Prevalence of awake bruxism in the adult population: a systematic review and meta-analysis.

OBJECTIVES: To evaluate the prevalence of awake bruxism (AB) in the adult population. MATERIALS AND METHODS: Six main electronic databases and three sources of grey literature were searched to identify cross-sectional studies in which AB was assessed. The studies were independently selected by two reviewers in two phases, based on their eligibility criteria. The first one consisted of reading titles and abstracts, and the second one involved reading the full articles. The study quality assessment was obtained by using the "Joanna Briggs Institute Critical Appraisal Checklist for Studies Reporting Prevalence Data", and the "R Statistics" software was used to perform meta-analyses. RESULTS: Seventeen out of 3086 identified studies were included. None of the studies scored high in methodological quality across all 9 items of the JBI checklist. However, "the use of valid methods to identify pathology" and "appropriate statistical analysis" were considered to have high methodological quality in all the studies. The overall pooled prevalence of the meta-analysis was 15.44% (99% confidence interval: 10.81 to 20.72%) and there was no difference for sex, sampling method and according to consensus-based classification. CONCLUSIONS: The prevalence of AB in adults was low. There was substantial methodological variability, which highlights the need for standardized guidelines. CLINICAL RELEVANCE: Prevalence data are useful for raising patients' and clinicians' awareness of the AB. Moreover, since AB can lead to possible pain and overload of the stomatognathic system, this knowledge can also guide dentists to achieve an early diagnosis of AB and to provide appropriate care management.

Prevalence of postoperative pain after endodontic treatment using low and high concentrations of sodium hypochlorite: a systematic review and meta-analysis.

OBJECTIVES: To determine the prevalence of postoperative pain after endodontic treatment using low (LC) and high (HC) concentrations of sodium hypochlorite (NaOCl). MATERIALS AND METHODS: Six databases and the grey literature were searched to identify randomized clinical trials that evaluated postoperative pain after endodontic treatment using NaOCl. NaOCl concentrations were dichotomized into 'LC' (0.5% to 3%) and 'HC' (≥ 5%) and a proportion meta-analysis was applied to determine the postoperative pain prevalence: overall and according to pain intensity and postoperative time. The prevalence of patients using pain control medication was also determined. A significance level of 5% and a random effect model were applied for data analysis. Between-study heterogeneity was assessed by I2 index. Risk of bias (RoB) was assessed using the Cochrane Risk-of-Bias 2.0 tool. The certainty of evidence was assessed using the GRADE approach. RESULTS: Ten studies were included in the review and eight in the meta-analysis. The overall prevalence of postoperative pain was 45% in LC and 39% in HC. The prevalence of pain in LC and HC after 24 h was 25% and 40%, respectively. After 48 h, the prevalence decreased to 10% in LC and 25% in HC. 'Absent pain' was the most prevalent score. The prevalence of patients who used medication was 9% in LC and 15% in HC. Three studies were classified as 'high RoB', five as 'low RoB', and two as 'some concerns'. The certainty of evidence was very low. CONCLUSIONS: The overall prevalence of postoperative pain after endodontic treatment using LC and HC of NaOCl was 45% and 39%, respectively. CLINICAL RELEVANCE: Postoperative pain is common after endodontic treatment using NaOCl, but tends to decrease over time.

Disocclusion guides in occlusal splints on temporomandibular disorders and sleep bruxism: a systematic review.

OBJECTIVE: To determine the best disocclusion guidance in occlusal splints (OSs) to manage and treat temporomandibular disorder (TMD) and sleep bruxism (SB). STUDY DESIGN: The research was conducted on 7 major electronic databases and 3 gray literature sources. We included randomized trials, nonrandomized clinical trials, and before-and-after studies. The risk of bias (RoB) was assessed by Joanna Briggs Institute of Critical Appraisal Tools. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to grade the certainty of evidence. RESULTS: Qualitative synthesis included 16 surveys reporting data from 620 participants. Canine guidance (CG) was widely searched. Bilateral balanced occlusion (BBO) and CG significantly decreased pain levels compared with the placebo splint. Comparing between OS and absence of therapy, only CG was assessed and showed significant improvements on mouth opening, pain, sleep quality, and muscle activity. When compared different guide types among themselves, no significant improvement was founded in any evaluated outcome. Three studies presented high RoB, 7 presented moderate RoB, and 6 presented low RoB. CONCLUSIONS: It is suggested there is not enough evidence to support that there are any specific kind of guidance responsible for improving evaluated outcomes on TMD and SB.

Viscosupplementation in the upper and lower compartments of the temporomandibular joint checked by ultrasonography in an ex vivo and in vivo study.

Viscosupplementation (VS) of the temporomandibular joint (TMJ) aims to treat temporomandibular dysfunction (TMD) by stimulating synovial cells to improve intracapsular lubrication. The purpose of the present study was to assess a VS protocol planned with the aid of cone-beam computed tomography (CBCT) and checked by ultrasonography (US). The study was carried out in 3 stages. The first was to check the correspondence between the proposed facial reference points and the osseous components of the joint by means of CBCT. In the second stage, the upper and lower compartments of 20 TMJs of fresh frozen cadavers were injected with coloured liquids, and the accuracy of the technique was confirmed by dissecting the anatomical specimens. The third stage consisted of VS in 10 patients (20 TMJs), with real-time verification of the location of the needle tip by means of ultrasonography. CBCT confirmed the correct locations of the marked points used in the proposed VS protocol. The dissections showed that 13 of the 14 injections effectively reached the upper and lower compartments. The location of the needle tip was effectively verified by ultrasonography, confirming the correct access to both compartments. The proposed protocol was effective for accessing the upper and lower compartments of the TMJ. The evaluated protocol proved to be accurate, safe and clinically reproducible means of VS in the upper and lower compartments of the TMJ.

Sleep bruxism and obstructive sleep apnea: association, causality or spurious finding? A scoping review.

STUDY OBJECTIVES: To evaluate the available evidence on the putative relationships between sleep bruxism (SB) and, obstructive sleep apnea (OSA) to assess the extent of research on this topic, and to formulate suggestions for future research. METHODS: A scoping review including studies examining temporal and overall association and prevalence of SB and OSA was performed. Six main databases and gray literature were searched. The studies selection was conducted by three independent reviewers. A narrative synthesis of the results was carried out. RESULTS: Thirteen studies in adults and eight studies in children were finally included. The median of concomitant conditions prevalence was 39.3% in adults and 26.1% in children. Marked methodological variability was identified among studies in adults and even more when we compared detection methods in children. No significant association between OSA and SB emerged in most studies in adults, while an association may be possible in children. CONCLUSIONS: Based on the current literature, it is not possible to confirm that there is a relationship between SB and OSA in adults. In patients under pediatric care, although this association seems plausible, there is currently insufficient supportive evidence. Standardized validated methodologies for identifying SB should be consistently used in both populations before reaching any conclusion regarding such association. Furthermore, assessment of shared phenotypes between patients with SB and patients with OSA may reveal new insights that will contribute to personalized approaches aiming to optimize the management of such comorbidities.

Effects of stabilization splints on the signs and symptoms of temporomandibular disorders of muscular origin: A systematic review.

OBJECTIVE: To assess effects of stabilization splints on signs and symptoms of temporomandibular disorders of muscular origin compared to other treatments. METHODS: A search for articles via six electronic databases and gray literature was conducted. The risk of bias was evaluated with the Cochrane Collaboration tool. The Grading of Recommendations Assessment, Development and Evaluation approach determined the certainty of evidence. RESULTS: Ten articles were included. Stabilization splints (n = 160 subjects) were reported to be as effective as other treatments (n = 209 patients) on analyzed outcomes (pressure pain threshold, pain during chewing, mouth opening, spontaneous pain intensity and by palpation). Five studies were judged at low and five at some concerns of risk of bias. The certainty of evidence was very low for all outcomes. CONCLUSION: Positive effect on signs and symptoms of temporomandibular disorders of muscular origin, when managed with stabilization splint, could not be confirmed or refuted.

Association between primary headaches and temporomandibular disorders: A systematic review and meta-analysis.

BACKGROUND: The primary objective of this systematic review was to answer the following question systematically: Is there any association between primary headaches (PHs) and temporomandibular disorders (TMDs) in adults? TYPES OF STUDIES REVIEWED: The protocol was registered with the International Prospective Register of Systematic Reviews. The authors performed the search in 6 main databases and 3 gray literature sources. The included articles had to have adult samples. PHs must have been diagnosed using the International Classification of Headache Disorders, and TMDs must have been diagnosed using Research Diagnostic Criteria for Temporomandibular Disorders, Diagnostic Criteria for Temporomandibular Disorders, or International Classification of Orofacial Pain. Risk of bias was evaluated using the Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instrument tools. The meta-analysis was performed using Review Manager software, Version 5.4. Certainty of evidence was screened according to Grading of Recommendations Assessment, Development and Evaluation. RESULTS: Nine of 2,574 articles reviewed met the inclusion criteria for qualitative analysis and, of these, 7 met the inclusion criteria for quantitative analysis. Odds ratios (ORs) for painful TMD and tension-type headache (OR, 1.94 [95% CI, 0.56 to 6.76] to OR, 7.61 [95% CI, 1.84 to 31.48]), migraines (OR, 4.14 [95% CI, 1.38 to 12.43] to OR, 5.44 [95% CI, 3.61 to 8.21]), and chronic headaches (OR, 40.40 [95% CI, 8.67 to 188.15] to OR, 95.93 [95% CI, 12.53 to 734.27]) were calculated. Articular TMDs without pain were evaluated in 2 articles, and both did not show positive association with tension-type headache nor migraine. Three studies were classified as moderate risk of bias and 6 as low risk of bias. The certainty of evidence varied between very low and low. CONCLUSIONS AND PRACTICAL IMPLICATIONS: Recognizing the positive association between painful TMD and PHs can help dentists and physicians treat the pain and avoid it, or recommend the patient to a specialist.

Prevalence of temporomandibular joint disorders: a systematic review and meta-analysis.

OBJECTIVES: The aim of this systematic review was to evaluate the prevalence of temporomandibular joint disorders (TMJD) among the general population. MATERIALS AND METHODS: Five main electronic databases and three grey literature were searched to identify observational studies in which TMJD was diagnosed using the research diagnostic criteria (RDC/TMD) or diagnostic criteria (DC/TMD). The studies were blindly selected by two reviewers based on eligibility criteria. Risk of bias (RoB) was assessed using the Joanna Briggs Institute Critical Appraisal Checklist, and the "R" Statistics software was used to perform meta-analyses. RESULTS: From 2741 articles, 21 were included. Ten studies were judged at low RoB, seven at moderate, and four at high. The TMJD investigated were as follows: arthralgia, disk displacement (DDs) with reduction (DDwR), DDwR with intermittent locking, DDs without reduction (DDwoR) with limited opening, DDwoR without limited opening, degenerative joint disease (DJD), osteoarthritis, osteoarthrosis, and subluxation. The main results from prevalence overall meta-analyses for adults/elderly are as follows: TMJD (31.1%), DDs (19.1%), and DJD (9.8%). Furthermore, for children/adolescents are as follows: TMJD (11.3%), DDs (8.3%), and DJD (0.4%). Considering the individual diagnosis meta-analyses, the most prevalent TMJD is DDwR for adults/elderly (25.9%) and children/adolescents (7.4%). CONCLUSIONS: The overall prevalence of TMJD was approximately 31% for adults/elderly and 11% for children/adolescents, and the most prevalent TMJD was DDwR. CLINICAL RELEVANCE: Knowledge about the frequency of TMJD can encourage dentists to consider appropriate strategies for early and correct diagnosis and, if need be, correct management.

Incidence of root resorption after concussion, subluxation, lateral luxation, intrusion, and extrusion: a systematic review.

OBJECTIVE: Traumatic dental injuries often affect the dental hard tissues, periodontal tissues, and dental pulp. Root resorption (RR) is a significantly concerning phenomenon that could lead to loss of the traumatized tooth. The purpose of this systematic review was to analyze the incidences of different types of RR after concussion, subluxation, lateral luxation, intrusive luxation, and extrusive luxation. MATERIAL AND METHODS: Seven databases were electronically and manually searched for the identification of observational studies that evaluated the incidence of RR after luxation injuries. Following study selection, data extraction, and risk of bias assessment through MAStARI checklist, the GRADE quality of available evidence was assessed. RESULTS: In total, 14 studies were included in the present systematic review. Ten and four studies presented a moderate and low RoB, respectively, and the overall GRADE quality of evidence was "very low" for all outcomes. The highest incidence rates of RR were observed for teeth with intrusive luxation, followed by those with extrusive luxation, lateral luxation, subluxation, and concussion. In general, the most common type of RR documented for all injuries was inflammatory RR, followed by replacement RR, surface RR, and internal RR. CONCLUSIONS: Our findings suggest that RR most commonly occurs in association with intrusive luxation and by inflammatory RR. Awareness regarding the incidence of RR after injuries is useful for clinicians to minimize the risk and severity of its occurrence, because a late diagnosis of RR may limit treatment alternatives and result in tooth loss. CLINICAL RELEVANCE: Knowledge about the incidence of RR in teeth with concussion and different types of luxation injuries can ensure appropriate follow-up protocols and favorable outcomes.

Prevalence of dentofacial injuries among combat sports practitioners: A systematic review and meta-analysis.

BACKGROUND/AIM: Combat sports might result in injuries to the face and teeth. However, it is unclear how often they occur and which sports presents the highest rates. The aim of this study was to investigate the prevalence of dentofacial injuries in combat sports participants. MATERIAL AND METHODS: A systematic review was performed. Six main electronic databases and three grey literature databases were searched. Studies were blindly selected by two reviewers based on pre-defined eligibility criteria. Studies that evaluated the prevalence of dentofacial injuries (teeth, alveolar bone, jaw, lips, and/or cheekbones) among combat sports participants were considered eligible. Risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal Checklist. The software r statistics version was used to perform all meta-analyses. Cumulative evidence of the included articles was evaluated using GRADE criteria (Grading of Recommendations Assessment, Development and Evaluation). RESULTS: From 1104 articles found on all databases, 27 were finally included. Eighteen studies were judged at low, seven at moderate, and two at high risk of bias. The following sports were investigated: boxing, capoeira, fencing, jiu-jitsu, judo, karate, kendo, kickboxing, kung fu, muay thai, sumo, taekwondo, wrestling, and wushu. Results from the meta-analysis suggested a dental pooled prevalence of 25.2% (12.3%-40.8%, i2  = 100%) and dentofacial pooled prevalence of 30.3 (18.1%-44.1%, i2  = 100%). Considering the sports' categories individually, jiu-jitsu had the highest pooled prevalence of dentofacial injuries (52.9% [37.9%-67.8%, i2  = 92%]), while judo was the sport with the lowest pooled prevalence (25.0% [7.6%-48.2%, i2  = 98%]). Among Panamerican sports, boxing had the highest prevalence of dental injuries (73.7% [58.7%-86.3%, i2  = 0%]). For dentofacial injuries, the GRADE criteria were considered low. CONCLUSIONS: Overall pooled prevalence of dentofacial injuries in combat sports was approximately 30%. Raising awareness regarding the frequency of these injuries might encourage the use of protective devices and reduce complications related to these incidents.

Alternative to Avoid Tooth Discoloration after Regenerative Endodontic Procedure: A Systematic Review.

This systematic review aimed to evaluate whether alternative materials to conventional triple antibiotic paste (TAP - metronidazole, ciprofloxacin, and minocycline) and grey mineral trioxide aggregate (GMTA) could avoid tooth discoloration in teeth submitted to Regenerative Endodontic Procedure (REP). It was also investigated if dental bleaching is able to reverse the color of darkened teeth due to REP. The search was conducted in four databases (Medline via PubMed, Scopus, ISI Web of Science and BVS - Virtual health library), following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The retrieved papers were uploaded in the software EndNoteTM and two reviewers independently selected the studies and extracted the data. Only studies in humans (case reports, case series, clinical trials) were included in the review. From 1,122 potentially eligible studies, 83 were selected for full-text analysis, and 38 were included in the review. The included studies were mainly case reports (76.3 %). The studies described a total of 189 teeth submitted to REP. From these, about 54% of teeth presented some degree of discoloration. Most teeth presenting color alteration were treated with TAP, especially when combined with GMTA. Only three studies performed dental bleaching to restore the color of teeth and neither bleaching technique was able to restore the original color of the crowns. The use of alternative materials to TAP and GMTA, such as double antibiotic paste or Ca(OH)2 pastes and white mineral trioxide aggregate or BiodentineTM, reduces the occurrence of tooth discoloration.

Alternative to avoid tooth discoloration after regenerative endodontic procedure: a systematic review

Abstract This systematic review aimed to evaluate whether alternative materials to conventional triple antibiotic paste (TAP - metronidazole, ciprofloxacin, and minocycline) and grey mineral trioxide aggregate (GMTA) could avoid tooth discoloration in teeth submitted to Regenerative Endodontic Procedure (REP). It was also investigated if dental bleaching is able to reverse the color of darkened teeth due to REP. The search was conducted in four databases (Medline via PubMed, Scopus, ISI Web of Science and BVS - Virtual health library), following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The retrieved papers were uploaded in the software EndNoteTM and two reviewers independently selected the studies and extracted the data. Only studies in humans (case reports, case series, clinical trials) were included in the review. From 1,122 potentially eligible studies, 83 were selected for full-text analysis, and 38 were included in the review. The included studies were mainly case reports (76.3 %). The studies described a total of 189 teeth submitted to REP. From these, about 54% of teeth presented some degree of discoloration. Most teeth presenting color alteration were treated with TAP, especially when combined with GMTA. Only three studies performed dental bleaching to restore the color of teeth and neither bleaching technique was able to restore the original color of the crowns. The use of alternative materials to TAP and GMTA, such as double antibiotic paste or Ca(OH)2 pastes and white mineral trioxide aggregate or BiodentineTM, reduces the occurrence of tooth discoloration.

Resumo Esta revisão sistemática teve como objetivo avaliar se materiais alternativos à pasta tri-antibiótica convencional (TAP, em Inglês - metronidazol, ciprofloxacina e minociclina) e ao agregado trióxido mineral cinza (MTA cinza) poderiam evitar a descoloração dentária em dentes submetidos ao procedimento endodôntico regenerativo (REP, em Inglês). Também foi investigado se o clareamento dental é capaz de reverter a cor dos dentes escurecidos devido ao REP. A busca foi realizada em quatro bases de dados (Medline via PubMed, Scopus, ISI Web of Science e BVS - Biblioteca Virtual de Saúde), seguindo os Principais Itens para Relatar Revisões Sistemáticas e Meta-análises. Os artigos obtidos foram carregados no software EndNoteTMe dois revisores independentes selecionaram os estudos e extraíram os dados. Apenas estudos em humanos (relatos de casos, séries de casos, ensaios clínicos) foram incluídos na revisão. De 1.122 estudos potencialmente elegíveis, 83 foram selecionados para análise do artigo completo, e 38 foram incluídos na revisão. Os estudos incluídos foram principalmente relatos de casos (76,3%). Os estudos descreveram um total de 189 dentes submetidos ao REP. Destes, cerca de 54% dos dentes apresentaram algum grau de descoloração. A maioria dos dentes com alteração de cor foi tratada com TAP, principalmente quando combinada com MTA-cinza. Apenas três estudos realizaram o clareamento dental para restaurar a cor dos dentes e nem a técnica de clareamento conseguiu restaurar a cor original das coroas. O uso de materiais alternativos à TAP e ao MTA cinza, como a pasta bi-antibiótica, pasta de Ca(OH)2e MTA branco ou BiodentineTM, reduz a ocorrência de descoloração dentária.

Association between obstructive sleep apnea and alcohol, caffeine and tobacco: A meta-analysis.

The aim of this systematic review was to answer the focused question, "Is there an association between obstructive sleep apnea (OSA) and alcohol, caffeine or tobacco use?" Five electronic databases (Cinahl, Literatura Latth American and Caribbean, PubMed, Scopus, Web of Science) and 3 grey literature (Google Acadêmico, ProQuest, OpenGrey) were searched, as well as search on reference list of included papers and contacts with study authors. Observational studies were included. The Meta-Analysis of Statistics Assessment and Review Instrument (MAStARI) tool assessed the potential risk of bias (RoB) among the studies, while the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach determined the level of evidence. Meta-Analysis was performed with RevMan 5.3 software. Among 3,442 identified studies, 14 were included. Eleven studies were classified as moderate RoB and 3 as high RoB. Meta-analysis showed OSA has no association with tobacco and presented a positive association with alcohol. The odds ratio for OSA increased almost 1.33 times (95% confidence interval [CI]; 1.10-1.62) for alcohol users. There was insufficient published data to evaluate whether OSA is associated with caffeine. The overall quality of evidence ranged from low to very low. OSA was associated with the use of alcohol, however there is not enough evidence to confirm the association with tobacco or caffeine. Due to the very low GRADE level of evidence, caution should be applied when considering these findings.

Incidence of Root Resorption after the Replantation of Avulsed Teeth: A Meta-analysis.

INTRODUCTION: An avulsion injury is a serious trauma to pulp and periodontal tissues. After avulsion and replantation, teeth are at risk of infection and root resorption, which may affect treatment outcome and survival rate. Thus, the purpose of this systematic review was to evaluate the incidence of root resorption after the replantation of avulsed teeth. METHODS: Two reviewers searched 7 electronic databases for observational studies involving human subjects that evaluated the incidence of root resorption after tooth avulsion. Risk of bias (RoB) was evaluated using the Meta-Analysis of Statistics Assessment and Review Instrument, and the quality of available evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation tool. RESULTS: Of the 1507 articles, 23 met the inclusion criteria. A meta-analysis was conducted and showed that the incidence of internal root resorption was 1.2% (95% confidence interval [CI], 0.02-5.50). Regarding external root resorption, the incidence of surface root resorption was 13.3% (95% CI, 6.21-22.62), that of inflammatory root resorption was 23.2% (95% CI, 13.94-34.19), and that of replacement root resorption was 51.0% (95% CI, 40.10-62.00). Two studies presented a high RoB, 16 had a moderate RoB, and 11 had a low RoB. The overall level of evidence identified was very low. CONCLUSIONS: The incidence of root resorption after avulsion and replantation in descending order was replacement root resorption > inflammatory root resorption > surface root resorption > internal root resorption.

Bacterial penetration into filled root canals exposed to different pressures and to the oral environment-in vivo analysis.

OBJECTIVES: The study aims to correlate the depth of bacterial penetration into filled root canals with the time of exposure to the oral environment and different pressures. MATERIALS AND METHODS: One-hundred and twenty-two root canals of male Beagle dog teeth were prepared and filled. The root canals were distributed into three groups, according to the pressure applied: (A) no pressure, (B) 30 kPa, and (C) 60 kPa. Then, the root canals were exposed to the oral environment, establishing sub-groups considering the time intervals of exposure: (1) 45 days and (2) 120 days (n = 17). Sub-groups had positive and negative controls (n = 5). The animals were sacrificed, and the specimens were prepared for histological analysis. RESULTS: There was no significant difference in the bacterial penetration among groups A, B, and C at 45 days (P = 0.903) and 120 days (P = 0.211). No statistically significant difference was found (P = 0.608) between the exposure time intervals. Most of the specimens from experimental groups exposed for 120 days presented moderate inflammatory infiltrate. CONCLUSIONS: Pressures of 30 and 60 kPa did not affect sealing ability of root canal filling. The time of exposure did not influence bacterial penetration, which was limited to the first 4 mm of the root canals exposed for 120 days. CLINICAL RELEVANCE: This animal study demonstrated that disinfection of the first millimeters of root canals could be considered before retreatment of their entire length. However, clinical studies in humans should be conducted before validation of this protocol.

Effect of Milk Renewal on Cell Viability In Vitro at Different Time Frames.

The purpose of this study was to evaluate if the renewal of milk as a storage medium, every 12, 24 and 48 h, is able to increase its ability to maintain human periodontal ligament fibroblasts (PDLF) viability over time. PDLF were soaked in Minimum Essential Medium at 37 °C (MEM-37) (positive control), tap water (Water) (negative control) and in skimmed milk (44 wells) at 5 °C and 20 °C. The skimmed milk was renewed every 12 h (Milk-12), 24 h (Milk-24) and 48 h (Milk-48) in 11 wells of each plate, and the milk in the remaining 11 wells of each plate was maintained in situ (not renewed milk) (NRM). After 24, 48, 72, 96 and 120 h, cell viability was determined by the tetrazolium salt-based colorimetric (MTT) assay. Data were statistically analyzed by Kruskal-Wallis, Scheffé and Mann-Whitney tests (a=5%). At 5 °C, only Milk-48 was significantly better than NRM. At 20 °C, NRM was more effective than Milk-12 and Milk-24 in all time periods. In relation to the temperature (5 °C or 20 °C), renewal of milk at 5 °C was better in maintaining cell viability than the renewal at 20 °C. In conclusion, the renewal of milk was able to increase its ability to maintain cell viability only when performed every 48 h in milk maintained at 5 °C.

Effect of Milk Renewal on Cell Viability In Vitro at Different Time Frames

Abstract The purpose of this study was to evaluate if the renewal of milk as a storage medium, every 12, 24 and 48 h, is able to increase its ability to maintain human periodontal ligament fibroblasts (PDLF) viability over time. PDLF were soaked in Minimum Essential Medium at 37 °C (MEM-37) (positive control), tap water (Water) (negative control) and in skimmed milk (44 wells) at 5 °C and 20 °C. The skimmed milk was renewed every 12 h (Milk-12), 24 h (Milk-24) and 48 h (Milk-48) in 11 wells of each plate, and the milk in the remaining 11 wells of each plate was maintained in situ (not renewed milk) (NRM). After 24, 48, 72, 96 and 120 h, cell viability was determined by the tetrazolium salt-based colorimetric (MTT) assay. Data were statistically analyzed by Kruskal-Wallis, Scheffé and Mann-Whitney tests (a=5%). At 5 °C, only Milk-48 was significantly better than NRM. At 20 °C, NRM was more effective than Milk-12 and Milk-24 in all time periods. In relation to the temperature (5 °C or 20 °C), renewal of milk at 5 °C was better in maintaining cell viability than the renewal at 20 °C. In conclusion, the renewal of milk was able to increase its ability to maintain cell viability only when performed every 48 h in milk maintained at 5 °C.

Resumo O objetivo deste estudo foi avaliar se a renovação do leite, a cada 12, 24 e 48 h, é capaz de aumentar sua capacidade de manter a viabilidade de fibroblastos do ligamento periodontal humano (FLPH) ao longo do tempo. FLPH foram conservados em Meio Essencial Mínimo a 37 °C (MEM-37) (controle positivo), água da torneira (água) (controle negativo) e em leite desnatado (44 poços) a 5 °C e 20 °C. O leite desnatado foi renovado a cada 12 h (leite-12), 24 h (leite-24) e 48 h (leite-48) em 11 poços de cada placa, e em outros 11 poços de cada placa o leite foi deixado in situ (leite não renovado) (LNR). Depois de 24, 48, 72, 96 e 120 h, a viabilidade celular foi determinada pelo ensaio colorimétrico à base de sal tetrazólio (MTT). Os dados foram analisados estatisticamente pelos testes de Kruskal-Wallis, Scheffé e Mann-Whitney (α=5%). A 5 °C, somente o leite-48 foi significantemente melhor do que o LNR. A 20 °C, LNR foi mais efetivo do que o leite-12 e leite-24 em todos os períodos de tempo. Em relação à temperatura (5 °C ou 20 °C), a renovação do leite a 5 °C foi melhor na manutenção da viabilidade celular do que a renovação a 20 °C. Concluindo, a renovação do leite foi capaz de aumentar sua habilidade em manter a viabilidade celular apenas quando realizada a cada 48 h no leite mantido a 5 °C.

Crown discoloration promoted by materials used in regenerative endodontic procedures and effect of dental bleaching: spectrophotometric analysis.

OBJECTIVES: To assess tooth crown's color after intracanal treatment with triple antibiotic paste (TAP) or calcium hydroxide (CH); cervical sealing with glass ionomer cement (GIC) or mineral trioxide aggregate (MTA); and bleaching with carbamide peroxide. MATERIAL AND METHODS: After pulp removal and color spectrophotometer measurement, 50 bovine incisors were divided into 4 experimental groups and one control (untreated). Experiments were performed in phases (Ph). Ph1: TAP (ciprofloxacin, metronidazole, minocycline), TAPM (ciprofloxacin, metronidazole, amoxicillin), DAP (ciprofloxacin, metronidazole), or CH treatment groups. After 1 and 3 days (d); 1, 2, 3 weeks (w); and 1, 2, 3 and 4 months (m), color was measured and medications were removed. Ph2: GIC or MTA cervical sealing, each using half of the specimens from each group. Color was assessed after 1d, 3d; 1w, 2w, 3w; 1m and 2m. Ph3: Two bleaching sessions, each followed by color measurement. Data were analyzed with ANOVA and post-hoc Holm-Sidak method. RESULTS: Ph1: Specimens of TAP group presented higher color alteration (ΔE) mean than those of TAPM group. No significant difference was found among TAP or TAPM and CH, DAP or Control groups. Ph2: cervical sealing materials showed no influence on color alteration. Ph3: Different ΔE means (from different groups), prior to bleaching, became equivalent after one bleaching session. CONCLUSIONS: TAP induces higher color alteration than TAPM; color alteration increases over time; cervical sealing material has no influence on color alteration; and, dental bleaching was able to recover, at least partially, the tooth crown's color.

Crown discoloration promoted by materials used in regenerative endodontic procedures and effect of dental bleaching: spectrophotometric analysis

Abstract Regenerative endodontic procedure (REP) has been proposed as a new approach to treat immature permanent teeth. However, materials used in REP for root canal disinfection or cervical sealing may induce tooth discoloration. Objectives To assess tooth crown’s color after intracanal treatment with triple antibiotic paste (TAP) or calcium hydroxide (CH); cervical sealing with glass ionomer cement (GIC) or mineral trioxide aggregate (MTA); and bleaching with carbamide peroxide. Material and Methods After pulp removal and color spectrophotometer measurement, 50 bovine incisors were divided into 4 experimental groups and one control (untreated). Experiments were performed in phases (Ph). Ph1: TAP (ciprofloxacin, metronidazole, minocycline), TAPM (ciprofloxacin, metronidazole, amoxicillin), DAP (ciprofloxacin, metronidazole), or CH treatment groups. After 1 and 3 days (d); 1, 2, 3 weeks (w); and 1, 2, 3 and 4 months (m), color was measured and medications were removed. Ph2: GIC or MTA cervical sealing, each using half of the specimens from each group. Color was assessed after 1d, 3d; 1w, 2w, 3w; 1m and 2m. Ph3: Two bleaching sessions, each followed by color measurement. Data were analyzed with ANOVA and post-hoc Holm-Sidak method. Results Ph1: Specimens of TAP group presented higher color alteration (ΔE) mean than those of TAPM group. No significant difference was found among TAP or TAPM and CH, DAP or Control groups. Ph2: cervical sealing materials showed no influence on color alteration. Ph3: Different ΔE means (from different groups), prior to bleaching, became equivalent after one bleaching session. Conclusions TAP induces higher color alteration than TAPM; color alteration increases over time; cervical sealing material has no influence on color alteration; and, dental bleaching was able to recover, at least partially, the tooth crown’s color.

Effect of temperature and seven storage media on human periodontal ligament fibroblast viability.

BACKGROUND/AIM: Natural resources, such as coconut water, propolis, and egg whites, have been examined as possible storage media for avulsed teeth. However, there is a lack of research focused on the efficacy of these three products together compared with Hank's balanced salt solution and milk. The aim of this study was to evaluate the capacity of seven storage media to maintain the viability of human periodontal ligament fibroblasts (PDLFs). MATERIAL AND METHODS: PDLFs were kept at 5°C and 20°C, in skimmed milk (SMilk), whole milk (WMilk), recently prepared Hank's balanced salt solution (HBSS), Save-A-Tooth® system's HBSS (Save), natural coconut water (Coconut), Propolis, and egg white (Egg) for 3, 6, 24, 48, 72, 96, and 120 h, through the analysis of tetrazolium salt-based colorimetric (MTT) assay. RESULTS: At 5°C, SMilk and WMilk were better than HBSS in maintaining cell viability, from 24 h onward. At 20°C, HBSS was the best storage medium at 96 and 120 h. At both temperatures, from 6 h onward, Coconut, Propolis and Egg were less effective than SMilk, WMilk, and HBSS. In general, the performance of Coconut, Propolis and Egg were not influenced by storage temperature. However, the lowest temperature undermined the effectiveness of HBSS from 24 h and favored SMilk and WMilk, from 96 and 48 h onward, respectively. Save and water were the worst storage media. CONCLUSION: SMilk was the best storage medium, followed by WMilk and HBSS. Coconut, Propolis, and Egg can be indicated for the conservation of PDLF up to 3 h. The lower temperature (5°C) undermined the effectiveness of HBSS and favored SMilk and WMilk.