Average and Maximum Papilla Heights around Dental Implants in the Anterior Maxillary Region: A Retrospective Clinical Study.

OBJECTIVE: The aim of this study was to determine the average and maximum height of the papilla around maxillary anterior implants in respect of neighboring structures and location of implants. MATERIALS AND METHODS: 92 dental implants from 63 patients were investigated in this study. Those implants were placed in the anterior maxillary region and had been loaded for a minimum of one year. After receiving written consent, clinical data including the height of interproximal papillae adjacent to the tooth/implant/pontic were obtained through clinical observation. The independent t-test or ANOVA, the regression modeling, and generalized estimating equation (GEE) models were used for statistical analysis (p < 0.05). RESULTS: Papilla height was calculated as 2.8 mm (1-5.5 mm) for implant-tooth sites, 2.6 mm (1-4 mm) in implants beside pontics, and 2.5 mm (1-3.5 mm) for implants adjacent to implants. Despite the lack of a significant difference in the mean papilla height in the studied groups, the maximum values of papilla heights were significantly different. CONCLUSIONS: In this study, no significant differences were found in papilla height mean values in relation to neighboring structures or location of implants in the anterior maxilla. However, the maximum values of papilla heights were observed around implants next to natural teeth.

Comparison of Microleakage of Mineral Trioxide Aggregate Apical Plug Applied by the Manual Technique and Indirect Use of Ultrasonic with Different Powers.

STATEMENT OF THE PROBLEM: A mineral trioxide aggregate (MTA) apical plug is commonly applied prior to endodontic treatment of open-apex teeth. However, difficult application and condensation of MTA in the apical region is a drawback of this technique. PURPOSE: This study aimed to compare the microleakage of MTA apical plug applied by the manual technique and indirect use of ultrasonic with different powers. MATERIALS AND METHOD: In this in vitro, experimental study, divergent open apices were created in 48 single-rooted, single-canal teeth using ProFile. The teeth were randomly divided into four experimental groups (n=10). All groups received 5-mm thick MTA apical plug at the apical region using one of the following methods. In group 1, MTA was manually condensed while in groups 2-4, indirect ultrasonic energy with minimum, medium, and maximum power levels was used for MTA plug condensation. After setting of MTA, the apical microleakage of the MTA plug was quantified using the fluid filtration method. Data were analyzed using the Mann-Whitney and Kruskal-Wallis tests (p< 0.05). RESULTS: Significant differences were noted in microleakage of MTA plug between the manual group and ultrasonic groups with medium (p= 0.043) and maximum (p= 0.029) power levels. No significant difference was noted in microleakage of other groups (p> 0.05). CONCLUSION: Considering the current results, it seems that application of MTA with indirect ultrasonic energy at medium or high power level would decrease the microleakage of MTA plug in open-apex root canals.

The effect of dynamic loading on bacterial microleakage of the dental implant fixture-abutment interface: An in vitro study.

Aim: Bacterial micro leakage at implant-abutment interface under functional loading is an important factor, may lead to crestal bone loss and affect the long term success of dental implants. Due to the limited studies about the implant systems with a connection of Slip joint design, this study aimed to evaluate the effect of dynamic loading on bacterial leakage at the implant-abutment interface with slip joint connection. Settings and Design: In vitro- comparative study. Materials and Methods: A total of 20 implants and abutments with slip joint connections (Tapered Screw-Vent, 3.7 mm ×10 mm, Zimmer Dental, USA) was examined and depends on using functional loading were divided into two groups; loaded and unloaded. Initially, 10 µl of Brain Heart Infusion (BHI) culture broth was pipetted to the internal lumen of each implant, then the abutments were tightened to the fixtures and crowns were cemented. In the unloaded group, samples were immersed in E-Coli suspension for 5 days. In the loaded group, samples were immersed in microbial suspension under 500000 cycles using a cyclic load device. Following disconnection of fixtures and abutments, microbial samples were taken from the internal lumen of implants and colonies were counted. Data were analyzed using. Statistical Analysis Used: Mann-Whitney statistical test, SPSS version 24. Results: The mean rate of micro leakage in unloaded and loaded groups was 4000 CFU/ml and 27000 ± 31640 CFU/ml respectively. Bacterial colonies grew in 10% of unloaded samples and 50% of loaded samples. This difference was statistically significant. (P < 0.05). Conclusions: Microbial micro leakage at the implant-abutment interface with slip joint design increased significantly after functional loading.

Flexural strength of polyether ether ketone high-performance polyether in comparison with base metal alloy and zirconia ceramic / Resistencia a la flexión del poliéter éter cetona poliéter de alto rendimiento en comparación con la aleación de metal base y la cerámica de circonio

Optimal flexural strength is a critical prerequisite for prosthetic frameworks. This study aimed to assess the flexural strength of polyether ether ketone (PEEK) polymer compared to a base metal alloy and high-strength Zirconia ceramic commonly used in prosthodontic treatments. Materials and Methods: In this in vitro, experimental study, 10 bar-shaped samples measuring 18×5×2mm were fabricated of each the PEEK polymer, nickel-chromium base metal alloy and zirconia ceramic. Half of the samples in each group were subjected to 5000 thermal cycles between 5°C - 55°C with 20 seconds of dwell time and 20 seconds of transfer time to simulate oral conditions. All samples then underwent three-point bending test. Two-way ANOVA followed by Tukey's test were applied to compare the mean flexural strength of the groups with and without thermocycling at 0.05 level of significance. Results: The flexural strength of base metal alloy, Zirconia and PEEK was 1387.70±45.50 MPa, 895.13±13.99 MPa and 192.10±5.37 MPa, respectively. The difference was significant among the groups (p<0.001). Thermocycling had no significant effect on the flexural strength of samples in any group (p=0.306). Conclusion: PEEK high-performance polymer had a lower flexural strength than base metal alloy and Zirconia ceramic, and its flexural strength was not affected by thermocycling. PEEK seems to be able to resist masticatory forces in the oral cavity pending further in vitro and clinical studies.

La resistencia a la flexión óptima es un requisito previo crítico para los marcos protésicos. Este estudio tuvo como objetivo evaluar la resistencia a la flexión del polímero de poliéter éter cetona (PEEK) en comparación con una aleación de metal base y cerámica de Zirconia de alta resistencia comúnmente utilizada en tratamientos de prostodoncia. Materiales and Métodos: En este estudio experimentalin vitro, se fabricaron 10 muestras en forma de barra de 18 × 5 × 2mm de cada polímero PEEK, aleación de metal base de níquel-cromo y cerámica de circonio. La mitad de las muestras en cada grupo fueron sometidas a 5000 ciclos térmicos entre 5°C - 55°C con 20 segundos de tiempo de permanencia y 20 segundos de tiempo de transferencia para simular condiciones orales. Todas las muestras se sometieron a una prueba de flexión de tres puntos. Se aplicó ANOVA bidireccional seguido de la prueba de Tukey para comparar la resistencia a la flexión media de los grupos con y sin termociclado a un nivel de significancia de 0.05. Resultados: La resistencia a la flexión de la aleación de metal base, Zirconia y PEEK fue de 1387,70 ± 45,50 MPa; 895,13 ± 13,99 MPa y 192.10 ± 5,37 MPa, respectivamente. La diferencia fue significativa entre los grupos (p<0,001). El termociclado no tuvo un efecto significativo sobre la resistencia a la flexión de las muestras en ningún grupo (p=0,306).Conclusión:El polímero de alto rendimiento PEEK tiene una resistencia a la flexión más baja que la aleación de metal base y la cerámica de circonio, y su resistencia a la flexión no se vio afectada por el termociclado. PEEK parece ser capaz de resistir las fuerzas masticatorias en la cavidad oral, con la necesidad de más estudios in vitroy clínicos.

Evaluation of Impacting Factors on Facial Bone Thickness in the Anterior Maxillary Region.

BACKGROUND: The goal of the current study was to measure the width of the labial alveolar bone of the overlying maxillary anterior teeth, based on cone-beam computed tomography (CBCT) images, and the distance between cementoenamel junction (CEJ) and bone crest in adult patients. METHODS: A cross-sectional study was performed using a sample of 132 tomographic scans. Intact maxillary anterior with healthy periodontium and teeth was randomly selected and afterwards assessed by 2 calibrated and independent reviewers. RESULT: The average bone thickness at 2 mm from the CEJ of the maxillary right central incisors was 0.63 ±â€Š0.69 mm and over the maxillary left central incisors was 0.59 ±â€Š0.71 mm. Moreover on the right and left lateral maxillary incisors, the crestal bone width averaged 0.64 ±â€Š0.81 and 0.61 ±â€Š0.7 mm, respectively. Concerning the maxillary canine region on both sides, the crestal bone thickness averaged 0.72 ±â€Š0.9 and 0.66 ±â€Š0.69 mm, in the maxillary right and left the canine regions, respectively. Furthermore, according to the gender and systemic disease, there were some recognizable differences in the facial bone thickness between the left and the right side. CONCLUSIONS: The current study has advocated the outcome of a mostly thin buccal bone overlying the maxillary anterior teeth; hence, clinicians should always consider the thickness of the facial cortical plate of the extraction site and the positioning of the implant placement in the socket.

Clinical Comparison of Full and Partial Double Pedicle Flaps with Connective Tissue Grafts for Treatment of Gingival Recession.

STATEMENT OF THE PROBLEM: Gingival recession has been considered as the most challenging issue in the field of periodontal plastic surgery. PURPOSE: The purpose of this study was to evaluate the clinical efficacy of root coverage procedures by using partial thickness double pedicle graft and compare it with full thickness double pedicle graft. MATERIALS AND METHOD: Eight patients, aged 15 to 58 years including 6 females and 2 males with 20 paired (mirror image) defects with class I and II gingival recession were randomly assigned into two groups. Clinical parameters such as recession depth, recession width, clinical attachment level, probing depth, and width of keratinized tissue were measured at the baseline and 6 months post-surgery. A mucosal double papillary flap was elevated and the respective root was thoroughly planed. The connective tissue graft was harvested from the palate, and then adapted over the root. The pedicle flap was secured over the connective tissue graft and sutured. The surgical technique was similar in the control group except for the prepared double pedicle graft which was full thickness. RESULTS: The mean root coverage was 88.14% (2.83 mm) in the test group and 85.7% (2.75 mm) in the control group. No statistical differences were found in the mean reduction of vertical recession, width of recession, or probing depth between the test and control groups. In both procedures, the width of keratinized tissue increased after three months and the difference between the two groups was not statistically significant in this respect. CONCLUSION: Connective tissue with partial and full thickness double pedicle grafts can be successfully used for treatment of marginal gingival recession.

Bone-added periodontal plastic surgery: a new approach in esthetic dentistry.

This article proposes a combined technique including bone grafting, connective tissue graft, and coronally advanced flap to create some space for simultaneous bone regrowth and root coverage. A 23 year-old female was referred to our private clinic with a severe class II Miller recession and lack of attached gingiva. The suggested treatment plan comprised of root coverage combined with xenograft bone particles. The grafted area healed well and full coverage was achieved at 12-month follow-up visit. Bone-added periodontal plastic surgery can be considered as a practical procedure for management of deep gingival recession without buccal bone plate.

Interleukin 17 receptor gene polymorphism in periimplantitis and chronic periodontitis.

Gene polymorphism of cytokines influencing their function has been known as a contributing factor in the pathogenesis of inflammatory diseases of the tooth and implant supporting tissues. The aim of this study was to investigate the association of IL-17R gene polymorphism (rs879576) with chronic periodontitis and periimplantitis in an Iranian population. 73 patients with chronic periodontitis, 37 patients with periimplantitis and 83 periodontally healthy patients were enrolled in this study. 5cc blood was obtained from each subject's arm vein and transferred to tubes containing EDTA. Genomic DNA was extracted using Miller's Salting Out technique. The DNA was transferred into 96 division plates, transported to Kbioscience Institute in United Kingdom and analyzed using the Kbioscience Competitive Allele Specific PCR (KASP) technique. Chi-square and Kruskal Wallis tests were used to analyze differences in the expression of genotypes and frequency of alleles in disease and control groups (P-Value less than 0.05 was considered statistically significant). There were no significant differences between periodontitis, periimplantitis with AA, GG, GA genotype of IL-17R gene (P=0.8239). Also comparison of frequency of alleles in SNP rs879576 of IL-17R gene between the chronic periodontitis group and periimplantitis group did not revealed statistically significant differences (P=0.8239). The enigma of IL-17 and its polymorphism-role in periodontitis and periimplantitis is yet to be investigated more carefully throughout further research but this article demonstrates that polymorphism of IL-17R plays no significant role in incidence of chronic periodontitis and Periimplantitis.

IL-17 gene polymorphism is associated with chronic periodontitis and peri-implantitis in Iranian patients: a cross-sectional study.

Periodontal disease (PD) and peri-implantitis (PI) are characterized by an immune response leading to destructive inflammation. The prominent impact of genetic factors on periodontitis has been previously evaluated and IL-17 has found to play a critical role in this process. This cytokine has a controversial behavior. This study aimed at finding out whether the polymorphism of this cytokine plays a significant role in chronic periodontitis (CP) and PI or it is just a pro-inflammatory regulatory cytokine. Fresh human blood samples were obtained and three main genotypes were traced carefully. The samples were transferred into 96-well plates and sent to KBioscience Institute in the United Kingdom for genotyping the polymorphism using Competitive Allele Specific PCR (KASP) technique. SPSS version19 software and chi-square and Kruskal-Wallis tests were used for statistical differences considering p-value less than 0.05. A significant difference was detected between the three groups in terms of specific SNP studied in this experiment (P = 0.00). The CC genotype of IL17 polymorphism (rs10484879) may contribute to the pathogenesis of peri-implantitis and periodontitis. The association of IL-17 polymorphism with PI and CP is a promising finding that may help in future similar studies on other ethnicities and larger study populations.

Local concentration of systemic amoxicillin and metronidazole in healthy and inflamed gingiva: a comparative in vivo study.

BACKGROUND: One of the most recommended methods of systemic antibiotic administration in periodontics is the combination of amoxicillin and metronidazole, which has great inhibitory effect on periodontal pathogens. The aim of this study is to determine the local concentrations of these drugs in gingiva and compare its distribution in healthy and inflamed tissues. METHODS: The study population was selected from patients referred to our department. Fifteen subjects were referred for crown lengthening, and another 15 subjects required flap surgery because of severe periodontitis. All 30 patients received three doses of amoxicillin 500 mg plus metronidazole 250 mg before surgery. Tissue samples were gathered during surgery, and chemotherapy was continued for 7 days with 8-h intervals. After 7 days, during the second appointment, the next samples were collected. Samples were sent to the laboratory to determine the drug concentration with the use of high-performance liquid chromatography. RESULTS: Amoxicillin concentration in healthy gingival tissue was not detectable. The concentrations after 24 h and 7 days of administration were 25.9±4.1 and 124.8±18 µg/mL, respectively. The values for metronidazole were 28.86±1.7, 1.70±0.3, and 36.0±1.5 µg/mL. CONCLUSIONS: The combination of systemic amoxicillin and metronidazole for 7 days has sufficient gingival connective tissue concentration much more than the minimum inhibitory concentration in healthy and inflamed tissue.