-supported dentures. Conclusion: Pillar teeth adjacent to free ends presented a less favorable periodontal conditi on than the pillar teeth adjacent to intercalated spaces. However, the use of RPD did not aggravate the initial condition, after a follow-up period of 12 months. The findings of the study indicate that, within 1 year, there were no significant differences between the direct pillars of the toothsupported and tooth-ti ssue supported dentures, and suggest the need of professional follow up for a longer period.

Estudo Clínico Longitudinal Comparativo da Condição Periodontal de Pilares Diretos de Próteses Parciais Removíveis Dento- Suportada e Dento-Muco-Suportada

Objective: To perform a long-term clinical evaluation of the periodontium of removable parti al denture (RPD) wearers, comparing the direct pillar teeth of tooth-supported and toothtissue supported RPDs. Method: Fifty patients with mean age of 45 years were enrolled in the study. The individuals were examined by a single examiner at the moment of denture installation and after 3, 6, 9 and 12 months. In each exam, the following parameters were verified: gingival recession (GR), probing depth (PD), plaque index (PI), gingival index (GI) e amount kerati nized mucosa (KM). All patients received oral hygiene instructions and prophylaxis and, when necessary, scaling and root planing. An analysis from the confidence interval was done to evaluate the endpoints regarding the type of denture in the direct pillar group. Results: The tooth-tissue supported dentures showed significantly higher GR, GI and PI values, and significantly lower KM values. Over time, neither of the types of denture presented statistically significant difference from the initial to the final examination for the parameters GR, PD, KM and GI, while the PI was significant only for the tooth-supported dentures. Conclusion: Pillar teeth adjacent to free ends presented a less favorable periodontal conditi on than the pillar teeth adjacent to intercalated spaces. However, the use of RPD did not aggravate the initial condition, after a follow-up period of 12 months. The findings of the study indicate that, within 1 year, there were no significant differences between the direct pillars of the toothsupported and tooth-ti ssue supported dentures, and suggest the need of professional follow up for a longer period.

Marcadores de diagnóstico da doença periodontal

A periodontite é uma patologia inflamatória, causada pela interação entre o biofilme bacteriano e a resposta imune do hospedeiro e é caracterizada pela degradação de fibras colágenas do periodonto. Os avanços científicos possibilitaram o desenvolvimento de novas técnicas que possibilitem o diagnóstico precoce da doença, ou seja, prevenir a perda de inserção e progressão da periodontite. O diagnóstico da doença periodontal baseia-se em parâmetros clínicos como profundidade de sondagem, perda de inserção, hemorragia a sondagem e exames radiográficos. A análise dos biomarcadores presentes no fluido crevicular gengival (FCG) e saliva tem sido alvo de inúmeros artigos, uma vez que o fluido crevicular gengival (FCG) é composto de uma gama de biomarcadores celulares e moleculares. O presente trabalho teve como objetivo fazer uma revisão narrativa da literatura publicada a cerca dos métodos utilizados para diagnóstico precoce e prognóstico dos processos patológicos que podem estar presentes no periodonto. Foi realizada uma pesquisa bibliográfica online entre Dezembro de 2015 e Maio de 2016, com o objetivo de fazer uma revisão bibliográfica acerca do tema. Não foi estabelecido restrição quanto a data de publicação. Através da identificação da concentração de determinadas proteínas presentes no FCG é possível avaliar a atividade da doença periodontal e o prognóstico. Um importante número de marcadores como a elastase neutrofílica, prostaglandina E2, catepsinas, osteocalcina, -glucoronidase, colagenase, fosfatase alcalina, aspartato aminotransferase são citados (Genco et al., 1992). De acordo com a literatura publicada pode-se concluir que há alguns marcadores promissores para o diagnóstico precoce e prognóstico da doença periodontal, entretanto, não há ainda um marcador que possa identificar a futura perda de inserção ou a suscetibilidade à doença periodontal. São necessários estudos longitudinais para melhor entendimento do papel dos biomarcadores do FCG.

Modelação do risco de perda dentária por doença periodontal

O prognóstico da perda dentária é um dos principais problemas na prática clínica de medicina dentária. Um dos principais fatores prognósticos é a quantidade de suporte ósseo do dente, definido pela área da superfície radicular dentária intraóssea. A estimação desta grandeza tem sido realizada por diferentes metodologias de investigação com resultados heterogéneos. Neste trabalho utilizamos o método da planimetria com microtomografia para calcular a área da superfície radicular (ASR) de uma amostra de cinco dentes segundos pré-molares inferiores obtida da população portuguesa, com o objetivo final de criar um modelo estatístico para estimar a área de superfície radicular intraóssea a partir de indicadores clínicos da perda óssea. Por fim propomos um método para aplicar os resultados na prática. Os dados referentes à área da superfície radicular, comprimento total do dente (CT) e dimensão mésio-distal máxima da coroa (MDeq) serviram para estabelecer as relações estatísticas entre variáveis e definir uma distribuição normal multivariada. Por fim foi criada uma amostra de 37 observações simuladas a partir da distribuição normal multivariada definida e estatisticamente idênticas aos dados da amostra de cinco dentes. Foram ajustados cinco modelos lineares generalizados aos dados simulados. O modelo estatístico foi selecionado segundo os critérios de ajustamento, preditibilidade, potência estatística, acurácia dos parâmetros e da perda de informação, e validado pela análise gráfica de resíduos. Apoiados nos resultados propomos um método em três fases para estimação área de superfície radicular perdida/remanescente. Na primeira fase usamos o modelo estatístico para estimar a área de superfície radicular, na segunda estimamos a proporção (decis) de raiz intraóssea usando uma régua de Schei adaptada e na terceira multiplicamos o valor obtido na primeira fase por um coeficiente que representa a proporção de raiz perdida (ASRp) ou da raiz remanescente (ASRr) para o decil estimado na segunda fase. O ponto forte deste estudo foi a aplicação de metodologia estatística validada para operacionalizar dados clínicos na estimação de suporte ósseo perdido. Como pontos fracos consideramos a aplicação destes resultados apenas aos segundos pré-molares mandibulares e a falta de validação clínica.