Alveolar defects before and after surgically assisted rapid palatal expansion (SARPE): a CBCT assessment

ABSTRACT Introduction: Surgically Assisted Rapid Palatal Expansion (SARPE) promote maxillary expansion in skeletally mature patients. This technique is effective; however, some side effects are still unknown. Objectives: evaluate the presence of alveolar defects (dehiscences and fenestrations) in patients submitted to the SARPE. The null hypothesis tested was: SARPE does not influence the number of dehiscences and fenestrationss. Methods: A retrospective quasi-experiment study of a convenience sample of 279 maxillary teeth, in 29 patients evaluated with Cone Beam Computed Tomography (CBCT) at T1 (before SARPE), T2 (after expansion) and T3 (after retention), was performed. The examined teeth were: canines, first and second premolars, first and second molars. in axial, coronal, and cross-sectional views. The evaluations involved viewing slices from mesial to distal of the buccal roots. Results: All statistical analyses were performed using SAS 9.3 and SUDAAN softwares. Alpha used in the study was 0.05. Alveolar defects increased statistically from T1 (69.0%) to T2 (96.5%) and T3 (100%). Dehiscences increased 195% (Relative Risk 2.95) at the end of expansion (T2). After retention (T3), individuals were on average 4.34 times more likely to develop dehiscences (334% increase). Fenestrations did not increase from T1 to T2 (p = 0.0162, 7.9%) and decreased from T2 to T3 (p = 0.0259, 4.3%). Presence of fenestrations at T1 was a significant predictor for the development of dehiscences in T2 and T3. Dehiscences increased significantly in all teeth, except second molars. Conclusion: The null hypothesis was rejected. After SARPE the number of dehiscences increased and fenestrations decreased. Previous alveolar defects were predictor for dehiscences after SARPE.

RESUMO Introdução: A expansão rápida da maxila assistida cirurgicamente (ERMAC) promove expansão em pacientes esqueleticamente maduros. Essa técnica é efetiva; entretanto, alguns efeitos colaterais ainda são desconhecidos. Objetivos: Avaliar a presença de defeitos alveolares (deiscência e fenestração) em pacientes submetidos à ERMAC. A hipótese nula testada foi que a ERMAC não influenciaria o número de deiscências e fenestrações. Métodos: Foi realizado um estudo quase-experimental de uma amostra de conveniência de 279 dentes superiores, de 29 pacientes que foram avaliados por meio de tomografia computadorizada de feixe cônico (TCFC) em T1 (antes da ERMAC), T2 (após expansão) e T3 (após contenção). Caninos, primeiros e segundos pré-molares, primeiros e segundos molares foram examinados em cortes axiais, coronais e sagitais. As raízes vestibulares desses dentes foram avaliadas da face mesial até a distal. Resultados: Todas as análises estatísticas foram realizadas usando os softwares SAS 9.3 e SUDAAN. O alfa usado no estudo foi de 0,05. Os defeitos alveolares aumentaram significativamente de T1 (69,0%) para T2 (96,5%) e T3 (100%). Deiscências aumentaram 195% (risco relativo de 2,95%) no final da expansão (T2). Após contenção (T3), os pacientes tiveram, em média, 4,34 vezes mais chance de desenvolver deiscência (334% de aumento). As fenestrações não aumentaram de T1 para T2 (p= 0.0162, 7.9%) e diminuíram de T2 para T3 (p = 0.0259, 4,3%). A presença de fenestrações em T1 foi um preditor significativo para o desenvolvimento de deiscências em T2 e T3. Deiscências aumentaram significativamente em todos os dentes, exceto nos segundos molares. Conclusão: A hipótese nula foi rejeitada. Após a ERMAC, o número de deiscências aumentou e o de fenestrações diminuiu. Defeitos alveolares prévios foram preditores de deiscências após a ERMAC.

Quantification of pro-inflammatory cytokines and osteoclastogenesis markers in successful and failed orthodontic mini-implants

Abstract Objectives: Miniscrew has been frequently used, considering that anchorage control is a critical point in orthodontic treatment, and its failure, the main adverse problem. Using two groups of stable (successful) and unstable (failed) mini-implants, this in vivo study aimed to quantify proinflammatory cytokines IL-1 α, IL-6, IL-17, and TNF-α and osteoclastogenesis marker RANK, RANKL, and OPG in gingival tissue, using the real-time polymerase chain reaction technique. Methodology: Thirteen patients of both sexes (11-49 years old) under orthodontic treatment were selected, obtaining 11 successful and 7 failed mini-implants. The mini-implants were placed and removed by the same surgeon, in both jaws. The mean time of permanence in the mouth was 29.4 months for successful and 7.6 months for failed mini-implants. At removal time, peri-mini-implant gingival tissue samples were collected and processed for quantification of the proinflammatory cytokines and osteoclastogenesis markers. Nonparametric Wilcoxon rank-sum test considering the clusters and Kruskal-Wallis test were used for statistical analysis (α=0.05). Results: No significant difference (p>0.05) was observed between the groups for either quantification of cytokines or osteoclastogenesis markers, except for IL-6 (p<0.05). Conclusions: It may be concluded that the expression of IL-1α, IL-17, TNF-α, RANK, RANKL, and OPG in peri-implant gingival tissue were not determinant for mini-implant stability loss, but the higher IL-6 expression could be associated with mini-implant failure.

Successful and failed mini-implants: microbiological evaluation and quantification of bacterial endotoxin

Abstract Objectives Using two groups of mini-implants (successful and failed) the objectives of this in vivo study were: to evaluate the microbial contamination by the checkerboard DNA-DNA hybridization technique and to quantify the bacterial endotoxin by the limulus amebocyte lysate assay. Material and Methods The 15 successful and 10 failed mini-implants (1.6 mm diameter × 7.0 or 9.0 mm long), placed in the maxilla and/or mandible, were obtained from 15 patients undergoing orthodontic treatment. Data were analyzed statistically by the Wilcoxon rank-sum test using the SAS software (a=0.05). Results All 40 microbial species were detected in both groups of mini-implants, with different frequencies. No differences were observed between the groups with respect to microbial complexes (blue, purple, yellow, green, orange, red and other species) and endotoxin quantification (p>0.05). Conclusion Neither microbial contamination nor endotoxin quantification was determinant for the early loss of stability of the mini-implants.

Microbiological Evaluation of Different Irrigation Protocols on Root Canal Disinfection in Teeth with Apical Periodontitis: An In Vivo Study

The present in vivo study was designed to evaluate the efficacy of apical negative pressure irrigation (ANP), passive ultrasonic irrigation (PUI) and positive pressure irrigation (PP) in the reduction of intracanal bacteria of dogs' teeth with pulp necrosis and apical periodontitis. Eighty root canals were randomly distributed into 3 experimental and 2 control groups according to the irrigation delivery system: group ANP (n=20), group PUI (n=20), group PP (n=20), group PC (positive control – sterile saline irrigation; n=10) and group NC (negative control - vital pulps not subjected to bacterial inoculation; n=10). The first sample (S1) was collected at baseline, and the second sample (S2) was collected after the disinfection protocols. All samples were seeded in culture media for anaerobic bacteria. CFU counts were analyzed statistically by the Kruskal-Wallis, Dwass-Steel-Critchlow-Fligner post-hoc and Chi-square followed by Tukey like multiple comparisons for proportions (α=0.05). All experimental groups were effective in reducing Gram-positive bacteria compared with PC (p<0.05). Regarding the reduction of Gram-negative bacteria, group ANP was significantly better than PP (p<0.05). No statistically significant difference could be found between PP and PUI (p>0.05). In dog's teeth with apical periodontitis, the use of ANP and PUI can be considered promising disinfection protocols as both delivery systems promoted a significant bacterial reduction.

O presente estudo foi conduzido para avaliar a eficácia da irrigação por pressão apical negativa (ANP), irrigação ultrassônica passiva (PUI) e irrigação por pressão positiva (PP) na redução do número de bactérias presentes nos canais radiculares de dentes de cães com necrose pulpar e lesão periapical. Um total de 80 canais radiculares foram aleatoriamente distribuídos em 3 grupos experimentais e 2 grupos controles, de acordo com o sistema de irrigação empregado: grupo ANP (n=20), grupo PUI (n=20), grupo PP (n=20), grupo PC (controle positivo – irrigação com solução salina; n=10) e grupo NC (controle negativo – tecido pulpar com vitalidade, não submetido à contaminação bacteriana; n=10). A primeira amostra (S1) foi coletada no início do estudo, e a segunda amostra (S2) foi coletada após a utilização dos protocolos de irrigação. Todas as amostras foram semeadas em meio de cultura para micro-organismos anaeróbios. As contagens de unidades formadoras de colônia (cfu) foram analisadas estatisticamente por meio dos testes de Kruskal-Wallis, pós-teste de Dwass-Steel-Critchlow-Fligner e teste do qui-quadrado seguido do teste Tukey like para comparações múltiplas (α=0,05). Todos os grupos experimentais foram efetivos na redução de micro-organismos Gram-positivos, comparados ao grupo PC (p<0,05). Com relação à redução de microorganismos Gram-negativos, o grupo ANP foi significantemente melhor que o PP (p<0,05). Não foi possível observar diferença estatisticamente significante entre os grupos PP e PUI (p>0,05). Conclui-se que, em dentes de cães com periodontite apical, os sistemas de irrigação ANP e PUI podem ser considerados métodos promissores, uma vez que ambos os protocolos promoveram uma redução bacteriana significante.