Histologic evaluation of the use of membrane, bone graft, and MTA in apical surgery

The impact of bone grafting with/without barrier membrane placement on the outcome of apical surgery: A systematic review and meta-analysis

BACKGROUND

Regenerative techniques are increasingly being advocated in endodontic apical surgery (AS) to enhance the healing of periapical lesions. Various grafting and membrane materials are employed as adjuncts to modern AS.

OBJECTIVES

This systematic review aimed to answer the following PICO question: In patients with apical periodontitis (P) what is the impact of bone grafting with/without barrier membrane materials (I) compared with surgery without grafting materials (C) on the outcome of AS evaluated clinically and radiographically (O).

METHODS

A systematic search was conducted in four databases (Embase, Web of Science, PubMed and Cochrane Central Register of Controlled Trials) until 1 August 2023. Google Scholar was also manually searched. Studies with a prospective randomized design were included. Cochrane risk-of-bias (RoB) tool 2.0 assessed bias. Two independent reviewers performed the study selection, data extraction and appraisal of studies. Meta-analysis was performed using R3.5.1 software.

RESULTS

From the identified 2582 studies, eight randomized clinical trials were included for meta-analysis. Two studies had low RoB, while six had some concerns. Analysis revealed significantly better outcomes when surgery involved bone regeneration techniques than conventional surgery (OR = 2.18, 95% CI: 1.32-4.31, p = .004). Subgroup analyses on individual grafts (OR = 0.22, 95% CI: -0.99 to 1.44, p = .720) (OR = -0.09, 95% CI: -1.42 to 1.23, p = .885) and membranes (OR = -1.09, 95% CI: -2.94 to 0.76, p = .247) and their combinations (OR = 0.03, 95% CI: -1.50 to 1.55, p = .970) did not yield any significant results. The type of membrane used did not significantly impact the outcome (OR = -1.09, 95% CI: -2.94 to 0.76, p = .247) nor did altering the combination of graft/membrane.

DISCUSSION

This systematic review examined the effects of bone grafting with/without membrane placement on the outcome of AS. It highlights the potential advantages of regenerative techniques and the need for further research in this area.

CONCLUSIONS

Based on current evidence, bone grafting with/without barrier membrane placement significantly improves healing after AS. Subgroup analysis of resorbable membranes or grafting did not significantly influence the outcome. The combination of membrane and graft was also not significant. Future well-designed, randomized controlled trials in this area are essential before these materials can be recommended for routine use to enhance healing outcomes in AS.

REGISTRATION

PROSPERO (CRD42021255171).

Autologous concentrated growth factor mediated accelerated bone healing in root-end microsurgery: A multicenter randomized clinical trial

Introduction

Concentrated growth factor (CGF) is a new-generation autologous platelet concentrate that promotes tissue regeneration and has anti-inflammatory properties. This randomized multicenter trial aimed to evaluate the effects of CGF on bone healing in combination with root-end microsurgery.

Methods

Healthy adult patients indicated for root-end microsurgery were randomly assigned to either the CGF or control (no CGF implantation) groups. CGF was implanted into the bone cavity after root-end filling with mineral trioxide aggregate. Clinical and periapical radiographic evaluations were conducted at 1, 3, 6, and 12 months postoperatively, with follow-up cone-beam computed tomography (CBCT) at 6 months. The lesion volume reduction rate was calculated based on data from the preoperative and follow-up CBCT images.

Results

A total of 24 patients were enrolled. The treatment success rate was 91.7% and 83.3% on 12-month periapical radiography and 6-month CBCT, respectively, without a significant difference between the two groups. The lesion volume reduction rate in the CGF group (75.6%) was significantly higher than that in the control (61.0%) group.

Conclusions

Autologous CGF in conjunction with root-end microsurgery accelerated lesion reduction as observed on CBCT. Administering autologous blood products to stimulate healing in addition to removing the source of infection appears to be a promising treatment option for root-end microsurgery.

Treatment-Related Factors Affecting the Success of Endodontic Microsurgery and the Influence of GTR on Radiographic Healing-A Cone-Beam Computed Tomography Study

The primary objective of this retrospective study was to assess the correlation between treatment-related factors (resection angle, depth of retrograde filling, length of resected root and use of guided tissue regeneration-GTR) evaluated using cone-beam computed tomography (CBCT) scans and the treatment outcomes of endodontic microsurgery (EMS). The secondary purpose of this research was to evaluate the influence of the GTR technique on the radiographic healing state, taking into account the initial parameters of periapical lesions. In 161 cases, the local factors (volume of a lesion, bone destruction pattern, presence/absence of cortical bone destruction) were measured using preoperative CBCT images before undergoing EMS. At least one year after surgery, the outcome of EMS was classified as a success or a failure (based on radiographic and clinical criteria). Using postoperative CBCT, treatment-related factors (resection angle, depth of retrograde filling, and length of resected root) were measured. Additionally, the status of radiographic healing was evaluated (in accordance with modified PENN 3D criteria). Eighteen cases (11.18%) were classified as failures, and 143 were classified as successes (88.82%). Univariate analysis showed that there was no statistically significant influence of treatment-related factors on the healing outcome of EMS. An exact Fischer's test showed the significant impact of GTR on radiographic healing (P < 0.001) in apical lesions (P < 0.001), lesions with a volume between 100 mm3 and 450 mm3 (P < 0.009) and over 450 mm3 (P < 0.001), lesions with the destruction of one plate (P < 0.001), and lesions with the destruction of two plates (through and through) (P = 0.022). The use of GTR in apical lesions, lesions with volumes over 100 mm3, and lesions with the destruction of at least one plate is significantly associated with better radiographic healing.

Biocompatibility and osteogenic potential of mineral trioxide aggregate mixed with hydrophilic synthetic polymer: An in vitro and in vivo study

This study aimed to investigate in vitro biologic properties of mineral trioxide aggregate (MTA) mixed with 3% PVA (MTA-3% PVA) and in vivo dental pulp responses to direct capping in comparison with MTA mixed with distilled water (MTA-DW). Cell proliferation and osteogenic differentiation in culture of human dental pulp cells (hDPCs), and pH changes were evaluated. Pulps in 24 mandibular premolars of four 9-month-old beagle dogs were mechanically exposed and direct pulp capping was performed. Histological specimens were scored according to the degree of mineralization. MTA-3% PVA showed similar cell proliferation and similar or superior osteogenic differentiation of hDPCs compared with MTA-DW. All specimens were associated with calcified bridge formation and there were no significant differences in mineralization scores between the groups (p>0.05). The results suggested that MTA-3% PVA exhibited favorable biocompatibility and osteogenic differentiation in vitro compared with MTA-DW. Furthermore, both groups demonstrated similar results when used as pulp-capping agents in vivo.

Factors Affecting the Success of Endodontic Microsurgery: A Cone-Beam Computed Tomography Study

The purpose of this retrospective study was to verify preoperative local parameters of periapical lesions evaluated on cone-beam computed tomography (CBCT) scans as a potential prognostic factor in endodontic microsurgery (EMS). Among 89 cases, local factors (dimensions of lesion, bone destruction pattern, presence/absence of cortical bone destruction, height of buccal bone plate, apical extend of root canal filling, presence/absence of communication with anatomical cavities, type of lesion restriction) were measured on preoperative CBCT images before EMS. At least one year after surgery, the outcome of EMS was classified as a success or a failure. Ten cases (11.24%) were classified as a failure and 79 as a success (88.76%). Symptomatic lesions (OR = 0.088 (95% CI 0.011-0.731); p = 0.024), apicomarginal lesions (OR = 0.092 (0.021-0.402); p = 0.001) and an association with molar teeth (OR = 0.153 (0.032-0.732); p = 0.019) were found as negative predictive factors in the univariate analysis, whereas large apicocoronal dimension (OR = 0.664 (0.477-0.926); p = 0.016), apicomarginal lesions (OR = 0.058 (0.006-0.55); p = 0.013), and an association with molar teeth (OR = 0.047 (0.003-0.869); p = 0.04) were identified as negative predictive factors in the multivariate analysis model. Symptomatic lesions, apicomarginal lesions, lesions associated with molar teeth and large apicocoronal dimensions are significantly associated with the failure of EMS.

Guided Tissue Regeneration in Surgical Endodontic Treatment: Case Report and Literature Review

Background/Aim: Guided tissue regeneration is widely used in endodontic surgery. The aim is to aid in the healing process and bone regeneration and provide more successful and predictable outcomes.

Case report: This case report describes the successful treatment of an endodontic-periodontal lesion (with primary endodontic involvement), including root canal retreatment and endodontic surgery with the use of GTR (collagen absorbable membrane-xenogeneic bone graft). CBCT examination was used to aid in diagnosis and in the follow-up examination after two years to provide additional confirmation of the healing process. An extensive literature review was undertaken focusing on clinical studies that assessing the added benefit of GTR in surgical endodontics. The clinical and radiographic examinations showed uneventful healing and the reconstruction of the buccal plate and periapical area. The patient remained asymptomatic throughout the entire two years period after surgical intervention. A literature review concluded that lesion type, lesion size and the selection of the biomaterial are important factors that influence the outcome of GTR in comparison control groups. A favorable outcome was found in cases of large periapical lesions (>10mm), through-through lesions and with the use of an absorbable membrane, with or without a bone graft.

Conclusions: GTR is thought to provide an added benefit in bone regeneration and the healing process in specific cases. The outcomes in the case report are consistent with the conclusions of literature review.

Analysis of bone formation and membrane resorption in guided bone regeneration using deproteinized bovine bone mineral versus calcium sulfate

Guided Bone Regeneration (GBR) is a technique based on the use of a physical barrier that isolates the region of bone regeneration from adjacent tissues. The objective of this study was to compare GBR, adopting a critical-size defect model in rat calvaria and using collagen membrane separately combined with two filling materials, each having different resorption rates. A circular defect 8 mm in diameter was made in the calvaria of Wistar rats. The defects were then filled with calcium sulfate (CaS group) or deproteinized bovine bone mineral (DBBM group) and covered by resorbable collagen membrane. The animals were killed 15, 30, 45 and 60 days after the surgical procedure. Samples were collected, fixed in 4% paraformaldehyde and processed for paraffin embedding. The resultant sections were stained with H&E for histological and histomorphometric study. For the histomorphometric study, the area of membrane was quantified along with the amount of bone formed in the region of the membrane. Calcium sulfate was reabsorbed more rapidly compared to DBBM. The CaS group had the highest percentages of remaining membrane at 15, 30, 45 and 60 days, compared to the DBBM group. The DBBM group had the highest amount of new bone at 45 and 60 days compared to the CaS group. Based on these results, it was concluded that the type of filling material may influence both the resorption of collagen membrane and amount of bone formed.

In vivo biocompatibility and biomineralization of calcium silicate cements

A new mineral trioxide aggregate (MTA) material has been developed with a modified composition that requires investigations to support its clinical use. This study evaluated the biocompatibility and biomineralization of this new MTA material and compared it with that of two other MTA cements over time. Tubes containing materials (or empty tubes as controls) were inserted into the subcutaneous tissues of 40 rats. On days 7, 15, 30, 60, and 90, the tubes were removed with the surrounding tissues, which were either stained with haematoxylin and eosin or von Kossa for further analyses or unstained for observation under polarized light. On days 7 and 15, moderate inflammation was observed in most specimens, and the fibrous capsule was thick. On day 30, there was mild inflammation in all groups, and the fibrous capsule was thin. On days 60 and 90, there was mild inflammation in the material groups, while the control group showed no inflammation, although no statistically significant difference between the groups was observed and the fibrous capsule was thin. All material groups showed structures that stained with von Kossa and could be observed under polarized light; this was not found for the control. In conclusion, the new MTA material had biocompatibility and biomineralization properties similar to those of the two existing MTA materials.

Mineral trioxide aggregate and other bioactive endodontic cements: an updated overview - part II: other clinical applications and complications

Mineral trioxide aggregate (MTA) is a dental material used extensively for vital pulp therapies (VPT), protecting scaffolds during regenerative endodontic procedures, apical barriers in teeth with necrotic pulps and open apices, perforation repairs as well as root canal filling and root-end filling during surgical endodontics. A number of bioactive endodontic cements (BECs) have recently been introduced to the market. Most of these materials have calcium and silicate in their compositions; however, bioactivity is a common property of these cements. These materials include the following: BioAggregate, Biodentine, BioRoot RCS, calcium-enriched mixture cement, Endo-CPM, Endocem, EndoSequence, EndoBinder, EndoSeal MTA, iRoot, MicroMega MTA, MTA Bio, MTA Fillapex, MTA Plus, Neo MTA Plus, Ortho MTA, Quick-Set, Retro MTA, Tech Biosealer, and TheraCal LC. It has been claimed that these materials have properties similar to those of MTA but without the drawbacks. In Part I of this review, the available information on the chemical composition of the materials listed above was reviewed and their applications for VPT was discussed. In this article, the clinical applications of MTA and other BECs will be reviewed for apexification, regenerative endodontics, perforation repair, root canal filling, root-end filling, restorative procedures, periodontal defects and treatment of vertical and horizontal root fractures. In addition, the literature regarding the possible drawbacks of these materials following their clinical applications is reviewed. These drawbacks include their discolouration potential, systemic effects and retreatability following use as a root filling material. Based on selected keywords, all publications were searched regarding the use of MTA as well as BECs for the relevant clinical applications. Numerous publications were found regarding the use of BECs for various endodontic applications. The majority of these investigations compared BECs with MTA. Despite promising results for some materials, the number of publications using BECs for various clinical applications was limited. Furthermore, most studies had several methodological shortcomings and low levels of evidence.

Effect of bismuth oxide on white mineral trioxide aggregate: chemical characterization and physical properties

AIM

To assess the effect of bismuth oxide (Bi2 O3 ) on the chemical characterization and physical properties of White mineral trioxide aggregate (MTA) Angelus.

METHODOLOGY

Commercially available White MTA Angelus and White MTA Angelus without Bi2 O3 provided by the manufacturer especially for this study were subjected to the following tests: Rietveld X-ray diffraction analysis (XRD), energy-dispersive X-ray analysis (EDX), scanning electron microscopy (SEM), compressive strength, Vickers microhardness test and setting time. Chemical analysis data were reported descriptively, and physical properties were expressed as means and standard deviations. Data were analysed using Student's t-test and Mann-Whitney U test (P = 0.05).

RESULTS

Calcium silicate peaks were reduced in the diffractograms of both hydrated materials. Bismuth particles were found on the surface of White MTA Angelus, and a greater amount of particles characterized as calcium hydroxide was observed by visual examination on White MTA without Bi2 O3 . The material without Bi2 O3 had the shortest final setting time (38.33 min, P = 0.002), the highest Vickers microhardness mean value (72.35 MPa, P = 0.000) and similar compressive strength results (P = 0.329) when compared with the commercially available White MTA Angelus containing Bi2 O3 .

CONCLUSION

The lack of Bi2 O3 was associated with an increase in Vickers microhardness, a reduction in final setting time, absence of Bi2 O3 peaks in diffractograms, as well as a large amount of calcium and a morphology characteristic of calcium hydroxide in EDX/SEM analysis.

Root Reconstructed with Mineral Trioxide Aggregate and Guided Tissue Regeneration in Apical Surgery: A 5-year Follow-up

Apical surgery should be considered as the last treatment option and employed when conventional endodontic treatment does not provide the expected result. In teeth undergoing apical surgery, the type of retrograde filling material is one of the factors interfering with the repair of periapical tissues. The material in intimate contact with the periapical tissues plays a fundamental role in the repair process. Several materials have been studied and indicated for use in apical surgery procedures, but the mineral trioxide aggregate (MTA) is still the most frequently used one. Guided tissue regeneration (GTR) techniques have been proposed as an adjunct to apical surgery to enhance bone healing. Here is reported a clinical case in which apical surgery was performed in conjunction with MTA-based root reconstruction of the maxillary right second incisor. After the apical surgery, a root-end cavity was prepared at the vestibular face of the involved tooth and filled with MTA. A bovine bone graft and a cortical collagen membrane were placed on the bone defect. After 5 years, clinical and radiographic assessments showed that the treatment was successful. It may be concluded that MTA presents favorable characteristics in adverse conditions and can be used in conjunction with GTR in cases involving root reconstruction.

Evaluation of dental socket healing after using of porous titanium granules: Histologic and histomorphometric assessment in dogs

Background:

Different methods have been suggested to preserve bone architecture following traumatic events such as teeth extraction. The purpose of the study was to histologically and histomorphometrically evaluate the dental socket healing after applying porous titanium granules (PTG) in dogs.

Materials and Methods:

Four healthy male dogs were involved in the present 6-weeks experimental animal study. Three sockets were surgically created in each side of dog's mandible. One of the sockets in one side was randomly filled by PTG and covered by a resorbable membrane (Tigran + membrane group). Another socket was left unfilled and just covered by the same membrane (membrane group) and the last one was left unfilled and uncovered as the control group. The dogs were killed at two time intervals (2 weeks and 6 weeks, two dogs at each time point). All samples were histologically evaluated under an optical microscope for a new bone formation. Data were analyzed by SPSS ver. 16 and Kruskal–Wallis and Mann–Whitney tests were used to compare data in different groups (α = 0.05).

Results:

There was a significant difference between the Tigran + membrane and the control group in 2 and 6 weeks in the mean amount of total regenerated bone (P < 0.05). The mean amounts of woven, lamellar, and total regenerated bone showed significant differences between 2 weeks and 6 weeks for all three groups (P < 0.05).

Conclusions:

It can be assumed that the use of Tigran bone substitute with membrane can promote the bone regeneration in bone defects.

Autogenous bone combined with anorganic bovine bone for maxillary sinus augmentation: analysis of the osteogenic potential of cells derived from the donor and the grafted sites

OBJECTIVES

This study aimed to comparatively evaluate the in vitro osteogenic potential of cells obtained from the mandibular ramus (MR, autogenous bone donor site) and from the maxillary sinus (MS) bone grafted with a mixture of anorganic bovine bone (ABB) and MR prior to titanium implant placement (MS, grafted implant site).

MATERIAL AND METHODS

Cells were obtained from three patients subjected to MS floor augmentation with a 1 : 1 mixture of ABB (GenOx Inorg(®) ) and MR. At the time of the sinus lift procedure and after 8 months, prior to implant placement, bone fragments were taken from MR and MS, respectively, and subjected to trypsin-collagenase digestion for primary cell culturing. Subcultured cells were grown under osteogenic condition for up to 21 days and assayed for proliferation/viability, osteoblast marker mRNA levels, alkaline phosphatase (ALP) activity and calcium content/Alizarin red staining. ALP activity was also determined in primary explant cultures exposed to GenOx Inorg(®) (1 : 1 with MR) for 7 days. Data were compared using either the Mann-Whitney U-test or the Kruskal-Wallis test.

RESULTS

MS cultures exhibited a significantly lower osteogenic potential compared with MR cultures, with a progressive increase in cell proliferation together with a decrease in osteoblast markers, reduced ALP activity and calcium content. Exposure of MR-derived primary cultures to GenOx Inorg(®) inhibited ALP activity.

CONCLUSION

These results suggest that the use of GenOx Inorg(®) in combination with MR fragments for MS floor augmentation inhibits the osteoblast cell differentiation at the implant site in the long term.

Effects of bone graft materials on the microhardness of mineral trioxide aggregate

INTRODUCTION

Large through-and-through lesions have been reported to heal faster and better when filled with bone graft material at the time of an apicoectomy. It is unknown what effect these have on retrograde filling materials such as white mineral trioxide aggregate (WMTA). In this study, the null hypothesis was tested that the presence of bone graft materials does not affect the microhardness of WMTA.

METHODS

Freshly mixed WMTA was condensed into acrylic cylinders and preincubated aerobically at 37°C for 1 hour. Cylinders were immersed in simulated body fluid in close proximity to graft materials: xenograft (Bio-Oss, n = 60), freeze-dried bone allograft (MinerOss, n = 60), demineralized freeze-dried bone allograft (OraGraft, n = 40), and allograft (Puros, n = 60). Knoop microhardness of half the samples in each group was evaluated after 2 weeks of incubation and the remainder at 4 weeks. The values for each group were then compared with 2-way analysis of variance and Bonferroni post hoc tests.

RESULTS

WMTA microhardness values for Bio-Oss, MinerOss, and Puros groups were lower than those for OraGraft and control groups regardless of incubation period (P < .001); values for the OraGraft group were higher than those for the control group at 2 weeks (P < .001), with no difference at 4 weeks. Microhardness values were higher at 4 weeks compared with 2 weeks for MinerOss (P < .05), OraGraft (P < .01), and control (P < .001), with no differences for Bio-Oss and Puros groups. The null hypothesis was rejected.

CONCLUSIONS

Demineralized and mineralized graft materials appear to have a differential effect on the microhardness of WMTA.

The use of regenerative techniques in apical surgery: A literature review

Apical surgery has become a standard of care for tooth maintenance if conventional endodontic retreatment is not possible or associated with risks. However, in certain situations, the outcome of apical surgery may be compromised due to the extent or location of the periapical or periradicular lesions. The present review article including clinical and experimental studies reports and discusses the outcome of regenerative techniques (RT) in conjunction with apical surgery, with regard to the type of periradicular lesions:

APICAL LESIONS

The majority of studies have shown no benefit for healing in test sites treated with RT compared to control sites treated without RT. The use of a radio-opaque bone filler/substitute may even compound the radiographic interpretation of periapical healing. Currently, the use of RT for lesions <10 mm limited to the apical area is not warranted.

THROUGH-AND-THROUGH LESIONS

All reviewed studies demonstrated a better outcome for test sites with RT compared to the control sites without RT; hence the use of RT for treatment of tunnel lesions in apical surgery is recommended.

APICO-MARGINAL LESIONS

All clinical studies assessed cohorts without controls, and, therefore, no firm conclusion about the benefit of RT for treatment of apico-marginal lesions in conjunction with apical surgery can be drawn. However, the experimental animal studies have shown that healing of teeth with apico-marginal lesions appears to benefit from RT.