Randomized clinical trials in periodontology: focus on outcomes selection

Abstract Randomized clinical trials (RCTs) are human studies carried out to compare different treatments or interventions, and their results are used to support clinical decision-making and improve patient care. Herein, the aim of this study was to review the selection process of study outcomes in periodontology. Primary outcomes should draw the main conclusions of the study, whereas secondary outcomes should only be used to help explain the main findings and generate future research hypothesis. Outcomes are classified as clinically relevant (CROs) or surrogate outcomes. CROs - the first option for primary outcome variables - should convey not only substantial health benefits, but also be deemed important by patients. In periodontology, tooth loss/retention and oral health-related quality of life (OHRQoL) are examples of CROs. While tooth loss has main limitations as a primary outcome, emerging evidence suggest that patient-reported outcome measures (PROMs) can accurately detect OHRQoL following periodontal therapy. When CROs cannot be assessed, validated surrogate outcomes can be used as proxies. Primary outcome variables should reflect a treatment endpoint at the patient level that can be easily used to inform decision-making in daily practice. These outcomes should allow the implementation of a treat-to-target concept in which the intervention can be clearly judged against a prespecified treatment target. Recently, the presence of at most 4 sites with periodontal probing depth ≥5 mm post-treatment was suggested as an effective endpoint for periodontal trials. In perspective, a combination of validated clinical parameters and PROMs will provide a more comprehensive assessment of periodontal treatments.

Análisis de flexión en alambres de níquel-titanio con y sin propiedades de transformación térmica / Bending analysis of nickel-titanium wires with and no thermal transformation properties

Objetivo: Evaluar el comportamiento de los alambres de aleación de níquel-titanio con y sin propiedades de transformación térmica en la relación carga/deflexión. Materiales y método: Para ello, 30 segmentos de alambres de níquel-titanio con calibre .014" y 30 mm de largo fueron cortados, conformando 10 segmentos de alambre Flexy NiTi de Orthometric®, 10 segmentos Flexy Copper NiTi termoactivado y 10 segmentos CuNiTi de OrmcoTM. Se usó una máquina universal de ensayos Instron® para analizar el comportamiento de carga y deflexión de los segmentos en una prueba de tres puntos, registrando las fuerzas alcanzadas en 0,5 mm: 1 mm, 2 mm y 4 mm de deflexión. Resultados: Hubo una diferencia estadísticamente significativa entre todos los alambres y entre todas las deflexiones, ya que el alambre Flexy Cooper NiTi presentó la menor carga entre todas las deflexiones analizadas. Conclusión: Se concluye que los alambres termoactivados alcanzan fuerzas más leves, lo que los hace más apropiados para alineaciones iniciales, las cuales requieren un mayor rango de deflexión(AU)

Microbial profile of symptomatic pericoronitis lesions: a cross-sectional study

Abstract Objective: The microbial composition of pericoronitis (Pc) is still controversial; it is not yet clear if the microbial profile of these lesions is similar to the profile observed in periodontitis (Pd). Therefore, the aim of the present study was to describe the microbial profile of Pc lesions and compare it directly with that of subjects with Pd. Methodology: Subjects with Pc and Pd were selected, and subgingival biofilm samples were collected from (i) third molars with symptomatic Pc (Pc-T), (ii) contralateral third molars without Pc (Pc-C) and (iii) teeth with a probing depth >3 mm from subjects with Pd. Counts and proportions of 40 bacterial species were evaluated using a checkerboard DNA-DNA hybridization technique. Results: Twenty-six patients with Pc and 18 with Pd were included in the study. In general, higher levels of microorganisms were observed in Pd. Only Actinomyces oris and Eubacterium nodatum were present in higher mean counts in the Pc-T group in comparison with the Pc-C and Pd-C groups (p<0.05). The microbiota associated with Pc-T was similar to that found in Pc-C. Sites with Pc lesions had lower proportions of red complex in comparison with the Pd sites. Conclusion: The microbiota of Pc is very diverse, but these lesions harbour lower levels of periodontal pathogens than Pd.

Does subgingival bacterial colonization differ between implants and teeth? A systematic review

Abstract The aim was of this study was to determine the current weight of evidence for the existence of specific differences between the microbiota of healthy teeth and healthy implants, or of teeth with periodontitis and implants with peri-implantitis. A systematic review was conducted according to the PRISMA statement. The MEDLINE, EMBASE and Cochrane databases were searched up to February 2018 for studies comparing microbiological data of biofilm samples collected from healthy teeth and implants or from teeth with periodontitis and implants with peri-implantitis. The weight of evidence was defined in three categories (strong, moderate and mild/some), according to the difference in number of studies showing statistically significantly higher counts and/or proportions and/or abundance and/or prevalence of microorganisms in health or in disease. Of the 132 articles identified, 8 were included. A wide range of microorganisms were present in different conditions but no microorganisms showed strong, moderate or mild/some evidence for a specific association with either teeth or implants. The results of this systematic review indicated that there is insufficient evidence in the literature to support specific differences between microorganisms colonizing teeth and implants, either in health or in disease.

Fibrina Rica en Plaquetas y Leucocitos en el tratamiento de defectos intra-óseos: Revisión Narrativa / Leucocyte and Platelet Rich Fibrin in the treatment of intra-bony defects. Narrative Review

RESUMEN: Diferentes técnicas quirúrgicas periodontales han surgido a lo largo del tiempo con el objetivo de lograr una regeneración periodontal y mejorar su predictibilidad. La Fibrina Rica en Plaquetas y Leucocitos (L-PRF) se ha posicionado como una alternativa para cumplir este objetivo, debido a que no requiere anticoagulantes en su preparación y muestra liberación sostenida de factores de crecimiento durante por lo menos 7 días. El objetivo de esta revisión narrativa es describir la evidencia disponible sobre el uso de L-PRF en defectos intra-óseos. Se realizó una búsqueda en las bases de datos MEDLINE y Cochrane Library, exploración manual y páginas web. De un total de 494 artículos recuperados, fueron seleccionados 12 publicaciones para esta revisión. Los resultados sugieren que L-PRF muestra beneficios al ser utilizada en el tratamiento periodontal regenerativo de defectos intra-óseos. Sin embargo, son necesarios ensayos clínicos con diseño metodológico estandarizado que permitan comparar L-PRF con biomateriales habitualmente empleados en el tratamiento de estos defectos.

ABSTRACT: Periodontal surgical techniques have emerged over time with the aim of achieving periodontal regeneration and improving its predictability. Leukocyte and Platelet-Rich Fibrin (L-PRF) has been proposed as an alternative, for not requiring anticoagulants in its preparation and for performing sustained release of growth factors for at least 7 days. The aim of this narrative review is to describe the available evidence on the use of L-PRF in periodontal intra-bony defects. An electronic and hand search was conducted in MEDLINE and Cochrane Library databases. Of 494 papers retrieved, 12 were selected for this review. The results suggest that even if L-PRF shows benefits when used in regenerative periodontal treatment of intra-bony defects, clinical trials with standardized methodological design are necessary to compare L-PRF with biomaterials usually used in these defects.

Evaluation of Enterococcus faecalis, Staphylococcus warneri and Staphylococcus aureus species in adults with generalized chronic periodontitis / Avaliação das espécies Enterococcus faecalis, Staphylococcus warneri e Staphylococcus aureus em adultos com periodontite crônica generalizada

ABSTRACT Objective: To identify and quantify the levels of three bacterial species that have recently been identified as potential "new" periodontal pathogens (Enterococcus faecalis, Staphylococcus aureus and Staphylococcus warneri) in subjects with periodontal health and generalized chronic periodontitis. Methods: Thirty adults with generalized chronic periodontitis and 10 periodontally healthy were included in this study. Nine subgingival biofilm samples were collected per subject and individually analyzed by checkerboard DNA-DNA hybridization technique. Results: The mean levels of E. faecalis and S. warneri were higher in chronic periodontitis than in periodontal health (p<0.05). Furthermore, a higher percentage of subjects with periodontitis were colonized by the three species evaluated in comparison with healthy subjects (p<0.05). This represented a difference of 40 percentage points between the two groups, for E. faecalis (present in 90% of individuals with periodontitis and 50% of the healthy individuals) and S. warneri (100% and 60%, respectively), and 26 percentage points for S. aureus (86% and 60%, respectively). Conclusion: E. faecalis and S. warneri have the potential to be periodontal pathogens. The role of S. aureus was less evident, since this species was more prevalent and at relatively higher levels in health than the other two species. These data might guide future studies on the role of these microorganisms in the etiology of periodontitis and help to establish more effective treatments for these infections.

RESUMO Objetivo: Identificar e quantificar os níveis de três espécies bacterianas que foram recentemente apontadas como possíveis "novos" patógenos periodontais (Enterococcus faecalis, Staphylococcus warneri e Staphylococcus aureus), em indivíduos periodontalmente saudáveis e com periodontite crônica generalizada. Métodos: A amostra foi composta por 30 indivíduos adultos com periodontite crônica generalizada e 10 periodontalmente saudáveis. Nove amostras de biofilme subgengival foram coletadas por indivíduo e analisadas individualmente pela técnica de checkerboard DNA-DNA hybridization. Resultados: Os níveis médios de E. faecalis e S. warneri foram maiores no grupo com periodontite crônica do que no de saúde periodontal (p<0,05). Além disso, um maior percentual de indivíduos com periodontite estavam colonizados pelas três espécies avaliadas em comparação com os indivíduos saudáveis (p<0,05). Essa diferença entre os dois grupos foi de 40 pontos percentuais para E. faecalis (presente em 90% dos indivíduos com periodontite e 50% dos saudáveis) e S. warneri (100% e 60%, respectivamente), e de 26 pontos percentuais para S. aureus (86% e 60%, respectivamente). Conclusão: E. faecalis e S. warneri tem potencial para serem patógenos periodontais. O papel do S. aureus foi menos evidente, uma vez que esta espécie estava mais prevalente e em níveis relativamente mais altos do que as outras duas espécies em saúde. Estes dados podem guiar futuros estudos sobre o papel dessas espécies na etiologia das periodontites e ajudar a estabelecer tratamentos mais eficazes para essas infecções.

Influence of glycemic control on the levels of subgingival periodontal pathogens in patients with generalized chronic periodontitis and type 2 diabetes

Abstract Objective This study evaluated the influence of glycemic control on the levels and frequency of subgingival periodontal pathogens in patients with type 2 diabetes mellitus (DM) and generalized chronic periodontitis (ChP). Material and Methods Fifty-six patients with generalized ChP and type 2 DM were assigned according to the levels of glycated hemoglobin (HbA1c) into one of the following groups: HbA1c<8% (n=28) or HbA1c≥8% (n=28). Three subgingival biofilm samples from sites with probing depth (PD)<5 mm and three samples from sites with PD≥5 mm were analyzed by quantitative Polymerase Chain Reaction (PCR) for the presence and levels of Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Eubacterium nodatum, Parvimona micra, Fusobacterium nucleatum ssp. and Prevotella intermedia. Results The mean counts of F. nucleatum ssp. were statistically significantly higher in the sites with PD≥5 mm of the HbA1c≥8% group (p<0.05). Frequencies of detection of T. forsythia, E. nodatum, P. micra and F. nucleatum ssp. were all higher in the sites with PD≥5 mm of the patients with HbA1c≥8%, compared with those of patients with HbA1c<8% (p<0.05). Frequency of detection of P. intermedia was higher in the sites with PD<5 mm of the patients with HbA1c≥8% than those of the patients with HbA1c<8% (p<0.05). Conclusions Poor glycemic control, as indicated by HbA1c≥8%, is associated with increased levels and frequencies of periodontal pathogens in the subgingival biofilm of subjects with type 2 DM and ChP.

Effectiveness of a pre-procedural mouthwash in reducing bacteria in dental aerosols: randomized clinical trial

Abstract The aim of this randomized, single blinded clinical trial was to evaluate the effect of a pre-procedural mouthwash containing cetylpyridinium chloride (CPC), zinc lactate (Zn) and sodium fluoride (F) in the reduction of viable bacteria in oral aerosol after a dental prophylaxis with ultrasonic scaler. Sixty systemically healthy volunteers receiving dental prophylaxis were randomly assigned to one of the following experimental groups (15 per group): (i) rinsing with 0.075% CPC, 0.28% Zn and 0.05% F (CPC+Zn+F), (ii) water or (iii) 0.12% chlorhexidine digluconate (CHX), and (iv) no rinsing. Viable bacteria were collected from different locations in the dental office on enriched TSA plates and anaerobically incubated for 72 hours. The colonies were counted and species were then identified by Checkerboard DNA–DNA Hybridization. The total number of colony-forming units (CFUs) detected in the aerosols from volunteers who rinsed with CPC+Zn+F or CHX was statistically significantly (p<0.05) lower than of those subjects who did not rinse or who rinsed with water. When all locations were considered together, the aerosols from the CPC+Zn+F and CHX groups showed, respectively, 70% and 77% fewer CFUs than those from the No Rinsing group and 61% and 70% than those from the Water group. The mean proportions of bacterial species from the orange complex were statistically significantly (p<0.05) lower in aerosols from the CPC+Zn+F and CHX groups compared with the others two groups. In conclusion, the mouthwash containing CPC+Zn+F, is effective in reducing viable bacteria in oral aerosol after a dental prophylaxis with ultrasonic scaler.