Expansion of the sagittal suture induces proliferation of skeletal stem cells and sustains endogenous calvarial bone regeneration.

In newborn humans, and up to approximately 2 y of age, calvarial bone defects can naturally regenerate. This remarkable regeneration potential is also found in newborn mice and is absent in adult mice. Since previous studies showed that the mouse calvarial sutures are reservoirs of calvarial skeletal stem cells (cSSCs), which are the cells responsible for calvarial bone regeneration, here we hypothesized that the regenerative potential of the newborn mouse calvaria is due to a significant amount of cSSCs present in the newborn expanding sutures. Thus, we tested whether such regenerative potential can be reverse engineered in adult mice by artificially inducing an increase of the cSSCs resident within the adult calvarial sutures. First, we analyzed the cellular composition of the calvarial sutures in newborn and in older mice, up to 14-mo-old mice, showing that the sutures of the younger mice are enriched in cSSCs. Then, we demonstrated that a controlled mechanical expansion of the functionally closed sagittal sutures of adult mice induces a significant increase of the cSSCs. Finally, we showed that if a calvarial critical size bone defect is created simultaneously to the mechanical expansion of the sagittal suture, it fully regenerates without the need for additional therapeutic aids. Using a genetic blockade system, we further demonstrate that this endogenous regeneration is mediated by the canonical Wnt signaling. This study shows that controlled mechanical forces can harness the cSSCs and induce calvarial bone regeneration. Similar harnessing strategies may be used to develop novel and more effective bone regeneration autotherapies.

Clinical efficacy of the graft free slit-window sinus floor elevation procedure: A 2-year randomized controlled clinical trial.

OBJECTIVE: Slit-window technique is a lateral approach sinus floor elevation (SFE) procedure that utilizes a rigid resorbable membrane in conjunction with stabilizing bony slits to tent the Schneiderian membrane without addition of grafting materials. The aim of this randomized clinical trial was to compare clinical and radiographic outcomes of the Slit-window SFE with those of SFE with bone grafting. MATERIAL AND METHODS: Thirty-three patients with 38 edentulous sites were included. Edentulous sites were randomly allocated to the Slit-window SFE or SFE with bone grafting. Simultaneous with SFE, each site received two dental implants. Implant stability quotient (ISQ) values were recorded at baseline and monthly visits for 8 months. The bone coverage and bone height gain at implant sites were recorded on cone beam computed tomography (CBCT) scans 6 and 24 months postoperatively. RESULTS: There were no significant differences in the mean ISQ values between the groups at any time point (p > 0.05). All implants in both groups were found to have complete bone coverage. Significant increases in the bone height were found 6 and 24 months postoperatively in both groups (p < 0.001). CONCLUSIONS: Within limitations of the present study, it can be concluded that the Slit-window SFE technique without the need for bone grafting resulted in sufficient bone height gain around implants placed simultaneous with the SFE procedures. The bone height around these implants was stable during the 2-year follow-up period. The treatment outcomes for these implants were comparable to those placed simultaneous with lateral approach SFE in conjunction with bone grafting.

Clinical Outcomes of Comparing Soft Tissue Alternatives to Free Gingival Graft: A Systematic Review and Meta-Analysis.

OBJECTIVES: This systematic review and meta-analysis aimed to compare clinical outcomes and width of keratinized tissue (KT) around teeth, following the soft tissue alter- natives and free gingival graft (FGG) procedures. The specific graft materials that were explored were extracellular matrix membrane, bilayer collagen membrane, living cellular construct, and acellular dermal matrix. METHODS: Four different databases were queried to identify human controlled clinical trials and randomized controlled clinical trials that fulfilled the eligibility criteria. Relevant studies were identified by 3 independent reviewers, compiling the results of the electronic and handsearches. Studies identified through electronic and handsearches were reviewed by title, abstract, and full text using Covidence Software. Primary outcome in the present study was change in the width of KT. Results of the included studies were pooled to estimate the effect size, expressed as weighted mean differences and 95% confidence interval. A random-effects model was used to perform the meta-analyses. RESULTS: Six hundred thirty-eight articles were screened by title, 55 articles were screened by abstracts, and 34 full-text articles were reviewed. Data on quantitative changes in width of KT were provided in 7 studies. Quantitative analyses revealed a significant difference in changes in width of KT between patients treated with soft tissue alternatives and patients treated with FGGs (P < .001). The weighted mean difference of changes in the width of KT was 21.39 (95% confidence interval: 21.82 to 20.96; heterogeneity I 5 70.89%), indicating patients who were treated with soft tissue alternatives gained 1.39 mm less KT width compared with the patients who received free gingival graft. CONCLUSIONS: Based on the clinical outcomes, the results of this systematic review and meta-analysis showed that soft tissue alternatives result in an increased width of KT. Patients in the soft tissue alternatives group obtained 1.39 mm less KT compared with those in the FGGs group.

Potential for Stem Cell-Based Periodontal Therapy.

Periodontal diseases are highly prevalent and are linked to several systemic diseases. The goal of periodontal treatment is to halt the progression of the disease and regenerate the damaged tissue. However, achieving complete and functional periodontal regeneration is challenging because the periodontium is a complex apparatus composed of different tissues, including bone, cementum, and periodontal ligament. Stem cells may represent an effective therapeutic tool for periodontal regeneration due to their plasticity and their ability to regenerate different tissues. This review presents and critically analyzes the available information on stem cell-based therapy for the regeneration of periodontal tissues and suggests new avenues for the development of more effective therapeutic protocols.

Oral Impacts on Daily Performance in 20- to 50-yearolds Demanding Dental Care in Tehran, Iran: Association with Clinical Findings and Self-reported Health.

PURPOSE: To determine the prevalence and intensity of oral impacts on daily performance in 20- to 50-year-olds attending the dental clinic at Tehran Dental School and to investigate the association between the Oral Impacts on Daily Performance (OIDP) score, self-reported oral and general health and clinical findings of oral health. MATERIALS AND METHODS: The study population comprised 20- to 50-year-olds attending the dental clinic before receiving any treatments. Data were collected using questionnaire-led interviews and clinical examinations. The questionnaire consisted of a validated questionnaire of the Persian version of the OIDP index, sociodemographic characteristics and self-reported general and oral health of subjects. The number of teeth, prosthetic status and the decayed, missing and filled tooth score (DMFT) were recorded according to WHO criteria. Statistical analyses were performed by Wilcoxon test and linear regression modeling. RESULTS: A total of 499 individuals participated in the study. Among the subjects, 82.6% had experienced one or more oral impacts on their daily activities, and 49.5% of impacts were reported to be of severe or very severe intensity. Eating was the performance most frequently affected (50.1%) followed by smiling (16.2%) and sleeping (11.8%). The OIDP score was higher in the participants with a lower wealth index (P = 0.015) and in those with more decayed teeth (P = 0.013). The association between self-reported oral health and OIDP score was of borderline significance (P = 0.05). CONCLUSION: Oral health status has an enormous impact on the daily performance of Iranian adults attending the dental care center. More emphasis on oral health care in disadvantaged populations, particularly in countries with a developing oral health system, is required.

Clinical Outcomes of Metal-Ceramic versus Metal-Acrylic Resin Implant-Supported Fixed Complete Dental Prostheses: A Systematic Review and Meta-analysis.

PURPOSE: To compare the clinical outcomes of metal-ceramic vs metal-acrylic resin implant-supported fixed complete denture prostheses (IFCDPs). MATERIALS AND METHODS: An electronic literature database search was conducted in the CINAHL, EMBASE, PubMed, and Web of Science databases. Additionally, a manual search of the literature was performed. Studies conducted in edentulous human subjects comparing clinical outcomes of metal-acrylic resin IFCDPs to those of metal-ceramic IFCDPs were included if quantitative outcomes for the following variables were reported: implant failure, prosthetic failure, incidence of peri-implantitis, incidence of peri-implant mucositis, incidence of peri-implant mucosal recession, prosthetic complications, and any patient-centered outcomes. Data from included studies were pooled to estimate effect size. RESULTS: Five studies met the inclusion criteria. A quantitative analysis was possible for risk of implant failure, prosthesis failure, and incidence of peri-implantitis. Meta-analysis showed no statistically significant differences in the risk of implant or prosthesis failure between the two groups. However, meta-analysis showed a significantly greater risk of developing peri-implantitis at the implant level in the metal-acrylic group when compared to the metal-ceramic group (risk difference = 0.069; 95% CI = 0.028 to 0.06; P = .001; fixed-effects model). Furthermore, descriptive analysis of the literature indicated a higher incidence of other biologic complications such as peri-implant mucositis and peri-implant mucosal recession, as well as prosthetic complications such as abrasion and veneer fracture, in metal-acrylic resin IFCDPs compared to metal-ceramic IFCDPs. CONCLUSION: The available evidence suggests that a higher incidence of biologic and prosthetic complications, including a higher risk of peri-implantitis, are present with metal-acrylic resin IFCDPs compared to metal-ceramic IFCDPs.

Does implant staging choice affect crestal bone loss?

PURPOSE: The purpose of the present study was to compare the crestal bone loss around implants placed according to either a 1-stage or 2-stage implant installation procedure using a digital subtraction radiography technique. MATERIALS AND METHODS: In the present randomized clinical trial, screw-shaped tapered implants were inserted in the posterior mandible of patients needing fixed partial dentures. In each edentulous area, according to the randomization table, 1 implant was inserted using a 1-stage procedure (group 1) and 1 was placed using a 2-stage approach (group 2). The implants were temporized with the relined denture after 2 weeks. All implants were functionally loaded with fixed partial dentures after 3 months. Crestal bone loss (primary outcome variable) was measured using a digital subtraction radiography technique. Standardized radiovisiographs were taken after implant insertion, after fixed partial denture installation (3 months after surgery), and after 6 and 12 months of functional loading. The data were analyzed using the Wilcoxon signed ranks test (α = 0.05). RESULTS: Eleven patients (mean age 46.9 years, 3 women and 8 men) were included in the study. A total of 34 implants were inserted, 17 using a 1-stage protocol and 17 using a 2-stage protocol. Three months after implant placement, the 2-stage implants showed significantly more crestal bone loss (0.65 ± 0.71 mm) than the 1-stage implants (0.41 ± 0.53 mm; P = .02). However, after 6 and 12 months of functional loading, both groups showed comparable changes in bone level (P > .05). CONCLUSIONS: No differences were found between 1-stage and 2-stage implant placement in crestal bone loss after 1 year of functional loading.

Oral health status of individuals with obsessive-compulsive disorder considering oral hygiene habits.

AIMS: This study aimed to evaluate the oral health status of individuals with obsessive-compulsive disorder (OCD). METHODS: Ninety-two participants, aged 18 years and older from which 46 had OCD symptoms, were included in this comparative cross-sectional study. Data on age, sex, smoking habit, educational level, and potential mediators including brushing frequency (BF) and brushing duration (BD) were collected. Clinical examinations determined outcome measures including decayed-missing-filled teeth (DMFT), presence of root caries (PoRC), gingival recession (GR), plaque index (PI), and papillary bleeding index (PBI). Pathway analysis was used for data analysis. RESULTS: Individuals with OCD had significantly lower DMFT (p < .01), higher BF (p = .01), and lower PI (p = .01); however, there were no significant differences regarding BD, GR, PBI, and PoRC (p > .05). While BD did not have a mediating role, BF mediated the effect of OCD on DMFT (B = -0.31, CI = -0.60 to -0.06) and PI (B = -0.15, CI = -0.36 to -0.03). Males had less PI (B = -1.03, CI = -1.81 to -0.24) and PBI (B = -1.14, CI = -2.09 to 0.20) than females. Except for OCD and sex, other predictors were not significant. CONCLUSIONS: Individuals with OCD had lower caries experience and similar gingival health compared to controls. Part of the impact of OCD was mediated through brushing habits.

Efficacy of Nd:YAG laser-assisted periodontal therapy for the management of periodontitis: A double-blind split-mouth randomized controlled clinical trial.

BACKGROUND: This study aimed to explore the efficacy of Nd:YAG laser-assisted periodontal therapy for management of patients with stage II-IV periodontitis. METHODS: Patients who presented with residual periodontal pockets were enrolled. After non-surgical periodontal therapy (NSPT), test sites received Nd:YAG laser (first entrance to pocket: 3 W, 100 µs, 20 Hz; second entrance: 4 W, 600 µs, 20 Hz) and control sites received placebo (laser off). Periodontal probing depth (PPD), clinical attachment level (CAL), gingival recession (GR), bleeding on probing (BOP), and plaque index (PI) were recorded at baseline and 1, 2, 3, 4 and 6-month visits. RESULTS: Twenty patients completed the 6-month period. Significant reductions in PPD, CAL, BOP, and PI values and a significant increase in GR at all follow-up visits compared to the baseline (all P < 0.001) were revealed in both groups. Test sites showed significantly greater improvement in PPD (P = 0.0002) and greater increase in GR (P < 0.0001) compared to the control sites at 6-month visit. There was no difference between two groups regarding CAL gain through the study period (P = 0.23). CONCLUSION: NSPT+Nd:YAG laser with the current protocol results in greater PPD reduction compared to NSPT alone. However, this reduction is likely because of greater GR rather than attachment gain. Therefore, the adjunction of Nd:YAG laser (with the current setting) to the NSPT for the treatment of residual periodontal pockets did not ameliorate the clinical outcomes (ClinicalTrials.gov ID: NCT03365167).

Effect of prophylactic application of doxycycline at the implant-abutment interface on the outcomes of implant therapy: a split-mouth randomized clinical trial.

OBJECTIVES: Doxycycline hyclate is a controlled-release doxycycline polymer which can locally be applied. This study aimed to assess the effects of the prophylactic application of doxycycline hyclate at the implant-abutment interface on the short-term outcomes of implant therapy. METHOD AND MATERIALS: The present split-mouth randomized clinical trial included 20 subjects who received two mandibular implants bilaterally (40 implants in total). In the test side (n = 20), doxycycline hyclate was injected at the implant-abutment interface at the time of delivery of final prosthesis. No intervention was performed for the control side (n = 20). The marginal bone level on mesial and distal implant surfaces, bleeding on probing, pocket probing depth, and incidence of peri-implant mucositis were recorded at baseline and after 3, 6, and 12 months. RESULTS: Significant differences were found between the test and control sites, all favoring the test group, for marginal bone level changes at mesial and distal implant surfaces as well as for changes in pocket probing depth after 6 and 12 months. Furthermore, the numbers of implants with bleeding on probing and risk of developing peri-implant mucositis were significantly greater in the control group compared to the test group at 3-months, 6-months, and 12-months following baseline. CONCLUSIONS: Within the limitations of this study, it can be concluded that prophylactic application of doxycycline hyclate at the implant-abutment interface results in reduced crestal bone resorption and pocket probing depth levels. In addition, it reduces the risk of developing peri-implant mucositis.

Efficacy of photobiomodulation therapy on neurosensory recovery in patients with inferior alveolar nerve injury following oral surgical procedures: a systematic review.

OBJECTIVE: The present systematic review aimed to assess the efficacy of photobiomodulation (PBM) therapy on neurosensory recovery of patients with inferior alveolar nerve injury following third molar surgery or dental implant placement. METHOD AND MATERIALS: An electronic search was carried out in Scopus, Embase, Medline, PubMed, Web of Science, Cochrane Library, and Google Scholar databases. Among 1,122 identified papers, seven articles (three RCTs, one observational study, and three case series) met the inclusion criteria.
Results: Time lapse from nerve injury to the onset of PBM therapy varied widely from 2 days to 4 years. The number of patients in each study ranged between 4 and 74. In the majority of the studies, PBM was done using a diode laser at wavelengths ?in the range of 808 to 830 nm with power of 5 to 500 mW and radiation dose of 3 to 244 J/cm2. Two out of three RCTs found significant neurosensory recovery in the patients who received PBM therapy compared to the controls. The observational study and all case series reported significant improvement in the neurosensory status following PBM therapy. The degree of neurosensory recovery was found to be greater in younger patients and those who received the treatment within 6 months following the injury.
Conclusions: Due to the limited number of well-designed RCTs and small number of patients in each study, it is not possible to make a clear conclusion about the efficacy of PBM therapy on neurosensory recovery in patients with inferior alveolar nerve injury following third molar or implant procedures. Considering the possibility of spontaneous inferior alveolar nerve recovery during this period, the conclusion based on the studies with no control group should be interpreted with caution. (Quintessence Int 2021;52:140-153; doi: 10.3290/j.qi.a45430).

Effect of Application of a Bio-Adhesive on the Removal Torque Value and Rotational Misfit at the Implant-Abutment Junction: An In Vitro Study.

The aim of this study was to assess the effect of application of a recently developed bio-adhesive (Impladhesive) to abutment screw threads on the removal torque value and rotational misfit at the implant-abutment junction. This in vitro study evaluated 20 implant fixtures and 20 straight abutments. Specimens were randomly divided into two groups (n = 10) with/without adhesive application. In the adhesive group, the abutment was dipped in Impladhesive before torquing. In the control group, the abutment was torqued conventionally without adhesive application. The removal torque value was recorded after completion of the cyclic loading of 500,000 cycles with 2 Hz frequency and 75 N load. Rotational misfit was recorded using a video measuring machine. After applying the torque, the change in the bisector angle on the abutment hex was recorded for each implant. The biocompatibility of Impladhesive was evaluated using a MTT cell vitality assay. Normal distribution of data was assessed using the Kolmogorov-Smirnov test. Data were analyzed using a t-test and Pearson's correlation coefficient The application of Impladhesive at the implant-abutment interface resulted in significantly greater mean removal torque value compared to the control group (p = 0.008). In addition, the mean rotational misfit at the implant-abutment interface was significantly lower in the use of Impladhesive compared to the control group (p = 0.001). In addition, the cell vitality was found to be greater than 80% at all evaluated time points. It can be concluded that the application of Impladhesive on the abutment screw significantly decreased rotational misfit and increased the removal torque value. Future studies are needed to evaluate the efficacy of this bio-adhesive an in vivo setting.

Repeated delivery of chlorhexidine chips for the treatment of peri-implantitis: A multicenter, randomized, comparative clinical trial.

BACKGROUND: Peri-implantitis is a challenging condition to manage and is frequently treated using non-surgical debridement. The local delivery of antimicrobial agents has demonstrated benefit in mild to moderate cases of peri-implantitis. This study compared the safety and efficacy of chlorhexidine gluconate 2.5 mg chip (CHX chips) as an adjunctive treatment to subgingival debridement in patients afflicted with peri-implantitis. METHODS: A multicenter, randomized, single-blind, two-arm, parallel Phase-3 study was conducted. Peri-implantitis patients with implant pocket depths (IPD) of 5-8 mm underwent subgingival implant surface debridement followed by repeated bi-weekly supragingival plaque removal and chlorhexidine chips application (ChxC group) for 12 weeks, or similar therapy but without application of ChxC (control group). All patients were followed for 24 weeks. Plaque and gingival indices were measured at every visit whereas IPD, recession, and bleeding on probing were assessed at 8, 12, 16, 24 week. RESULTS: A total of 290 patients were included: 146 in the ChxC group and 144 in the control. At 24 weeks, a significant reduction in IPD (P = 0.01) was measured in the ChxC group (1.76 ± 1.13 mm) compared with the control group (1.54 ± 1.13 mm). IPD reduction of ≥2 mm was found in 59% and 47.2% of the implants in the ChxC and control groups, respectively (P = 0.03). Changes in gingival recession (0.29 ± 0.68 mm versus 0.15 ± 0.55 mm, P = 0.015) and relative attachment gain (1.47 ± 1.32 mm and 1.39 ± 1.27 mm, P = 0.0017) were significantly larger in the ChxC group. Patients in the ChxC group that were < 65 years exhibited significantly better responses (P < 0.02); likewise, non-smokers had similarly better response (P < 0.02). Both protocols were well tolerated, and no severe treatment-related adverse events were recorded throughout the study. CONCLUSIONS: Patients with peri-implantitis that were treated with an intensive treatment protocol of bi-weekly supragingival plaque removal and local application of chlorhexidine chips had greater mean IPD reduction and greater percentile of sites with IPD reduction of ≥2 mm as compared with bi-weekly supra-gingival plaque removal.

Effect of gingival phenotype on the maintenance of periodontal health: An American Academy of Periodontology best evidence review.

BACKGROUND: Gingival thickness, keratinized tissue width, and bone morphotype are three important parameters used to categorize periodontal phenotypes. These elements all play an important role in the maintenance of periodontal health. The aim of this review is to explore the importance of converting thin phenotype into a thick phenotype for periodontal health maintenance. METHODS: Three clinically relevant focused questions were defined to understand the role of gingival phenotype around teeth. 1) What are the factors affecting gingival phenotype (e.g., age, sex, dental arch, race, crown forms, etc.)? 2) Is there a difference between thin versus thick gingival phenotype in terms of gingival health? 3) Does the conversion of gingivae from a thin to thick gingival phenotype in sites without mucogingival defects help with periodontal health maintenance? RESULTS: Extensive electronic and manual literature search identified a total of 1,129 citations. After title, abstract, and full-text screenings, 30 articles were included in the present review. Twenty-five studies met the inclusion criteria and provided data for focused question 1. It was found that periodontal phenotype varies among different individuals and different areas of the mouth within the same individual. Asian individuals tend to have thinner gingival phenotype compared with white subjects. Eleven studies met the inclusion criteria for the focused question 2. Prevalence and severity of gingival recession was higher at the sites with thin gingiva compared with the sites with thicker gingiva. No studies provided data for focused question 3. CONCLUSIONS: Available evidence indicates that subjects with thin and narrow gingiva tend to have more gingival recession compared with those with thick and wide gingiva. Currently, there is no published evidence to support conversion of thin to thick gingival phenotype in sites without gingival recession or mucogingival deformity.

The Novel Periosteal Flap Stretch Technique: A Predictable Method to Achieve and maintain Primary Closure in Augmentative Procedures.

BACKGROUND: Correct soft tissue management and achieving tension-free primary closure are pre-requisites for the success of bone augmentation procedures. Several techniques have been developed to facilitate a passive soft tissue primary closure. However, the current techniques are highly invasive and require advanced surgical skills. Hence, the present case series report will describe a novel and simple flap management technique. METHODS: The Periosteal Flap Stretch technique was utilized in bone augmentation procedures for four patients who presented with horizontal and vertical alveolar ridge deficiencies in the anterior maxilla, anterior mandible, posterior mandible, and posterior maxilla. This technique is performed using a blunt surgical curette that engages the periosteum of the mucosa below the mucogingival line of the full-thickness flap and stretches the periosteum in a coronal and outward direction, which results in stretching of the flap without the need for vertical or periosteal releasing incisions. RESULTS: Healing was uneventful for four all cases. No membrane exposure, no soft tissue dehiscence, or any other complications were observed during the six-months healing period after the respective bone augmentation procedures of cases. CONCLUSIONS: The Periosteal Flap Stretch technique is a novel and simple technique that facilities achieving passive and predictable primary soft tissue closure.

Synthesis and characterization of osteoinductive visible light-activated adhesive composites with antimicrobial properties.

Orthopedic surgical procedures based on the use of conventional biological graft tissues are often associated with serious post-operative complications such as immune rejection, bacterial infection, and poor osseointegration. Bioresorbable bone graft substitutes have emerged as attractive alternatives to conventional strategies because they can mimic the composition and mechanical properties of the native bone. Among these, bioactive glasses (BGs) hold great potential to be used as biomaterials for bone tissue engineering owing to their biomimetic composition and high biocompatibility and osteoinductivity. Here, we report the development of a novel composite biomaterial for bone tissue engineering based on the incorporation of a modified strontium- and lithium-doped 58S BG (i.e., BG-5/5) into gelatin methacryloyl (GelMA) hydrogels. We characterized the physicochemical properties of the BG formulation via different analytical techniques. Composite hydrogels were then prepared by directly adding BG-5/5 to the GelMA hydrogel precursor, followed by photocrosslinking of the polymeric network via visible light. We characterized the physical, mechanical, and adhesive properties of GelMA/BG-5/5 composites, as well as their in vitro cytocompatibility and osteoinductivity. In addition, we evaluated the antimicrobial properties of these composites in vitro, using a strain of methicillin-resistant Staphylococcus Aureus. GelMA/BG-5/5 composites combined the functional characteristics of the inorganic BG component, with the biocompatibility, biodegradability, and biomimetic composition of the hydrogel network. This novel biomaterial could be used for developing osteoinductive scaffolds or implant surface coatings with intrinsic antimicrobial properties and higher therapeutic efficacy.

Outcome of early dental implant placement versus other dental implant placement protocols: A systematic review and meta-analysis.

BACKGROUND: The aim of this systematic review and meta-analysis was to compare the clinical efficacy of the early dental implant placement protocol with immediate and delayed dental implant placement protocols. METHODS: An electronic and manual search of literature was made to identify clinical studies comparing early implant placement with immediate or delayed placement. Data from the included studies were pooled and quantitative analyses were performed for the implant outcomes reported as the number of failed implants (primary outcome variable) and for changes in peri-implant marginal bone level, peri-implant probing depth, and peri-implant soft tissue level (secondary outcome variables). RESULTS: Twelve studies met the inclusion criteria. Significant difference in risk of implant failure was found neither between the early and immediate placement protocols (risk difference = -0.018; 95% confidence interval [CI] = -0.06, 0.025; P = 0.416) nor between early and delayed placement protocols (risk difference = -0.008; 95% CI = -0.044, 0.028; P = 0.670). Pooled data of changes in peri-implant marginal bone level demonstrated significantly less marginal bone loss for implants placed using the early placement protocol compared with those placed in fresh extraction sockets (P = 0.001; weighted mean difference = -0.14 mm; 95% CI = -0.22, -0.05). No significant differences were found between the protocols for the other variables. CONCLUSIONS: The available evidence supports the clinical efficacy of the early implant placement protocol. Present findings indicate that the early implant placement protocol results in implant outcomes similar to immediate and delayed placement protocols and a superior stability of peri-implant hard tissue compared with immediate implant placement.

An Antimicrobial Dental Light Curable Bioadhesive Hydrogel for Treatment of Peri-Implant Diseases.

Dental implants constitute the standard of care to replace the missing teeth, which has led to an increase in the number of patients affected by peri-implant diseases (PIDs). Here, we report the development of an antimicrobial bioadhesive, GelAMP, for the treatment of PIDs. The hydrogel is based on a visible light-activated naturally-derived polymer (gelatin) and an antimicrobial peptide (AMP). The optimized formulation of GelAMP could be rapidly crosslinked using commercial dental curing systems. When compared to commercial adhesives, the bioadhesives exhibited significantly higher adhesive strength to physiological tissues and titanium. Moreover, the bioadhesive showed high cytocompatibility and could efficiently promote cell proliferation and migration in vitro. GelAMP also showed remarkable antimicrobial activity against Porphyromonas gingivalis. Furthermore, it could support the growth of autologous bone after sealing calvarial bone defects in mice. Overall, GelAMP could be used as a platform for the development of more effective therapeutics against PIDs.

Faculty Development Initiatives in Academic Dentistry: A Systematic Review.

The aims of this systematic review were to collect a list of published articles on dental faculty development and to determine the types and location of programs evaluated and years of publication. A subset of selected articles were then assessed using Kirkpatrick assessment model four levels: learner reaction, participant learning, participant behavioral change, and changes in organizational practice. The search, conducted in 2016, comprised all potentially relevant articles in the following databases: PubMed, EMBASE via Ovid, and ERIC. The study screening was done by three reviewers in multiple stages: by title, abstract, and full text review. Following deduplication, 257 titles were obtained; of those, 102 articles were selected for abstract review. As a result of that review, 32 articles were excluded, leaving 70 for data extraction. The majority of the 70 articles were about programs in the U.S., and two-thirds were studies conducted at individual academic institutions. Most focused on faculty development initiatives (n=49), followed by retention (n=22), recruitment (n=16), and/or promotion/tenure (n=11). The year with the highest number of published articles was 1991 (n=10, 14%), followed by 2007 and 2011 (n=6, 8.6% each). Among the 12 articles evaluated with the Kirkpatrick model, most assessed Levels 1, 2, and 3, but very few addressed Level 4. Research in those 12 articles was conducted primarily at two dental schools: New York University College of Dentistry (n=5) and University of Florida College of Dentistry (n=4). This study generated a varied list of published articles on faculty development, but the results point to the need for research at more institutions and using additional methodologies.

Prx1 Expressing Cells Are Required for Periodontal Regeneration of the Mouse Incisor.

Previous studies have shown that post-natal skeletal stem cells expressing Paired-related homeobox 1 (PRX1 or PRRX1) are present in the periosteum of long bones where they contribute to post-natal bone development and regeneration. Our group also identified post-natal PRX1 expressing cells (pnPRX1+ cells) in mouse calvarial synarthroses (sutures) and showed that these cells are required for calvarial bone regeneration. Since calvarial synarthroses are similar to dentoalveolar gomphosis (periodontium) and since there is no information available on the presence or function of pnPRX1+ cells in the periodontium, the present study aimed at identifying and characterizing pnPRX1+ cells within the mouse periodontium and assess their contribution to periodontal development and regeneration. Here we demonstrated that pnPRX1+ cells are present within the periodontal ligament (PDL) of the mouse molars and of the continuously regenerating mouse incisor. By means of diphtheria toxin (DTA)-mediated conditional ablation of pnPRX1+ cells, we show that pnPRX1+ cells contribute to post-natal periodontal development of the molars and the incisor, as ablation of pnPRX1+ cells in 3-days old mice resulted in a significant enlargement of the PDL space after 18 days. The contribution of pnPRX1+ cells to periodontal regeneration was assessed by developing a novel non-critical size periodontal defect model. Outcomes showed that DTA-mediated post-natal ablation of pnPRX1+ cells results in lack of regeneration in periodontal non-critical size defects in the regeneration competent mouse incisors. Importantly, gene expression analysis of these cells shows a profile typical of quiescent cells, while gene expression analysis of human samples of periodontal stem cells (PDLSC) confirmed that Prx1 is highly expressed in human periodontium. In conclusion, pnPRX1+ cells are present within the continuously regenerating PDL of the mouse incisor, and at such location they contribute to post-natal periodontal development and regeneration. Since this study further reports the presence of PRX1 expressing cells within human periodontal ligament, we suggest that studying the mouse periodontal pnPRX1+ cells may provide significant information for the development of novel and more effective periodontal regenerative therapies in humans.