Dental pulp stem cells for in vivo bone regeneration: A systematic review of literature

ObjectiveThis review of literature was aimed to assess in vivo experiments which have evaluated the efficacy of dental pulp stem cells (DPSCs) for bone regeneration.DesignAn electronic search of English-language papers was conducted on PubMed database. Studies that assessed the use of DPSCs in bone regeneration in vivo were included and experiments evaluating regeneration of hard tissues other than bone were excluded. The retrieved articles were thoroughly reviewed according to the source of stem cell, cell carrier, the in vivo experimental model, defect type, method of evaluating bone regeneration, and the obtained results. Further assessment of the results was conducted by classifying the studies based on the defect type.ResultsSeventeen papers formed the basis of this systematic review. Sixteen out of 17 experiments were performed on animal models with mouse and rat being the most frequently used animal models. Seven out of 17 animal studies, contained subcutaneous pockets on back of the animal for stem cell implantation. In only one study hard tissue formation was not observed. Other types of defects used in the retrieved studies, included cranial defects and mandibular bone defects, in all of which bone formation was reported.ConclusionWhen applied in actual bone defects, DPSCs were capable of regenerating bone. Nevertheless, a precise conclusion regarding the efficiency of DPSCs for bone regeneration is yet to be made, considering the limited number of the in vivo experiments and the heterogeneity within their methods.     

Dental implant placement through impacted teeth or residual roots as an alternative to invasive extraction surgeries: a systematic literature review

This work systematically reviews dental implant placement through impacted teeth or residual roots, as an alternative to invasive extraction surgeries, evaluated in terms of survival rates, marginal bone loss, surgical, and prosthetic complications. The authors conducted an electronic search of four databases up to September 2020; also a complementary handsearch was carried out. The quality of the included studies was assessed using a protocol for assessment of risk of bias in exposure studies. Ten studies fulfilled the inclusion criteria and were analysed. A total of 44 patients received 62 dental implants and were monitored for a minimum of 12-months follow-up. An overall mean implant survival rate was 90.32%, reporting 97.56 % for dental implants through impacted teeth and 76.19% through residual roots. No surgical or prosthetic complications were reported. Placing dental implants through impacted teeth may offer a valid therapeutic option for implant-supported restorations in patients for whom surgery and orthodontic traction are not possible, and/or patients who refuse to undergo more invasive extraction surgery. Moreover, additional caution is recommended when placing implants through retained root fragments, as this may involve long-term risk. Further research generating long-term data are needed to confirm these findings.     

The role of cortical perforations in bone regeneration: a systematic review

The aim of this review was to determine the effect of cortical perforations in bone regeneration considering the surgical technique. An electronic search in the PubMed (MEDLINE) and ScienceDirect databases and a hand search of the literature was conducted covering the period July 2008 to December 2018. Studies that specified the creation of perforations in the recipient area as a study variable associated with the regenerative technique were included. The quality of the randomized clinical trials included in this systematic review was also assessed. A total of 16 articles met both inclusion criteria and were eligible for analysis. Studies were grouped into three blocks according to the associated surgical technique. All studies were performed in an experimental model except for one. Qualitative assessment of the studies showed a moderate to high risk of bias of the overall studies. The evidence for creating perforations in guided bone regeneration and also in combination with autologous bone blocks in order to increase bone formation is limited according to the publications analysed. Although the number and size of perforations do not appear to interfere with the result, their effect in the upper maxilla and in the mandible should be evaluated separately due to the structural anatomical differences.     

Occlusion effects of bioactive glass and hydroxyapatite on dentinal tubules: a systematic review

Clinical Oral Investigations - Bioactive glass and hydroxyapatite are biocompatible materials used as an adjunct to various dental materials. The present study aimed to evaluate the occlusion...     

Nanocrystalline hydroxyapatite in periodontal bone regeneration: A systematic review

BackgroundPeriodontal diseases when persistent, results in periodontal pockets, attachment loss and progressive destruction of the alveolar bone. Grafting periodontal bone defects with bone substitute biomaterials has proven clinical success for accomplishing reconstruction of lost attachment apparatus, especially in deep intra-bony defects. Nanoparticles (NPs) have been considered indispensable in the future of health sciences and NP based alloplastic graft materials such as nanocrystalline hydroxyapatite (NCHA) hold great promise for regeneration of periodontal defects. Therefore the aim of this review is to evaluate the role of NCHA as an effective substitute for periodontal bone regeneration.Material & methodsPopular scientific databases such as PubMed (Medline), Cochrane database of clinical trials, Scopus (Elsevier), Web of science (Clarivate Analytics) and Google Scholar, were searched. The literature search was restricted to published reports in English, between January 2000 and December 2021. Database search returned 1227 results which were screened based on title, author names and publication dates.ResultsData from the 14 included studies were reviewed and tabulated. In the present review, all the studies reported using commercially available NCHA for periodontal bone regeneration.ConclusionNCHA is a suitable bone substitute material for periodontal bone regeneration, with outcomes comparable to that of conventionally used graft materials such as bovine xenograft and other synthetic alloplastic materials. While grafting with NCHA in intrabony periodontal defects, after any form of periodontal flap surgery or debridement, significantly improves bone regeneration by 6 months, addition of adjuncts like EMD and PRF further enhance the outcomes.     

Effect of platelet-rich plasma on bone regeneration in dentistry: a systematic review

Objective: To review systematically the reported effects of platelet‐rich plasma (PRP) on bone regeneration. Material and methods: Up to June 2006, MEDLINE and Cochrane databases were explored with different combinations of three search terms: ‘PRP’, ‘bone regeneration’, ‘dentistry’ and their synonyms. Inclusion criteria: human controlled clinical trials designed to treat maxillofacial bony defects with application of PRP (test) or without PRP (control), including at least five patients with a follow‐up period of more than 3 months and using clinical assessment, radiography, histology and/or histomorphometry for evaluation. Literature search, selection of eligible articles and data extraction were carried out independently by two readers. Results: The literature search revealed 108 references, of which 17 were selected for further analysis. Finally, nine articles fulfilling the inclusion criteria were selected for systematically review. Owing the substantial heterogeneity of the studies it was not possible to analyze the data statistically. An attempt was made to compare results from studies that used similar outcome measures by calculating and adding confidence intervals to the data presented in the original papers. Differences in treatment effects for periodontal defects in terms of clinical attachment level (CAL) were significant (ranging from 0.8 to 3.2 mm). The reported effects of PRP in sinus elevation (compared with their controls) were <10%. Conclusion: We found evidence for beneficial effects of PRP in the treatment of periodontal defects. Evidence for beneficial effects of PRP in sinus elevation appeared to be weak. No conclusions can be drawn about other applications of PRP in dentistry.     

Periodontal regeneration in aggressive periodontitis patients: A systematic review of the literature

The aim of the present study was to systematically review the existing literature on periodontal regenerative procedures in individuals affected by aggressive periodontitis (AgP). An electronic and manual search was performed using an ad hoc prepared search string. All types of study designs were considered acceptable for inclusion. Data about treated patients, baseline clinical parameters, type of surgery, and outcomes were extracted and recorded. A narrative evaluation of the results was performed. After the article‐selection process, a total of 22 full‐texts were included in the qualitative synthesis. Twelve papers were case reports; one was a retrospective study; six were non‐randomized, comparative studies; and three papers were published on two randomized, controlled trials (RCT). Various biomaterials and surgical techniques were described in the included papers. Based on the existing literature, even considering the relatively low level of evidence, periodontal regenerative surgery could be successfully performed in patients affected by AgP. There is a substantial need of high‐quality RCT to support this.     

The role of Vitamin D as an adjunct for bone regeneration: A systematic review of literature

Background and objectivesIn spite of bone’s healing capacity, critical-size bone defect regeneration and peri-implant osseointegration are challenging. Tissue engineering provides better outcomes, but requires expensive adjuncts like stem cells, growth factors and bone morphogenic proteins. Vitamin D (Vit.D) regulates calcium and phosphorus metabolism, and helps maintain bone health. Vit.D supplements in deficient patients, accentuates bone healing and regeneration. Therefore the aim of this systematic review was to evaluate the role of adjunctive Vit.D on bone defect regeneration.MethodsComprehensive database search of indexed literature, published between January 1990 and June 2022, was carried out. English language articles fulfilling inclusion criteria (clinical/in vivo studies evaluating bone regeneration including osseointegration and in vitro studies assessing osteogenic differentiation, with adjunct Vit.D) were identified and screened.ResultsDatabase search identified 384 titles. After sequential title, abstract and full-text screening, 23 studies (in vitro – 9/in vivo – 14) were selected for review. Vit.D as an adjunct with stem cells and osteoblasts resulted in enhanced osteogenic differentiation and upregulation of genes coding for bone matrix proteins and alkaline phosphatase. When used in vivo, Vit.D resulted in early and increased new bone formation and mineralization within osseous defects, and better bone implant contact and osseointegration, around implants. Adjunct Vit.D in animals with induced systemic illnesses resulted in bone defect regeneration and osseointegration comparable to healthy animals. While systemic and local administration of Vit.D resulted in enhanced bone defect healing, outcomes were superior with systemic route.ConclusionsBased on this review, adjunct Vit.D enhances bone defect regeneration and osseointegration. In vitro application of Vit.D to stem cells and osteoblasts enhances osteogenic differentiation. Vit.D is a potentially non-invasive and inexpensive adjunct for clinical bone regeneration and osseointegration. Long term clinical trials are recommended to establish protocols relating to type, dosage, frequency, duration and route of administration.     

A histologic study of bone response to bioactive glass particles used before implant placement: a clinical report

This clinical report describes the microscopic analysis of the postextraction bone response to bioactive glass particles used prior to titanium implant placement, after a healing period of 6 months. The clinical and radiographic follow-up were performed over a 3-year period after implantation.     

Effects of implant surface coatings and composition on bone integration: a systematic review

Objective: The aim of the present review was to evaluate the bone integration efficacy of recently developed and marketed oral implants as well as experimental surface alterations.
Materials and methods: A PubMed search was performed for animal studies, human reports and studies presenting bone-to-implant contact percentage or data regarding mechanical testing.
Results: For recently developed and marketed oral implants, 29 publications and for experimental surface alterations 51 publications fulfilled the inclusion criteria for this review.
Conclusions: As demonstrated in the available literature dealing with recently developed and marketed oral implants, surface-roughening procedures also affect the surface chemical composition of oral implants. There is sufficient proof that surface roughening induces a safe and predictable implant-to-bone response, but it is not clear whether this effect is due to the surface roughness or to the related change in the surface composition. The review of the experimental surface alterations revealed that thin calcium phosphate (CaP) coating technology can solve the problems associated with thick CaP coatings, while they still improve implant bone integration compared with non-coated titanium implants. Nevertheless, there is a lack of human studies in which the success rate of thin CaP-coated oral implants is compared with just roughened oral implants. No unequivocal evidence is available that suggests a positive effect on the implant bone integration of peptide sequences or growth factors coated on titanium oral implants. In contrast, the available literature suggests that bone morphogenetic protein-2 coatings might even impede the magnitude of implant-to-bone response.     

Bone regeneration with recombinant human bone morphogenetic protein 2: a systematic review

Aim

The aim of this work was to perform a systematic literature review on the clinical application of rhBMP-2 in bone reconstruction prior to placing implants.

Materials and Methods

A PUBMED search was made about the subject and nine clinical trials were selected according to strict inclusion criteria.

Results

Overall success rates of bone regeneration with rhBMP-2 was 81.4% and success of implants placed was 87.4%. Most frequent adverse events were pain, edema and erythema.

Conclusion

It was concluded that the treatment with rhBMP-2 foi satisfactory in most cases and the placement of dental implants in the bone regenerated with rhBMP-2 is feasible.

     

Success criteria in implant dentistry: a systematic review

The purpose of this study was to examine the most frequently used criteria to define treatment success in implant dentistry. An electronic MEDLINE/PubMED search was conducted to identify randomized controlled trials and prospective studies reporting on outcomes of implant dentistry. Only studies conducted with roughened surface implants and at least five-year follow-up were included. Data were analyzed for success at the implant level, peri-implant soft tissue, prosthetics, and patient satisfaction. Most frequently reported criteria for success at the implant level were mobility, pain, radiolucency, and peri-implant bone loss (> 1.5 mm), and for success at the peri-implant soft-tissue level, suppuration, and bleeding. The criteria for success at the prosthetic level were the occurrence of technical complications/prosthetic maintenance, adequate function, and esthetics during the five-year period. The criteria at patient satisfaction level were discomfort and paresthesia, satisfaction with appearance, and ability to chew/taste. Success in implant dentistry should ideally evaluate a long-term primary outcome of an implant-prosthetic complex as a whole.     

High-density polytetrafluoroethylene membranes in guided bone and tissue regeneration procedures: a literature review

Expanded polytetrafluoroethylene (e-PTFE) has been used successfully as a membrane barrier for regeneration procedures. However, when exposed to the oral cavity, its high porosity increases the risk of early infection, which can affect surgical outcomes. An alternative to e-PTFE is non-expanded and dense polytetrafluoroethylene (n-PFTE), which results in lower levels of early infection following surgical procedures. The aim of this literature review was to analyze and describe the available literature on n-PFTE, report the indications for use, advantages, disadvantages, surgical protocols, and complications. The medical databases Medline–PubMed and Cochrane Library were searched and supplemented with a hand search for reports published between 1980 and May 2012 on n-PTFE membranes. The search strategy was limited to animal, human, and in vitro studies in dental journals published in English. Twenty-four articles that analyzed the use of n-PTFE as a barrier membrane for guided tissue regeneration and guided bone regeneration around teeth and implants were identified: two in vitro studies, seven experimental studies, and 15 clinical studies. There is limited clinical and histological evidence for the use of n-PTFE membranes at present, with some indications in guided tissue regeneration and guided bone regeneration in immediate implants and fresh extraction sockets.     

The effect of smoking on periodontal bone regeneration: a systematic review and meta-analysis

Background: The effect of smoking on soft tissues after periodontal treatment has been extensively studied. However, little focus has been placed on the impact of smoking on bone regeneration after treatment. The aim of this review is to systematically assess the effect of smoking on bone regeneration after periodontal treatment. Methods: A protocol was established and studies were sourced from five electronic databases. Screening, data abstraction, and quality assessment was conducted by two review authors. Prospective and retrospective clinical studies assessing bone regeneration in smokers and non‐smokers after periodontal therapy were selected. In addition, arms of clinical trials comparing different interventions that reported results separately for smokers and non‐smokers were also included. Primary outcome measures were based on clinical and/or radiographic indicators of bone regeneration after periodontal therapy. The review and meta‐analysis followed many of the recommendations outlined in the preferred reporting items for systematic reviews and meta‐analyses statement. Results: Six of 10 studies included in this review concluded that smoking negatively influenced bone regeneration. A meta‐analysis of a subgroup of three studies demonstrated that smoking resulted in significantly less bone gain (P = 0.03) as measured by a change in the probing bone level after the treatment of intrabony defects with guided tissue regeneration. The meta‐analysis showed a standardized mean difference of ?2.05 (95% confidence interval: ?2.64 to ?1.47) using the random‐effects model. Conclusions: Smoking has a negative effect on bone regeneration after periodontal treatment. Patients should be advised that their smoking habit may result in poorer bone regeneration after periodontal treatment.     

数字化印模在口腔种植修复中的研究进展

数字化印模是指使用口内扫描仪在患者口内无需直接接触即获取组织图像,并合成三维牙列影像的印模技术。数字化印模于口腔种植修复中的应用近年来开始受到关注,但其印模精度尚不明确,尤其是多颗种植体的数字化印模精度。本文详细介绍数字化印模的原理、在种植修复不同类型牙列缺损或缺失情况下的精度以及影响精度的相关因素,以期为数字化印模在种植修复中的临床应用提供参考依据。     

Clinical outcomes of vertical bone augmentation to enable dental implant placement: a systematic review

Background: This review addressed the focused question of what is the predictability of vertical ridge augmentation techniques for patients, who were diagnosed with insufficient alveolar bone volume for the placement of dental implants.
Material and Methods: A systematic online review of three main databases was performed between 1966 and 1 November 2007. Four groups of vertical bone augmentation techniques have been identified and evaluated: (1) guided bone regeneration, (2) distraction osteogenesis, (3) onlay bone grafting, and (4) an array of different techniques. Data extraction was based on the following outcomes: (a) success and failure rate of the procedure (vertical bone gain/loss), (b) complication rate of the procedure, and (c) implant survival, success and failure rate.
Results: The initial search identified 189 papers from the electronic database. The review produced seven papers for GBR, 13 reporting distraction osteogenesis, five for onlay bone grafting and three describing different techniques.
Conclusions: For the concept of vertical ridge augmentation to enable dental implant placement, there are clinical and histological data supporting its potential use. Given the confined number of investigators using these techniques and the low number of patient treatments reported in the literature, the generalizability of this approach is limited at this time.     

上颌前牙单牙种植区采用钛膜引导成骨的效果观察

研究目的:上颌前牙单牙种植区,种植体颈部唇侧裂开性骨缺损或唇侧骨板厚度小于0.5mm时,采取不可吸收性钛膜引导成骨的效果及修复效果的前瞻性研究.材料及方法:2004年6月-2008年12月,在北京大学口腔医学院种植中心,18例上颌前牙单牙缺失患者(男12例,女6例,年龄19-56岁,平均38.6岁),要求采取种植修复,身体健康,不吸烟.种植体植入后唇侧颈缘出现裂开性骨缺损或唇侧骨板厚度小于0.5mm,采用少量自体碎骨和瑞士盖式Bio-Oss骨粉充填骨缺损后,不可吸收性钛膜覆盖植骨区,并用小膜钉固定钛膜,软组织辫充分缓冲无张力后关闭术区.愈合6个月后行二期手术,取出钛膜,测量种植体唇侧骨板的厚度.二期术后2个月进行种植修复,修复效果的观察,采用Furhauser的改良红色美学指数(Defined pink es-thetic score)观察种植体修复后的软组织美学效果.结果:18例病例中,没有一例出现伤口的裂开以及感染.放射学观察18颗种植体均获得骨结合.种植体植入时,唇侧骨板的厚度(平均0.17mm),种植二期手术,即暴露种植体取出钛膜时,测量唇侧骨板的厚度为1.5mm-3.5mm,平均2.14mm,平均增加1.91mm..13例完成永久修复,并观察1年以上,软组织美学效果,采用Furhauser的红色美学指数,PES最高得分14分,最低得分9分,平均12.15分,龈缘水平线位置平均为1.77mm,牙根区的软组织的凸度平均为1.85mm,此两项得分较高,与植骨及成骨效果有密切关系.结论:在上颌前牙区单牙种植时,采取不可吸收性钛膜引导成骨,解决种植体唇侧颈部骨板裂开性骨缺损及厚度不足效果可靠.