Bruna de Carvalho Farias

A systematic review on the critical size defect model

OBJECTIVES To systematically review the literature data regarding the critical size defect (CSD) in adult rat calvaria and to determine which defect dimensions could be considered as being critical size. MATERIAL AND METHODS A literature search was conducted at Ovid Medline and Embase up to July 2012. Studies presenting with at least one of the primary outcomes of interest (number of defects with complete closure and the percentage of new bone formation (%NBF) in rat calvaria) were included. Screening, data extraction and quality assessment were conducted independently and in duplicate. RESULTS From 1461 citations, 257 full-text papers were screened and 61 papers were included in the analysis. Fourteen of 937 evaluated defects presented complete closure. Only 7 and 6 untreated sites in 5.0- and 6.0-mm-diameter defects, respectively, showed complete closure. A great variability among the preclinical models was seen, and the meta-analysis result showed a high heterogeneity regarding the mean %NBF. The mean %NBF according to the defect dimension was as follows: 18.29% and 21.44% for 5.0 mm central single defects at 1 and 3 months, respectively; 17.55%, 20.24% and 22.65% for 5.0 mm bilateral defects; 9.81%, 12.56% and 7.96% for 8.0 mm single defect; 11.18%, 9.48% and 26.24% for 9.0 mm single defects at 1, 2 and 3 months, respectively. CONCLUSION Calvarial defects with a diameter of 5.0 mm could be considered as a CSD. However, there is a necessity for further standardization of the rat calvaria model to enable more accurate comparison among future studies.

A systematic review of implant outcomes in treated periodontitis patients

OBJECTIVES To investigate the effect of treated periodontitis on implant outcomes in partially edentulous individuals compared with periodontally healthy patients. MATERIAL AND METHODS Longitudinal studies reporting on implant survival, success, incidence of peri-implantitis, bone loss and periodontal status, and on partially dentate patients with a history of treated periodontitis were included. RESULTS The search yielded 14,917 citations. Twenty-seven publications met the inclusion criteria for qualitative data synthesis. Implant success and survival were higher in periodontally healthy patients, whilst bone loss and incidence of peri-implantitis was increased in patients with history of treated periodontitis. There was a higher tendency for implant loss and biological complications in patients previously presenting with severe forms of periodontitis. The strength of the evidence was limited by the heterogeneity of the included studies in terms of study design, population, therapy, unit of analysis, inconsistent definition of baselines and outcomes, as well as by the inadequate reporting of statistical analysis and accounting for confounding factors; thus, meta-analysis could not be performed. CONCLUSIONS Implants placed in patients treated for periodontal disease are associated with higher incidence of biological complications and lower success and survival rates than those placed in periodontally healthy patients. Severe forms of periodontal disease are associated with higher rates of implant loss. However, it is critical to develop well-designed, long-term prospective studies to provide further substantive evidence on the association of these outcomes.

Occurrence of periodontal pathogens among patients with chronic periodontitis

The aim of the present study was to evaluate the presence of the periodontal pathogens that form the red complex (Tannerella forsythia, Porphyromonas gingivalis and Treponema denticola) and Aggregatibacter actinomycetemcomitans in patients with chronic periodontitis. The sample consisted of 29 patients with a clinical and radiographic diagnosis of chronic periodontitis based on the criteria of the American Academy of Periodontology (3). Samples for microbiological analysis were collected from the four sites of greatest probing depth in each patient, totaling 116 samples. These samples were processed using conventional polymerase chain reaction, which achieved the following positive results: 46.6% for P. gingivalis, 41.4% for T. forsythia, 33.6% for T. denticola and 27.6% for A. actinomycetemcomitans. P. gingivalis and T. forsythia were more prevalent (p < 0.05) in periodontal pockets ≥ 8 mm. The combinations T. forsythia + P. gingivalis (23.2%) and T. forsythia + P. gingivalis + T. denticola (20.0%) were more frequent in sites with a probing depth ≥ 8 mm. Associations with the simultaneous presence of A. actinomycetemcomitans + P. gingivalis, A. actinomycetemcomitans + T. forsythia, P. gingivalis + T. forsythia and T. forsythia + T. denticola were statistically significant (p < 0.05). It was concluded that the red complex pathogens are related to chronic periodontitis, presenting a higher occurrence in deep periodontal pockets. Moreover, the simultaneous presence of these bacteria in deep sites suggests a symbiotic relationship between these virulent species, favoring, in this way, a further progression of periodontal disease.

Non‐surgical treatment of gingival overgrowth induced by nifedipine: a case report on an elderly patient

Drug-induced gingival overgrowth (DIGO) is a significant problem for periodontologists and this side effect is frequently associated with three particular drugs: phenytoin, cyclosporin A and nifedipine. A case report of gingival overgrowth induced by nifedipine in an elderly patient treated with non-surgical periodontal therapy is described. A 75-year-old male with generalised gingival overgrowth reported the problem of oral malodour and significant gingival bleeding. The medical history revealed a controlled hypertensive state and Cerebral Vascular Accident (CVA) 3 years prior to consultation. The diagnosis was gingival overgrowth associated with nifedipine, no other risk factors being identified. The patient had been taking nifedipine for 18 months, but after the consultation with the patients doctor, nifedipine was suspended, as the hypertension was controlled. Treatment consisted of meticulous oral hygiene instruction, scaling, root surface instrumentation and prophylaxis. Six months after the first intervention, clinical parameters revealed a significant improvement with a considerable reduction in gingival overgrowth, demonstrating the effect of non-surgical periodontal therapy in severe cases of gingival overgrowth. Non-surgical treatment of DIGO is a far less invasive technique than surgical approaches and has demonstrated an impressively positive treatment response. It should therefore be considered as a first treatment option for DIGO.

Description of the periodontal pocket in preclinical models: limitations and considerations

Establishment of periodontal health and regeneration of the lost periodontal tissues are always the ultimate goal of periodontal treatment. The development of new therapeutic approaches raises the necessity for appropriate experimental models that present periodontal structures and healing capability comparable to humans. Preclinical research and extrapolation of the data to human conditions remains a stage of great importance before the clinical application of the new biomaterials and techniques. Periodontal pockets/defects in preclinical models can be induced experimentally through acute or chronic or a combination of both (induced) modalities. The features of the created defects and those of humans vary greatly mostly due to the nature of the periodontal disease. This is an important point to take into account, since it is well recognized that the potential of periodontal therapy may be dependent on both the biological background and the defect morphology. This review provides insight into the commonly used preclinical models for the reproduction of the periodontal pocket and discusses the advantages and disadvantages of each model in terms of similarity to human conditions, standardization and reproducibility.

Differences in the subgingival microbial population of chronic periodontitis in subjects with and without type 2 diabetes mellitus—a systematic review

ObjectivesThe purpose of this systematic review was to evaluate the available evidence in the literature in regard to the subgingival microbial population of chronic periodontitis in subjects with type 2 diabetes mellitus (T2DM+PD) compared to non-diabetic subjects (NDM+PD).Materials and methodsA literature search was conducted at Ovid MEDLINE and EMBASE database from 1980 to 2016, supplemented by hand searching as needed. Studies presenting with at least one of the primary outcomes (presence of any subgingival microorganisms, proportion and/or the amount of any subgingival plaque bacteria in T2DM+PD versus NDM+PD) were included. Screening, data extraction and quality assessment were conducted independently and in duplicate.ResultsFrom 611 citations, 19 full-text papers were screened and 11 articles were included for critical appraisal by both reviewers. Some evidence of a difference in the microbial profile between chronic PD subjects with and without T2DM was identified. The strength of evidence is strongest in Tannerella forthysia (T .forsythia) which was reported to be less frequent in the diabetic (T2DM+PD) group in five of the studies, followed by a weaker strength of evidence for other periodontal pathogens such as Porphyromonas gingivalis (P. gingivalis) and Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans), which were also found less frequent in the diabetic (T2DM+PD) group .ConclusionOnly few studies have compared T2DM+PD with NDM+PD. It is therefore strongly recommended that further studies which include four distinct groups of participants (NDM+PD, T2DM+PD, NDM+NPD, T2DM+NPD) instead of using intra-subject comparisons between healthy and diseased sites of the same subjects.Clinical relevanceDifferences in bacterial populations of T2DM+PD in comparison to NDM+PD subjects may indicate the need of different protocols for the treatment of the diabetic patients with periodontal disease.