Hyaluronic Acid Is an Effective Dermal Filler for Lip Augmentation: A Meta-Analysis.

Introduction: The lips and the mouth play an indispensable role in vocalization, mastication and face aesthetics. Various noxious factors may alter and destruct the original structure, and appearance of the lips and the anatomical area surrounding the mouth. The application of hyaluronic acid (HA) may serve as a safe method for lip regeneration. Although a number of studies exist for HA effectiveness and safety, its beneficial effect is not well-established. Aim: The present meta-analysis and systematic review was performed to investigate the effectiveness of HA on lip augmentation. We also investigated the types and nature of adverse effects (AEs) of HA application. Methods: We reported our meta-analysis in accordance with the PRISMA Statement. PROSPERO protocol registration: CRD42018102899. We performed the systematic literature search in CENTRAL, Embase, and MEDLINE. Randomized controlled trials, cohort studies, case series and case reports were included. The untransformed proportion (random-effects, DerSimonian-Laird method) of responder rate to HA injection was calculated. For treatment related AEs descriptive statistics were used. Results: The systematic literature search yielded 32 eligible records for descriptive statistics and 10 records for quantitative synthesis. The results indicated that the overall estimate of responders (percentage of subjects with increased lip fullness by one point or higher) was 91% (ES = 0.91, 95% CI:0.85-0.96) 2 months after injection. The rate of responders was 74% (ES = 0.74, 95% CI:0.66-0.82) and 46% (ES = 0.46, 95% CI:0.28-0.65) after 6 and 12 months, respectively. We included 1,496 participants for estimating the event rates of AEs. The most frequent treatment-related AEs were tenderness (88.8%), injection site swelling (74.3%) and bruising (39.5%). Rare AEs included foreign body granulomas (0.6%), herpes labialis (0.6%) and angioedema (0.3%). Conclusion: Our meta-analysis revealed that lip augmentation with injectable HA is an efficient method for increasing lip fullness for at least up to 6 months after augmentation. Moreover, we found that most AEs of HA treatment were mild or moderate, but a small number of serious adverse effects were also found. In conclusion, further well-designed RCTs are still needed to make the presently available evidence stronger.

Long-term crestal bone changes in implants placed in augmented sinuses with minimal or moderate remaining alveolar bone: A 10-year retrospective case-series study.

OBJECTIVES: To evaluate long-term clinical and radiographic outcomes of dental implants placed after lateral window sinus augmentation utilizing the sagittal sandwich technique. MATERIALS AND METHODS: Patients treated with sinus augmentation were included in this retrospective case-series study. The surgical procedure was performed with particulate autogenous bone- and anorganic bovine bone-derived mineral (3:7 ratio). Implants were grouped based on baseline residual alveolar ridge height: group S (residual alveolar ridge height of 0.1-3.5 mm), group M (height of 3.5-7mm), and group C (native bone). Radiographs were taken at baseline (abutment installation) and annually throughout the 10-year follow-up. RESULTS: A total of 86 patients (92 sinus lifts) and 209 implants were included. Ten sinus membrane perforations were recorded (11% incidence), and graft infections occurred in 3 cases (3.2% incidence). During the 10-year follow-up, 3 implants (1.4%) failed. No significant differences in the mean implant marginal bone loss (MBL) between the three groups were found after 1-, 2-, and 5-year follow-up (p > .05). At 10 years, group C exhibited more MBL than group M with a mean difference of -0.53 mm (p = .01). After 10 years, MK III implants displayed significantly more bone loss in native bone than those in augmented bone with a mean difference of 0.48 mm (p = .02). Five patients and 7 implants developed peri-implantitis with no significant differences between the groups (p = .570). CONCLUSION: Implant placement after two-stage sinus grafting utilizing the sagittal sandwich technique is a relatively safe and predictable procedure with minimal complications and MBL after 10-year follow-up.

Comparative Evaluation of Two Hyaluronic Acid Gel Products for the Treatment of Interdental Papillary Defects.

OBJECTIVES: The aim was to investigate the efficacy of single injections of two different hyaluronic acid products, Flex Barrier and Revident, in reducing the size of black triangles to treat Nordland-Tarnow Class I and II recessions. MATERIALS AND METHODS: Forty adult patients were recruited with at least two upper and two lower interdental papilla defects in the front region between canine teeth. According to the Nordland-Tarnow classification of papillary defects, both Class I and Class II recessions were included in the investigation. Patients were randomly assigned to experimental groups to receive single injections of two different hyaluronic acid products, either Flex Barrier or Revident. The untreated sites served as controls. Photographs were taken before and immediately after the treatment, and again after one week and one month. To determine the size of the black triangles, Image J software was used. For statistical analysis, a mixed-design ANOVA was applied. RESULTS: Both Flex Barrier and Revident significantly decreased the size of the treated defects immediately after the treatment and also one week later (p<0.001). The beneficial effect of Revident lasted longer than Flex Barrier as it remained significant even after one month in Revident-treated patients, however, not in the Flex Barrier-treated group. Furthermore, Nordland-Tarnow Class I lesions generally showed a greater improvement than Class II lesions. CONCLUSION: In this proof-of-concept, randomized clinical trial we have demonstrated the clinical applicability of both Flex Barrier and Revident, although Revident gave longer-lasting improvements than Flex Barrier. Further trials are needed to optimize multiple-application protocols for treating gingival black triangles.

Sandblasting reduces dental implant failure rate but not marginal bone level loss: A systematic review and meta-analysis.

INTRODUCTION: Sandblasting is one of the oldest implant surface modifications to enhance osseointegration. Regarding its superiority over machined surface controversies still exist. Our objective was to compare implant failures (IF) and marginal bone level (MBL) changes between sandblasted and machined dental implants by a meta-analysis utilizing the available data. The PROSPERO registration number of the meta-analysis is CRD42018084190. METHODS: The systematic search was performed in Cochrane, Embase and Pubmed. Inclusion criteria included participants with neither systemic diseases, nor excessive alcohol consumption, nor heavy smoking. We calculated pooled Risk Ratio (RRs) with confidence intervals of 95% (CIs) for dichotomous outcomes (implant failure) and weighted mean difference (WMD) CIs of 95% for continuous outcomes (marginal bone level change). We applied the random effect model with DerSimonian-Laird estimation. I2 and chi2 tests were used to quantify statistical heterogeneity and gain probability-values, respectively. RESULTS: Literature search revealed 130 records without duplicates. Out of these, seven studies met the inclusion criteria and all were included in data synthesis, involving 362 sand-blasted and 360 machined implants. The results indicate that there is an 80% (RR = 0.2 95% CI:0.06-0.67; I2 = 0.0% p = 0.986) lower among sandblasted compared to machined implants after one year of use and 74% (RR = 0.26 95% CI:0.09-0.74; I2 = 0.0% p = 0.968) five years of use, respectively. In contrast, there is no significant difference in MBL (WMD:-0.10mm, 95% CI:-0.20, 0.01; p>0.05; I2 = 0.0%, p = 0.560 and WMD:-0.01mm, 95% CI:-0.12, 0.09; p>0.05; I2 = 26.2%, p = 0.258) between the two implant surfaces after one and five years of use. CONCLUSIONS: This meta-analysis reveals that sandblasting is superior over machined surface in implant failure but not in marginal bone level in healthy subjects. It also points out the need for further randomized clinical trials with large sample size for objective determination of the clinical benefits of certain implant surface modifications.

Development of a quantitative preclinical screening model for implant osseointegration in rat tail vertebra.

OBJECTIVES: Functional tooth replacement and bone regeneration are parts of the daily practice in modern dentistry, but well-reproducible and relatively inexpensive experimental models are still missing. We aimed to develop a new small animal model to monitor osseointegration utilizing the combination of multiple evaluation protocols. MATERIAL AND METHODS: After cutting the tail between the C4 and C5 vertebrae in Wistar rats, costume made, parallel walled, non-threaded implants were placed into the center of the tail parallel with its longitudinal axis using a surgical guide. Osseointegration of the titanium implants was followed between 4 and 16 weeks after surgery applying axial extraction force, and resonance frequency analysis as functional tests, and histomorphometry and micro-CT as structural evaluations. RESULTS: In functional tests, we observed that both methods are suitable for the detection of the time-dependent increase in osseointegration, but the sensitivity of the pull-out technique (an approximately five times increase with rather low standard error) was much higher than that of the resonance frequency analysis. In structural evaluations, changes in the detected bone implant contact values measured by histomorphometry (yielding 1.5 times increase, with low variations of data) were more reliable than micro-CT based evaluations to screen the developments of contact between bone and implant. CONCLUSION: Our results provide evidence that the caudal vertebrae osseointegration model is useful for the preclinical evaluation of implant integration into the bone. CLINICAL RELEVANCE: The combination of the biomechanical and structural tests offers a well-reproducible small animal system that can be suitable for studying the integration of various implant materials and surface treatments.

Sustained Release of Zoledronic Acid from Mesoporous TiO2-Layered Implant Enhances Implant Osseointegration in Osteoporotic Condition.

Implant surface modification that provides local sustained release of osteoinductive therapeutic agents enhances implant stability. We designed a mesoporous TiO2-layered titanium implant (MLT) by modified anodization technique that allowed local sustained release of zoledronic acid up to 21 days. Mesoporous layer has pore size 15 nm, depth ∼30 µm, volume 0.32 cm3/g, surface area 112.3 m2/g, surface roughness 20 nm and water contact angle 18.3°. Zoledronic acid-loaded MLT (MLT-Z) was biocompatible, showed anabolic effect on bone forming osteoblasts and catabolic effect on bone resorbing osteoclasts. MLT or MLT-Z implants were implanted in osteoporotic rat-tail vertebrae. Smooth implant in healthy rats were used as a positive control. Histomorphometric analysis showed that bone implant contact of smooth implant in osteoporotic rats was reduced by 4.1-fold compared to healthy rats and MLT-Z rescued the effect by 53%. Similar effect was observed in implant fixation, mechanical stability, BV/TV ratio, Tb.N, Tb.Th and OI% among the groups. Histological and µ-CT images strongly supported the above-mentioned findings. In conclusion, a novel surface-fabricated MLT-Z gives local sustained drug release, robustly enhances implant osseointegration and stability in osteoporotic condition, suggesting it as a promising implant model for patients with compromised bone quality.

Effectiveness of Two Different Lingual Flap Advancing Techniques for Vertical Bone Augmentation in the Posterior Mandible: A Comparative, Split-Mouth Cadaver Study.

Vertical ridge augmentation in the posterior mandible is a technique-sensitive procedure that requires adequate anatomical knowledge and precise surgical skills to minimize the risk of complications. One of the most important but also challenging aspects of the surgical technique is proper flap management to allow for passive flap closure and reduce the chances of postoperative complications affecting deep anatomical spaces. This article presents a detailed description of a novel lingual flap advancement technique and its validation via a split-mouth, comparative study using a cadaver model. A total of 12 fresh cadaver heads presenting bilateral posterior mandibular edentulism were selected. Sides were randomized to receive a classic lingual flap release technique (control) or the modified technique presented here, which involves the intentional preservation of the mylohyoid muscle attachment to the mandible. Vertical flap release was measured at three different zones using standard forces. The mean difference between the test and control group in zones I (retromolar pad area), II (middle area), and III (premolar area) was 8.273 ± 1.794 mm (standard error of the mean [SEM] = 0.5409 mm), 10.09 ± 2.948 mm (SEM = 0.8889 mm), and 10.273 ± 2.936 mm (SEM = 0.8851 mm), respectively, reaching very strong statistical significance (P < .0001) in all three zones.

Effect of stem cells of dental pulp origin on osseointegration of titanium implant in a novel rat vertebra model.

During that last decade a large number of experiments showed the successful application of stem cells in achieving large bone volume regeneration. On the contrary, our knowledge about the promotion of implant osseointegration by stem cell is sporadic. Recently, our research group has carried out an array of studies aiming the characterization of postnatal stem cells of dental origin. In addition, we have developed a novel quantitative model for implant osseointegration in rat tail vertebrae. In the present work we aimed to study how the implant osseointegration process is affected by mesenchymal stem cells of rat dental pulp origin (DPSC) when cells are undifferentiated or predifferentiated into osteogenic direction. Our results show that undifferentiated pulp cells inserted between the implant and the bone slow down the osseointegration process. On the other hand, pre-differentiated DPSCs do not have a similar adverse effect any more. Our data suggest that the success of mesenchymal stem cell application to promote implant osseointegration is highly dependent on the applied conditions, particularly on the parallel applicatioh of scaffolds and osteogenic components.

A New Rat Model for Translational Research in Bone Regeneration.

The European Union (EU) directive 2010/63/EU on the protection of animals used for scientific purpose focused on reducing the number of animals and refinement of breeding. Animal studies are necessary to protect human health. Lots of animal models exist to study bone regeneration, but a reliable, well reproducible, and relatively inexpensive model with the possibility for multiple testing in the same animal is still missing. Rats may serve as good models for this due to the small animal size and good cost/benefit ratio. The present study aimed to develop a novel rat caudal vertebrae critical size defect model for bone regeneration and implant osseointegration studies The study was performed using Wistar rats with weight from 380 to 450 g. An incision was made on the dorsal side of the tail. After skin and muscles retractions, the vertebrae were exposed. Critical size defects for bone tissue engineering or implant placements for titanium body experiments were possible in each of the first four caudal vertebrae. Micro-computed tomography (CT) and histology were used to detect bone growth. There was no bone formation in the defects after 1 or 2 months of healing. When a calcium phosphate biomaterial was used (Bio-Oss®; Geistlich Pharma AG, Wolhusen, Switzerland), a good stability of the material in the defect was noted and bone growth was visible after 1 or 2 months. Results based on implant placement showed good primary stability after 3 months of healing. MicroCT showed integrated implant position through the vertebra. These results suggest that the rat caudal vertebrae may serve as a good new model for studying bone regeneration and implant osseointegration with the possibility of multiple testing within the same experimental animal and the potential to decrease number of experimental animals.