Clinical efficacy of soft-tissue augmentation on tissue preservation at immediate implant sites: A randomized controlled trial.

AIM: This randomized controlled trial aimed to investigate the efficacy of soft-tissue augmentation (STA) with a subepithelial connective tissue graft (SCTG) or an acellular dermal matrix (ADM) on reducing tissue alterations at an immediate implant site. MATERIALS AND METHODS: This trial had three groups: (i) immediate implant with SCTG (ICT group); (ii) immediate implant with ADM (IAD group); (iii) immediate implant without STA (control group). Forty-six patients were randomly assigned to each group. Implants were placed at the maxillary anterior or premolar areas and restored after the 6-month visit. Clinical outcomes, including buccal soft-tissue contour, peri-implant mucosal level, soft-tissue thickness and keratinized tissue width, were measured at baseline and at 3-, 6- and 12-month follow-up visits. Radiographic bone levels were measured at baseline and at 6- and 12-month follow-up visits. Patient-reported outcomes were also collected. RESULTS: STA procedures increased peri-implant mucosal thickness and maintained buccal soft-tissue contours. Compared to the control group, STA groups did not prevent peri-implant mucosal recession or interproximal bone resorption. Generally, no significant differences in clinical outcomes were detected between the ICT and IAD groups. Most patients were highly satisfied with the immediate implant procedure and outcomes without significant differences between groups. CONCLUSIONS: STA at immediate implant sites enhanced soft-tissue thickness and maintained soft-tissue contours but did not prevent peri-implant mucosal recession or interproximal bone resorption. Long-term follow-up should be performed since these results were reported for only up to 1 year.

Altered human alveolar bone gene expression in type 2 diabetes-A cross-sectional study.

OBJECTIVE: The objective of this cross-sectional study is to investigate alveolar bone gene expression in health and diabetes through ribonucleic acid (RNA) sequencing and bioinformatics analysis. BACKGROUND: It is relatively unknown how type 2 diabetes modulates gene expression in alveolar bone in humans. Clinical concern regarding increased implant failure rate in patients with diabetes has been discussed in the literature. Previous studies in animal models and humans have suggested an imbalance between the genes regulating bone formation with data suggesting bone resorption in diabetes. However, there is lack of data regarding a comprehensive gene expression from human alveolar bone in diabetes. METHODS: Alveolar bone was collected from healthy and type 2 diabetic subjects undergoing periodontal and implant surgeries. The homogenized RNA sample was then extracted and analyzed for quantity and quality. RNA samples were further purified using ribosomal RNA depletion technique and processed for RNA sequencing and analysis. Expression levels for mRNAs were performed by calculating FPKM ([total_exon_fragments/mapped reads (millions) × exon length (kB)]), and differentially expressed mRNAs were selected with log2 (fold change) >1 or log2 (fold change) ≤1 and with a parametric F test comparing nested linear models. RESULTS: Eighteen bone samples (10 healthy, 8 patients with diabetes) were analyzed for gene expression. The mean age and HbA1c% of healthy versus diabetic subjects were as follows: age (55.3 ± 17.5 vs 63.9 ± 8.7 years) and HbA1c% (5.6 ± 0.29 vs 7.3 ± 2.4), respectively. Sequencing analysis showed that expression of genes that regulate bone turnover like TGFB1, LTBP4, IGF1, BMP2, BMP4, BMP6, SMAD1, RUNX2, MCSF, and THRA was significantly downregulated in diabetes samples compared with healthy controls with overall reduced expression of genes in the bone regulation pathway in patients with diabetes. Bioinformatics analysis for the altered genes highlighted several pathways related to bone homeostasis and inflammation in diabetes. Periodontitis did not affect the gene expression pattern based on diabetes status. CONCLUSIONS: Altered expression of genes due to downregulation of certain pathways that are involved in bone turnover and inflammation suggests that overall wound healing and bone homeostasis may be compromised in type 2 diabetes.

The ability to screw-retain single implant-supported restorations in the anterior maxilla: A CBCT analysis.

STATEMENT OF PROBLEM: Evidence to validate the routine use of angled screw-channel abutments in the anterior maxilla is sparse. If properly planned, they might provide surgical and prosthetic benefits. PURPOSE: The purpose of this observational study was to determine the prevalence of digitally placed implants in the anterior maxilla that would allow screw-retained implant-supported restorations with either a straight or an angled screw-channel abutment. MATERIAL AND METHODS: Two hundred cone beam computed tomography (CBCT) scans met the inclusion criteria for retrospective analysis and digital implant planning. Virtual implants were planned for randomly selected anterior maxillary teeth by using the anatomic crown and root position. Virtual abutments of varying angulation were attached to the implants to determine the ability to screw retain a restoration with either a straight or an angled screw-channel abutment. RESULTS: One hundred fifty-two (76%) sites required an angled screw-channel abutment to enable screw retention. Forty-eight (24%) sites allowed screw retention with a straight abutment. The percentage of implants requiring angled or straight abutments varied significantly among anterior teeth (P<.005). One hundred nine (71.7%) angled screw-channel abutment sites required a 5-degree abutment, 41 (26.9%) required a 10-degree abutment, and 2 (1.3%) required a 15-degree abutment. Among the anterior teeth, lateral incisors presented a greater need for angled screw-channel abutments. None of the implants in the present study needed cement-retained restorations. CONCLUSIONS: Angled abutments allowed for screw-retained restorations on digitally planned implants in the anterior maxilla. The required angular correction to a screw-retained restoration was ≤15 degrees. Screw-retained restorations were frequently achievable (76%) with the use of angled screw-channel abutments or with straight abutments (24%), and lateral incisors presented a greater need for angled screw-channel abutments.

Cone-Beam Computed Tomography Analysis of the Prevalence, Length, and Passage of the Anterior Loop of the Mandibular Canal.

When placing implants in the anterior mandible, it is important to avoid damaging the mandibular nerve and its terminal extensions. The objective of this study was to determine the prevalence, length, and passage of the anterior loop of the mandibular canal, as well as the quantity of alveolar bone that is coronal to the canal, to help with implant placement in the anterior mandible. Cone-beam computerized tomography (CBCT) scans of 124 patients with 248 hemi-sections were evaluated. Anterior loop prevalence was determined using reconstructed panoramic and cross-sectional views; length was measured as the distance between the most mesial aspect of the mental foramen to the most mesial aspect of the anterior loop on cross-sectional views. The bucco-lingual position of the anterior loop inside the mandible and the apico-coronal dimensions of the alveolar bone above it were measured on cross-sectional views to determine the passage of the anterior loop and the bone available coronally, respectively. The effects of sex, age, side, and dentate status on the prevalence and length of the anterior loop were analyzed statistically. Prevalence of the anterior loop at the patient and hemi-section levels was 25% and 24%, respectively, and its median length was 1.63 mm (range, 0.52-3.92 mm). The anterior loop was apical to the mental foramen and mostly located within the buccal or middle one-third of the alveolar ridge, with an average height of coronal alveolar bone of 17.12 mm. Sex, age, side, and dentate status did not affect anterior loop prevalence and length. In conclusion, because of great variation, a case-by-case CBCT evaluation of the anterior loop is necessary before placing implants in the anterior mandible.

Anterior maxilla alveolar ridge dimension and morphology measurement by cone beam computerized tomography (CBCT) for immediate implant treatment planning.

BACKGROUND: Implants have been widely used to restore missing teeth. Limited information on applied anatomy at the anterior maxilla compromises the clinical outcome for implant placement in this region. In the current study, Cone Beam Computerized Tomography (CBCT) was used to measure alveolar ridge and buccal undercut dimension at the anterior maxilla to help develop treatment planning for immediate implant placement. METHODS: CBCT scans were screened to include 51 subjects with full dentition at right maxilla. Measurements were taken at the cross sectional views in the middle of the maxillary right central incisor, lateral incisor, and canine regions. Alveolar height was measured from the alveolar crest to floor of nasal fossa. Alveolar width was measured from the buccal to palatal cortical plate at the coronal, middle, and apical third of the distance from the alveolar crest to floor of the nasal fossa. Buccal undercut location was measured from where the buccal cortical plate started dipping to a line extending at the alveolar crest that was perpendicular to the long axis of the alveolar ridge. The buccal undercut depth was measured from the deepest point of the undercut at the buccal plate to a line tangent to the buccal plate paralleling the long axis of ridge. RESULTS: Alveolar width increased from coronal to apical direction for each tooth. Mean alveolar widths (mm) were: central incisor, 9.55; lateral incisor, 8.30; canine, 9.62. The lateral incisor had a significantly smaller alveolar width than the other anterior teeth. No significant difference in ridge height was noted among the teeth. Undercut locations from the alveolar crest (mm) were: central incisor, 5.84; lateral incisor, 3.59; canine, 5.11. Undercut depths (mm) were: central incisor, 0.76; lateral incisor, 0.87; canine, 0.73. The percentages of teeth with buccal undercuts were: central incisor, 41%, lateral incisor, 77%, and canine 33%. Male demonstrate significant larger ridge width compared with females for all three teeth. CONCLUSIONS: At anterior maxilla, the lateral incisor has the thinnest alveolar bone, and most frequently exhibits a buccal undercut which is the closest to alveolar ridge compared with other maxillary anterior teeth.

The effect of periodontal therapy on glycaemic control in a Hispanic population with type 2 diabetes: a randomized controlled trial.

OBJECTIVE: In the Mexican-American population, the prevalence of Type 2 diabetes mellitus (T2DM) is as high as 50% of the population. This randomized controlled clinical trial was designed to elucidate how treatment of periodontal disease affects HbA1c values in this population. MATERIALS AND METHODS: One hundred and fifty-four T2DM patients with periodontal disease were enrolled in the study. The test group was treated with scaling and root planing (SRP); the control group received oral hygiene instructions. At baseline and 4-6 weeks after therapy, a complete periodontal examination was performed. Blood was collected at baseline and 4 months later for HbA1c levels. RESULTS: One hundred and twenty-six individuals completed the study. Baseline mean ± SD HbA1c for the test and control groups were 9.0 ± 2.3% and 8.4 ± 2.0% respectively. Non-significant difference in HbA1c reductions (0.6 ± 2.1% and 0.3 ± 1.7%) was found between test and control groups at 4 months. Comparisons of the periodontal clinical parameters between the test and control groups found significant differences with improved results in the test subjects. CONCLUSIONS: No statistically significant differences were found in the changes of HbA1c levels between test and control groups. Non-surgical periodontal therapy improved the magnitude of change in periodontal parameters as compared to the control subjects. ClinicalTrials.gov Identifier: NCT01128374.

The Significance of Mylohyoid Muscle Release (MMR) in the Vertical and Horizontal Ridge Augmentation Surgeries; Clinical and Human Cadaver Analyses of the Techniques.

(1) Background: Ridge augmentations either horizontal (HRA) or vertical (VRA) in the posterior mandible are very challenging regenerative procedures. To attain and retain tension-free primary closure, buccal periosteal and mylohyoid muscle releases should be performed. The purpose of the present study was to review, analyze and discuss the three different techniques for the mylohyoid muscle release (MMR) in VRA and HRA surgeries on a clinical and human cadaver level. (2) Presentation of the techniques: Three different techniques are described in the literature regarding the lingual flap management: (i) the finger sweep technique (FST), (ii) the release of the mylohyoid muscle attachment on the lingual flap (MMALF), and (iii) the mylohyoid preservation technique (MPT) in three key anatomical zones. All three techniques, even though they use a different approach, can achieve similar amount of horizontal and vertical mylohyoid muscle release although MPT showed statistically significant higher flap advancement. The human cadaver analyses revealed that all three techniques are considered safe since they do not approximate vital anatomical structures. (3) Conclusions: All three techniques are considered safe, but they are not free of limitations or complications; therefore, they should be performed only by highly experienced and trained clinicians. MPT achieved statistically significant higher flap advancement.

Preclinical teaching of periodontal surgical concepts using common instructional models: A comparative assessment.

OBJECTIVES: Some commonly used models utilized for teaching periodontal surgical techniques to dental students include pig mandible and periodontal typodonts. Currently, no study compares the learning and teaching outcomes following the use of one model to the other. This study is aimed at evaluating the effectiveness of the preclinical laboratory component on student understanding of concepts taught in the periodontal surgical course and assessing students' and faculty members' satisfaction with the instructional models. METHODS: As part of the surgical periodontics course, 98 students took the final exam, with eighty students participating in only the pig mandible session and twenty-three students participating in both the pig jaw mandible and an additional session utilizing periodontal typodonts under the supervision of ten periodontal faculty members. Examination scores of students attending or not attending the laboratory session were analyzed by a two-sample t-test. A questionnaire evaluating the effectiveness of both models was given to faculty members and students who participated in both laboratory sessions. These results were analyzed by paired t-test. RESULTS: Participation in the laboratory sessions did not significantly impact the final exam scores (p = 0.722). Students who had better didactic performance in the course performed better in the final exam, irrespective of laboratory participation. Both students and faculty members preferred typodont to the pig mandibles in learning or teaching periodontal surgical concepts, but both felt gaining flap management and flap refection experience to be better with the pig mandible model without statistical significance (p = 0.119 and p = 0.070, respectively). CONCLUSION: Within the limitations of this study, we can conclude that laboratory sessions did not significantly improve student performance on the exam. Students and faculty members generally gave positive feedback on both instructional models. Periodontal typodont could be an alternative model for teaching dental students, periodontal surgical concepts.

The Associations of Cardiometabolic and Dietary Variables with Clinical Periodontitis in Adults with and without Type 2 Diabetes: A Cross-Sectional Study.

Periodontitis is a commonly occurring inflammatory oral disease affecting a large proportion of global and US adults and is characterized by the destruction of the tooth-supporting apparatus. Its etiology is multifactorial, and type 2 diabetes and diet play critical roles in its remission and progression. However, few studies have addressed nutritional and serum vitamin D status in adults with periodontitis in the presence of diabetes. A cross-sectional study (n = 78), and a sub-set of age- and BMI-matched case-control studies (n = 50), were conducted to examine differences in dietary and cardiometabolic variables, and serum vitamin D in adults with periodontitis with or without diabetes. Participants provided fasting blood samples and 24-h diet recalls on at least two different days. Data on health history, body weight, height, nutritional habits, and clinical features of periodontitis were also collected. The Mann-Whitney U Test (with exact p-value estimation by Monte Carlo simulation) was used to examine differences by diabetes status in continuous and ordinal variables. Results revealed significantly lower serum vitamin D, and dietary intake of fruits, vegetables, dairy, vitamins A and C in adults with periodontitis with vs. without diabetes in the sub-study (all p < 0.05). In the overall sample, adults with diabetes presented with higher caries risk measures and lower numbers of teeth than those without diabetes; plaque and bleeding scores did not differ by diabetes status. Finally, a significant associations of food habits was observed, especially consuming protein-rich foods twice a day with a lower bleeding score, and daily consumption of fried or fast foods with a fewer number of teeth present (all p < 0.05). The present findings show significant dietary and serum vitamin D inadequacies among adults with periodontitis, and diabetes further aggravates the observed malnourishment and oral health.

Influences of race/ethnicity in periodontal treatment response and bacterial distribution, a cohort pilot study.

Objectives: Periodontitis disproportionately affects different racial and ethnic populations. We have previously reported the higher levels of Porphyromonas gingivalis and lower ratios of Streptococcus cristatus to P. gingivalis may contribute to periodontal health disparities. This prospective cohort study was designed to investigate if ethnic/racial groups responded differently to non-surgical periodontal treatment and if the treatment outcomes correlated to the bacterial distribution in patients with periodontitis before treatment. Methods: This prospective cohort pilot study was carried out in an academic setting, at the School of Dentistry, University of Texas Health Science Center at Houston. Dental plaque was collected from a total of 75 African Americans, Caucasians and Hispanics periodontitis patients in a 3-year period. Quantitation of P. gingivalis and S. cristatus was carried out using qPCR. Clinical parameters including probing depths and clinical attachment levels were determined before and after nonsurgical treatment. Data were analyzed using one-way ANOVA, the Kruskal-Wallis test, the paired samples t-test and the chi-square test. Results: The gains in clinical attachment levels after treatment significantly differed amongst the 3 groups-Caucasians responded most favorably, followed by African-Americans, lastly Hispanics, while numbers of P. gingivalis were highest in Hispanics, followed by African-Americans, and lowest in Caucasians (p = 0.015). However, no statistical differences were found in the numbers of S. cristatus amongst the 3 groups. Conclusion: Differential response to nonsurgical periodontal treatment and distribution of P. gingivalis are present in different ethnic/racial groups with periodontitis.

Vertical Ridge Augmentation Around Dental Implants With the Use of a Dense PTFE Membrane to Correct Previously Failed Augmentations.

INTRODUCTION: Vertical ridge augmentation (VRA) is one of the most challenging procedures. This is the first case report to show 2-5 mm VRA after two unsuccessful GBRs around previously placed dental implants, with the use of an exposed d-PTFE membrane. CASE PRESENTATION: A 79-year-old ASA II Caucasian male presented after two previous GBR procedures on the LLQ. The second attempt left the site with two exposed implants, scar tissue, no keratinized tissue and lack of vestibular depth. VRA was attempted with the use of cortical perforations, tenting screws, dense PTFE membrane and a 50:50 mixture of anorganic bovine bone matrix and mineralized allograft. The site was left to heal in a secondary intention, leaving the d-PTFE membrane exposed. The membrane was removed 4 weeks postoperatively. The healing abutments were placed, the tenting screws were removed, and the site was allowed to heal for more than seven months. Radiographically, VRA was achieved ranging from 2 to 5 mm. A vestibuloplasty was performed using a diode laser and subsequent flap dissection. Four months after the vestibuloplasty, the tissue surrounding the implants showed adequate keratinization, and an elongated vestibular depth. In addition, in both implants, the emergence profile buccal and lingual was more than 3 mm and the patient was referred to his prosthodontist for the fabrication of the final restorations. CONCLUSIONS: VRA around dental implants was achieved with the use of a nonresorbable dense PTFE membrane, which was left exposed to heal in a secondary intention, tenting screws and a combination grafting technique to correct two previously failed GBRs.

Temperature Changes during Implant Osteotomy Preparations in Fresh Human Cadaver Tibiae, Comparing Straight with Tapered Drills.

The success of osseointegration depends on many factors. With temperatures beyond a 47 °C threshold over 1 min, bone survival may be impaired. The purpose of the study was to evaluate, in fresh human cadaver tibiae, the temperature changes during osteotomy preparations using two straight and two tapered implant systems' drills, external irrigation, and varying revolutions per minute (RPM). The tibiae from a fresh female cadaver were harvested bilaterally. Two tapered and two straight design drills were assessed. Two-hundred and forty osteotomies were prepared at 6 mm depth following the drill sequence of the manufacturers' protocol for each drilling speed. Difference in temperature (ΔΤ) was calculated by subtracting the baseline from the maximum temperature (ΔT = Tmax - Tbase). Drill design and drill diameter, as independent variables or synergistically, had a significant effect on ΔΤ. Tapered drills: As the drill diameter increased, ΔΤ increased at all RPM. Straight drills: As the drill diameter increased, ΔΤ remained constant or slightly decreased at all RPM. Drill diameter and design had a significant effect on ΔΤ in human tibiae, which never exceeded the critical threshold of 47 °C. Tapered drills caused significantly greater heat production compared to straight drills.

A long-term retrospective analysis of single tooth implants and endodontic therapies in a university setting.

BACKGROUND: This study aimed to compare survival of single tooth implants (SI) to teeth receiving initial endodontic treatment (IET), non-surgical (NET), and surgical endodontic retreatments (SET). The secondary aim was to determine success rate and identify factors associated with the survival and success of implant and endodontic treatments. METHODS: A retrospective cohort study using electronic health records (January 1st, 1995 to April 30th, 2017) was conducted. Every case that qualified for the study in SI (n = 321), NET (n = 211), and SET (n = 79) was included and cases in IET (n = 642) were selected at random and with a 2 to 1 case ratio to SI for data extraction efficiency. Statistical analyses were conducted to compare survival rates and estimate success rates between the four groups adjusting for confounders. RESULTS: The 3 year survival rates for SI, IET, NET, and SET were 99.0%, 92.1%, 90.5%, and 89.5% while the 5 year survival rates for SI, IET, NET, and SET were 99.0%, 87.6%, 84.4%, and 81.1%, respectively. Generally, the SI group had the highest survival rate and the SET group had the lowest survival rate. Short implants (≤8 mm) were significantly associated with implant failure (P < 0.01). Teeth with composite restoration had lower survival rates in IET and NET than other restorations (P < 0.01 and < 0.01). CONCLUSION: Within the limitations of this study, single tooth implants and the endodontic treatments yielded predictable survival and success in the short term but the survival and success rates in endodontic treatments dropped more rapidly than single tooth implants during the longer follow-up period.

Temperature Changes during Implant Osteotomy Preparations in Human Cadaver Tibiae Comparing MIS® Straight Drills with Densah® Burs.

(1) Background: Several studies showed a sustained temperature of 47 °C or 50 °C for one minute resulted in vascular stasis and bone resorption with only limited bone regrowth over a 3-4-week healing period. The purpose of the present study was to evaluate the temperature changes (ΔΤ) that occur during the preparation of dental implant osteotomies using MIS® straight drills versus Densah® burs in a clockwise (cutting) drilling protocol. (2) Methods: Two hundred forty (240) osteotomies of two different systems' drills were prepared at 6 mm depth at 800, 1000, and 1200 revolutions per minute (RPM), in fresh, unembalmed tibiae, obtained by a female cadaver. ΔΤ was calculated by subtracting the baseline temperature on the tibial surface, from the maximum temperature-inside the osteotomy (ΔT = Tmax - Tbase). The variables were evaluated both for their individual and for their synergistic effect on ΔΤ with the use of one-, two-, three- and four-way interactions; (3) Results: An independent and a three-way interaction (drill design, drill width, and RPM) was found in all three RPM for the Densah® burs and at 1000 RPM for the MIS® straight drills. As Densah® burs diameter increased, ΔΤ decreased. The aforementioned pattern was seen only at 1000 RPM for the MIS® straight drills. The usage of drills 20 times more than the implant manufacturers' recommendation did not significantly affect the ΔΤ. A stereoscopic examination of the specimens confirmed the findings. (4) Conclusions: The independent and synergistic effect of drills' diameter, design and RPM had a significant effect on ΔΤ in human tibiae, which never exceeded the critical threshold of 47 °C.

Vertical ridge augmentation (VRA) with the use of a cross-linked resorbable membrane, tenting screws, and a combination grafting technique: a report of three cases.

OBJECTIVE: The purpose of the present study was to present vertical ridge augmentation (VRA) with the use of cross-linked resorbable membrane, tenting screws, and a combination grafting technique. REPORT: Three cases are presented. Case 1: A 67-year-old ASA II patient required VRA at the areas of the mandibular left second premolar and first molar. Flap management was performed with the use of periosteal release on the buccal aspect and 23 mm of mylohyoid muscle release on the lingual aspect. VRA was completed with the use of four self-tapping tenting screws, and 1:1 mix of anorganic bovine bone matrix (ABBM) and particulate mineralized bone allograft. A cross-linked resorbable membrane was placed over the buccal and lingual aspect, and a double line of suturing was performed to secure the tension-free closure. Twelve months postoperatively, 4 mm of VRA was confirmed with CBCT. Two implants were placed with >35 Ncm primary stability. Case 2: A 64-year-old ASA I patient required VRA at the area of the maxillary first premolar. Flap management was performed with the use of periosteal release on the buccal aspect and VRA was performed with a 9-mm self-tapping screw, 1:1 mix of ABBM and particulate mineralized bone allograft, a cross-linked resorbable membrane, and a double line of suturing. Twelve months postoperatively, VRA of 6.2 mm on the buccal aspect and 7.9 mm on the lingual aspect were confirmed with CBCT. An implant was placed with > 35 Ncm primary stability in combination with horizontal ridge augmentation. Case 3: A 70-year-old ASA II patient required horizontal and VRA at the area of the mandibular left canine. Following extraction, a lateral pedicle sliding flap was completed to enhance the soft tissue volume of the site. After 6 weeks, flap management was performed with the use of buccal periosteal release, VRA was completed with two self-tapping screws, 1:1 mix of ABBM and particulate mineralized bone allograft, a cross-linked resorbable membrane, and a double line of suturing. Eight months postoperatively there was 5.3 mm of bone regeneration on the vertical dimension and 3.9 mm on the horizontal dimension. An implant was placed with primary stability of 45 Ncm. CONCLUSION: Successful VRA can be achieved with proper flap management to achieve tension-free closure, a cross-linked collagen membrane, tenting screws, and a combination grafting technique. The VRA ranged from 4.0 to 7.9 mm.

Distinct Profiles of Specialized Pro-resolving Lipid Mediators and Corresponding Receptor Gene Expression in Periodontal Inflammation.

Polyunsaturated fatty acid-derived specialized pro-resolving lipid mediators (SPMs) play an important role in modulating inflammation. The aim of the study was to compare profiles of SPMs, SPM related lipid mediators and SPM receptor gene expression in gingiva of subjects with periodontitis to healthy controls. A total of 28 subjects were included; 13 periodontally healthy and 15 periodontitis before or after non-surgical periodontal therapy. Gingival tissues were collected from two representative posterior teeth prior to and 8 weeks after scaling and root planning; only once in the healthy group. Lipid mediator-SPM metabololipidomics was performed to identify metabolites in gingiva. qRT-PCR was performed to assess relative gene expression (2-ΔΔCT) of known SPM receptors. Intergroup comparisons were made using Wilcoxon tests. Thirty-six omega-6 or omega-3 fatty acid-derived lipid mediators and seven receptor genes were identified in gingiva. Profiles of lipid mediators and receptor gene expression were significantly different between the three groups. Levels of six lipid mediators, 5-HETE, 15-HETE, 15(S)-HEPE, 4-HDHA, 7-HDHA, and 17-HDHA in periodontitis before treatment were significantly higher than in periodontitis after treatment. The expression of BLT1 in the healthy group was significantly higher than periodontitis subjects before and after treatment. The expression of GPR18 in periodontitis before treatment was significantly higher than in periodontitis after treatment while the expression of GPR32 in periodontitis before treatment was significantly lower than in periodontitis after treatment. Elevated levels of SPM biosynthetic pathway markers in periodontitis subjects before treatment indicated inflammation induced pro-resolution activity in gingiva, but receptors for these molecules were deficient in periodontitis pre-treatment suggesting that failure of resolution of inflammation contributes to excess, chronic inflammation in periodontitis.

Antimicrobial Efficacy Assessment of Human Derived Composite Amnion-Chorion Membrane.

Human derived composite amnion-chorion membrane (ACM) has been used to facilitate wound healing due to reported anti-inflammatory properties and promotion of cell proliferation. This study aimed to assess the antimicrobial properties of the ACM using novel methods to visualize the antimicrobial efficacy of membranes in situ at different time points. Porcine Pericardium Collagen Membranes (PPCM) served as membrane controls. Circular pieces of the membranes were used in three different assays: insert, agar contact and glass-bottom well assays. Streptococcus gordonii were spotted onto the membranes and the plates were subsequently centrifuged to ensure direct bacterial contact with the membranes in the insert and agar contact assays, thus better mimicking bacterial adherence in the oral cavity. After incubation at 37 °C for 8, 24, and 48 hours, the membranes were dyed with the Live/Dead BacLight Bacterial Viability fluorescence stain and analyzed via confocal microscopy. The results demonstrated that the ACM completely inhibited bacterial growth at all time points, whereas the PPCM did not demonstrate any antimicrobial properties. Within the limits of this study, the ACM showed extremely high antimicrobial efficacy against oral streptococci. In addition, our methods may be useful in assessing antimicrobial properties for biomaterials with minimum diffusion ability, when traditional assessment methods are not applicable.

Frequency of Tongue Cleaning Impacts the Human Tongue Microbiome Composition and Enterosalivary Circulation of Nitrate.

The oral microbiome has the potential to provide an important symbiotic function in human blood pressure physiology by contributing to the generation of nitric oxide (NO), an essential cardiovascular signaling molecule. NO is produced by the human body via conversion of arginine to NO by endogenous nitric oxide synthase (eNOS) but eNOS activity varies by subject. Oral microbial communities are proposed to supplement host NO production by reducing dietary nitrate to nitrite via bacterial nitrate reductases. Unreduced dietary nitrate is delivered to the oral cavity in saliva, a physiological process termed the enterosalivary circulation of nitrate. Previous studies demonstrated that disruption of enterosalivary circulation via use of oral antiseptics resulted in increases in systolic blood pressure. These previous studies did not include detailed information on the oral health of enrolled subjects. Using 16S rRNA gene sequencing and analysis, we determined whether introduction of chlorhexidine antiseptic mouthwash for 1 week was associated with changes in tongue bacterial communities and resting systolic blood pressure in healthy normotensive individuals with documented oral hygiene behaviors and free of oral disease. Tongue cleaning frequency was a predictor of chlorhexidine-induced changes in systolic blood pressure and tongue microbiome composition. Twice-daily chlorhexidine usage was associated with a significant increase in systolic blood pressure after 1 week of use and recovery from use resulted in an enrichment in nitrate-reducing bacteria on the tongue. Individuals with relatively high levels of bacterial nitrite reductases had lower resting systolic blood pressure. These results further support the concept of a symbiotic oral microbiome contributing to human health via the enterosalivary nitrate-nitrite-NO pathway. These data suggest that management of the tongue microbiome by regular cleaning together with adequate dietary intake of nitrate provide an opportunity for the improvement of resting systolic blood pressure.

Regeneration of degree ii furcation defects with a 4% doxycycline hyclate bioabsorbable barrier.

BACKGROUND: Bacterial contamination of a healing regenerative site has been shown to affect the response to therapy adversely. Doxycycline possesses antibacterial properties as well as other biologic actions that may result in an increased production and maintenance of collagen and bone. The purpose of this study was to assess if the sustained release of 4% doxycycline through a bioabsorbable barrier would enhance the regenerative outcomes of healing furcation sites. METHODS: Individuals with a single degree II furcation defect in a mandibular molar participated. They were assigned randomly to one of three treatment groups: poly(DL-lactide) polylactic acid (PLA) barrier containing 4% doxycycline hyclate + demineralized freeze-dried bone allograft (DFDBA) (BG+PDox); poly(DL-lactide) PLA barrier without doxycycline + DFDBA (BG+P); or DFDBA alone (BG). Clinical parameters included vertical probing depth (VPD), vertical clinical attachment level (VCAL), gingival recession, and horizontal probing depth (HPD). Intrasurgical measurements to calculate vertical and horizontal furcation fill were obtained at the time of surgery (baseline) and during a reentry procedure 9 months later. Statistical tests were used to assess changes in the clinical and surgical parameters before and after treatment among groups and within each group. RESULTS: Mean changes at 9 months for all groups yielded VPD reductions and VCAL gains. However, no significant difference was noted for the group that was treated with 4% doxycycline barrier compared to the other two groups. Vertical bone fill was 0.89, 1.44, and 1.18 mm for the BG+PDox, BG+P, and BG groups, respectively. Furcation horizontal bone was 2.33, 2.11, and 1.18 mm for the BG+PDox, BG+P, and BG groups, respectively. CONCLUSIONS: Addition of doxycycline to the guided tissue regeneration barrier did not enhance treatment outcomes compared to the non-antibiotic-loaded barrier or bone graft alone. All treatment modalities provided similar improvement in clinical and intrasurgical parameters.

Survival of Dental Implants Replacing Previously Failed Implants: A Retrospective Study in a University Setting.

PURPOSE: The rate of dental implant failures ranges from 3% to 8%, with that number increasing as the number of implants placed increases. When an implant fails, the survival rate drops significantly when a second or third attempt is performed. The aim of this study was to evaluate the survival rate of an implant placed in a previously failed implant site and to explore the risk factors that might affect the outcome of the second procedure. MATERIALS AND METHODS: A retrospective chart review was conducted for patients receiving dental implants at the University of Texas, School of Dentistry from 1985 to 2017. Exclusion criteria included patients with genetic diseases, radiation and chemotherapy, or an age less than 18 years. Data on age, sex, race, tobacco use, diabetes, cardiovascular, osteoporosis, implant brand, anatomical location of the implant, implant length and width, respective information on the replacement implant, and professional maintenance were collected for analysis. RESULTS: A total of 1,234 patients with 2,742 implants were included. A chart review found that of the 247 failed implants, replacement of implants was performed in 85 patients with 99 implants. More than half of the initial implants failed within the first year of placement. Based on the 12-month performance of each brand, the initially failed implants were categorized as high, medium, or low survival rates. Based on this categorization, the replacement implants that belonged to the medium survival rate category showed higher survival rates than the high survival group of the initially failed implants. CONCLUSION: The cumulative survival rates of the replacement implants were 91% at 1 year, 88% at 5 years, and 83% at 10 years. Implant failures were more common prior to functional loading.