Apical Bone Research Articles

Preexisting Periapical Inflammatory Condition Exacerbates Tooth Extraction–induced Bisphosphonate-related Osteonecrosis of the Jaw Lesions in Mice

IntroductionSurgical interventions such as tooth extraction increase the chances of developing osteonecrosis of the jaw in patients receiving bisphosphonates (BPs) for the treatment of bone-related diseases. Tooth extraction is often performed to eliminate preexisting pathological inflammatory conditions that make the tooth unsalvageable; however, the role of such conditions on bisphosphonate-related osteonecrosis of the jaw (BRONJ) development after tooth extraction is not clearly defined. Here, we examined the effects of periapical periodontitis on tooth extraction–induced BRONJ development in mice. MethodsPeriapical periodontitis was induced by exposing the pulp of the maxillary first molar for 3 weeks in C57/BL6 mice that were intravenously administered with BPs. The same tooth was extracted, and after an 3 additional weeks, the mice were harvested for histologic, histomorphometric, and histochemical staining analyses. ResultsPulp exposure induced periapical radiolucency as shown by increased inflammatory cells, tartrate-resistant acid phosphatase–positive osteoclasts, and bone resorption. When BPs were administered, pulp exposure did not induce apical bone resorption despite the presence of inflammatory cells and tartrate-resistant acid phosphatase–positive osteoclasts. Although tooth extraction alone induced BRONJ lesions, pulp exposure further increased tooth extraction-induced BRONJ development as shown by the presence of more bone necrosis. ConclusionsOur study demonstrates that a preexisting pathological inflammatory condition such as periapical periodontitis is a predisposing factor that may exacerbate BRONJ development after tooth extraction. Our study further provides a clinical implication wherein periapical periodontitis should be controlled before performing tooth extraction in BP users in order to reduce the risk of developing BRONJ.

Marginal and apical bone stability after staged sinus floor augmentation using bone condensing implants with variable-thread design: a two-dimensional analysis

Studies on the vertical stability of augmented bone after sinus lifting differ substantially. In addition, long healing periods are usually advocated prior to implant installation. The purpose of this case series study was to evaluate the changes in bone height after sinus lifting with a bovine-derived xenograft and to evaluate the clinical outcome of bone condensing implants installed after a short healing period. Patients treated during the years 2010–2013 were re-examined using peri-apical radiographs to evaluate the changes in augmented bone height (BH) and marginal bone loss (BL). Fifty-seven of 70 eligible subjects (28 male and 29 female, mean age 56 years) attended for reassessment. Data were available for 53 sinus lifts and 105 implants installed after a mean healing period of 4.6±1.5 months. Implant survival was 99% after a mean time in function of 19±9 months. Baseline BH, BH at implant placement, and final BH were on average 3.87±1.74mm, 13.75±2.12mm, and 13.11±2.12mm, respectively (P<0.001). Mean BL was 0.51±0.65mm. Only limited resorption is to be expected after sinus lifting in the short term. A bone condensing implant can be used in the early healing phase with successful outcomes in terms of implant survival and bone adaptation.

Three-Year Clinical and Radiographic Implant Follow-up in Sinus-Lifted Maxilla With Lateral Window Technique.

The aim of this study was to evaluate retrospectively the 3-year outcome of implants placed in augmented maxillary sinuses with minimal residual alveolar bone heights (≤3 mm). A total of 28 sinus floors were augmented with xenograft, and 58 implants were placed. The outcome measures were implant success based on implant stability and the absence of periimplantitis, and marginal and apical bone resorption on periapical radiograph and prosthesis survival. Fifty-seven of 58 implants with their prostheses remained functional with a success rate of 98.28%. None of the implants showed any signs of mobility or periimplantitis. Both apical and cervical bone resorption around the implants were highest by the end of the first year. The success rate of the implants placed with staged approach in augmented maxillary sinuses with the residual alveolar bone height of ≤3 mm was high in a 3-year term. Bio-Oss is an acceptable substitute autogenous bone and can be used as an augmentation material during the maxillary sinus lift procedure.

Commentaire de l’article : « Les augmentations osseuses mandibulaires antérieures. Revue de la littérature »

The severely defective socket, in which implant placement within the remaining bone will result in a significantly off-axis implant position, precludes immediate implant placement and requires bone grafting as an initial surgical intervention. The aims of this study were to evaluate autogenous chin bone ring consolidation after the augmentation of severely defective sockets and the clinical application of these rings in the premolar–molar region with simultaneous implant placement in a one-stage procedure. Ten patients with 12 defective sockets were included. Sockets were prepared with a trephine bur. Bone rings with a tapped implant osteotomy were harvested from the chin with a larger trephine bur. Bone rings were fitted in the prepared sockets. An implant drill was used to prepare the bone apical to the ring through its central osteotomy. Implants were screwed through the rings and the apical bone. Patients were examined clinically and radiographically immediately and at 6 months postoperative. Crestal bone changes were measured and evaluated statistically. All grafted sockets showed bone healing with no significant crestal bone resorption and no infection; only one ring showed dehiscence, which healed during the follow-up period. All implants showed radiographic evidence of osseointegration. The autogenous chin bone ring augmentation technique was found to be a reliable alternative method for the management of severely defective sockets.

Simultaneous implant placement with ridge augmentation using an autogenous bone ring transplant

The severely defective socket, in which implant placement within the remaining bone will result in a significantly off-axis implant position, precludes immediate implant placement and requires bone grafting as an initial surgical intervention. The aims of this study were to evaluate autogenous chin bone ring consolidation after the augmentation of severely defective sockets and the clinical application of these rings in the premolar–molar region with simultaneous implant placement in a one-stage procedure. Ten patients with 12 defective sockets were included. Sockets were prepared with a trephine bur. Bone rings with a tapped implant osteotomy were harvested from the chin with a larger trephine bur. Bone rings were fitted in the prepared sockets. An implant drill was used to prepare the bone apical to the ring through its central osteotomy. Implants were screwed through the rings and the apical bone. Patients were examined clinically and radiographically immediately and at 6 months postoperative. Crestal bone changes were measured and evaluated statistically. All grafted sockets showed bone healing with no significant crestal bone resorption and no infection; only one ring showed dehiscence, which healed during the follow-up period. All implants showed radiographic evidence of osseointegration. The autogenous chin bone ring augmentation technique was found to be a reliable alternative method for the management of severely defective sockets.

Prevalence of Apical Bone Defects and Evaluation of Associated Factors Detected with Cone-beam Computed Tomographic Images

IntroductionCone-beam computed tomographic (CBCT) imaging has been shown to be accurate for detecting apical bone defects (ABDs). Medium field of view CBCT imaging may provide apical images of the whole oral cavity at a resolution that is sufficient to allow ABDs to be located and measured. The aim of the work presented was to calculate the prevalence of ABDs from CBCT images as well as to assess some associated factors and their measurement. MethodsOne hundred CBCT data sets with a voxel size of 0.2 mm were analyzed by 2 evaluators according to a standardized reading protocol. The number of maxillary and mandibular teeth, the presence of endodontic treatment, and the presence of ABDs associated with endodontic treatment were identified, and the presence of intraradicular posts was documented. The size of ABDs detected was measured, and they were classified according to the Cone Beam Computed Tomography Periapical Index. ResultsA total of 2368 teeth and 100 subjects were analyzed. The prevalence of ABDs in subjects was 78%; in 8.6% of the sample teeth, ABDs were present, and 38.2% of endodontically treated maxillary molars were affected by it. Endodontic treatment was significantly associated with an increased risk for the presence of an ABD (P = .0001); 40.8% of endodontically treated teeth were associated with an ABD. This rate increased to 85.9% in endodontically treated maxillary molars. Placement of a post was significantly associated with the presence of an ABD (P = .003). The most frequent lesions were those with diameters between 2 and 4 mm (39.2%). ConclusionsThere are only few studies on the prevalence of ABDs using CBCT analysis. This study in a French population shows a high prevalence of ABDs, especially on endodontically treated molars. The most effective way to exhaustively detect such defects is with CBCT imaging. Moreover, CBCT images show details of the extent of bone loss, thus providing information valuable for the therapeutic decision and details that could help with the prognosis.

Histological observations of pulpal replacement tissue in immature dog teeth after revascularization of infected pulps.

Many studies have examined the nature of tissue formed in the canals of immature necrotic teeth, following revascularization in animals and humans. While speculations have been made that regeneration of the pulp tissue might take place in the canal, the tissue has been found to be cementum-like, bone-like, and periodontal ligament-like. The purpose of this study was to histologically examine the tissue in the root canals in immature dog teeth that had been artificially infected and then revascularized. Two 4- to 5-month-old mongrel dogs with immature teeth were used in the study. In one dog, four maxillary and four mandibular anterior teeth, and in another dog, four maxillary and five mandibular anterior teeth were used in the experiment. Pulp infection was artificially induced in the immature teeth. Revascularization was performed on all teeth by disinfecting the root canals with sodium hypochlorite irrigation and triple antibiotic intracanal dressing, completed with induction of intracanal bleeding, and sealed with an MTA plug. The access cavity was restored with silver amalgam. The animals were sacrificed 3months after revascularization procedures. The revascularized teeth and surrounding periodontal tissues were removed and prepared for histological examination. Besides cementum-like, bone-like, and periodontal ligament-like tissues formed in the canals, residual remaining pulp tissue was observed in two revascularized teeth. In four teeth, ingrowth of alveolar bone into the canals was seen; presence of bone in the root canals has the potential for ankylosis. Within the limitation of this study, it can be concluded that residual pulp tissue can remain in the canals after revascularization procedures of immature teeth with artificially induced pulp infection. This can lead to the misinterpretation that true pulpal regeneration has occurred. Ingrowth of apical bone into the root canals undergoing revascularization can interfere with normal tooth eruption if ankylosis occurs.

Identifying Bone-Tipped Arrow Types in the Archaeological Record of Southern Africa: The Contribution of Use-Trace Studies

This study presents a historical review of the different types of southern African hunter-gatherer arrows employing a piece of bone situated at or near the tip of the arrow, which I call the apical bone component. The results of an extensive use-trace study of bone points and fragments thereof from twelve archaeological sites spanning the last 18,000 years show that it is possible to identify arrow types based on associated use-trace features. Five possible arrow types are identified from the archaeological sample, all dating to within the last 4000–6000 years. Using use-trace studies it is possible to identify now-missing components of the arrows, such as metal, mastic or stone inserts. Contrary to recent claims, I do not find evidence for bone-tipped arrows evolving along a continuum. Rather, some arrow types may have a much greater antiquity than previously thought.

Periapical Microsurgery: The Effect of Root Dentinal Defects on Short- and Long-term Outcome

IntroductionThe purpose of this prospective clinical study was to evaluate the clinical outcome of endodontic microsurgery on roots exhibiting the presence or absence of dentinal defects at 1-year and 3-year follow-up period. MethodsOne hundred fifty-five teeth were treated with periapical microsurgery using a modern microsurgical protocol in a private practice setting. The root apices were resected and inspected for dentinal defects with a surgical operating microscope and a 0.8-mm head diameter light-emitting diode microscope diagnostic probe light. After inspection, root-end preparations were performed using ultrasonic tips, and root-end fillings were placed. Follow-up visits occurred at 1 year and 3 years postoperatively. The primary outcome measure used was the change in the radiographic apical bone density, and the secondary outcome measure used was the absence of clinical symptoms. ResultsOf the 155 treated teeth, a total of 134 teeth were assessed at the 1-year follow-up and 127 teeth at the 3-year evaluation. In the “intact” group, 94.8% healed at 1 year, and 97.3% healed at 3 years. In the “dentinal defect” group, 29.8% healed at 1 year, and 31.5% healed at 3 years. The baseline root condition of either “dentinal defect” or “intact” showed a statistical difference in the healing outcome at both 1 and 3 years. ConclusionsThis prospective periapical microsurgery study showed a significant superior clinical outcome for intact roots when compared with roots with dentinal defects at both 1 year and at 3 years postoperatively.

Biomechanical evaluation of subcrestal dental implants with different bone anchorages

This study evaluated the biomechanical influence of apical bone anchorage on a single subcrestal dental implant using three-dimensional finite element analysis (FEA). Four different bone anchorage designs were simulated on a posterior maxillary segment using one implant with platform switching and internal Morse taper connection as follows: 2 mm subcrestal placement with (SW) or without (SO) the implant apex engaged into the cortical bone or position at bone level with anchorage only in the crestal cortical (BO) bone or with bicortical fixation (BW). Each implant received a premolar crown, and all models were loaded with 200 N to simulate centric and eccentric occlusion. The peak tensile and compressive stress and strain were calculated at the crestal cortical, trabecular, and apical cortical bone. The vertical and horizontal implant displacements were measured at the platform level. FEA indicated that subcrestal placement (SW and SO) created lower stress and strain in the crestal cortical bone compared with crestal placement (BO and BW models). The SW model exhibited lesser vertical and horizontal implant micromovement compared with the SO and BO models under eccentric loading; however, stress and strain were higher in the apical cortical bone. The BW model exhibited the lowest implant displacement. These results indicate that subcrestal placement decreases the stress in the crestal cortical bone of dental implants, regardless of apical anchorage; however, apical cortical anchorage can be effective in limiting implant displacement. Further studies are required to evaluate the effects of possible remodeling around the apex on the success of subcrestal implants.

Effect of CBCT Training Sessions in Detecting Apical Bone Defects

Effect of CBCT Training Sessions in Detecting Apical Bone Defects

Five-year outcome of bone remodelling around implants in the maxillary sinus: assessment of differences between implants placed in autogenous inlay bone blocks and in ungrafted maxilla

The placement of implants in the posterior maxillary area is considered a reliable procedure, offering recognized rehabilitative advantages. The aim of this study was to evaluate the performance of dental implants placed in the sinus floor augmented with a block autograft by comparing the outcomes over 5 years with those of dental implants positioned in non-augmented bone. This retrospective cohort study included 16 patients who had undergone prosthetic rehabilitation supported by dental implants between 2000 and 2006. One implant per patient was included and assigned to one of two predictor groups: grafted versus ungrafted maxillary sinus. Changes in marginal bone level (MBL) and apical bone level (ABL) over time, at 1, 3, and 5 years, were the primary outcome variables. Appropriate pair-wise comparison tests were performed. No significant differences were seen with regard to ABLs and among times between the grafted group (nine implants) and the ungrafted group (seven implants). Significant marginal bone resorption was found over time, primarily at the buccal aspect, in both study groups. The bone surrounding the apex of dental implants appeared stable after sinus augmentation in the grafted area. The behaviour of the two groups with regard to loss of MBLs over time was very similar.

Outcome of Er,Cr:YSGG Laser-Assisted Treatment of Teeth with Apical Periodontitis: A Blind Randomized Clinical Trial

As clinical studies conducted to explore the safety and efficacy of new procedures are considered an important focus in endodontic research, the aim of this controlled clinical study was to compare a laser-assisted endodontic treatment using an erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser and radial firing tips (RFT) versus the conventional use of 3% sodium hypochlorite and interim calcium hydroxide paste, in teeth with chronic apical periodontitis. Forty-three single-rooted and premolar teeth were randomly assigned. In group 1, teeth were prepared and irrigated with 3% sodium hypochlorite and calcium hydroxide inter-appointment dressing was applied; in group 2 teeth were prepared with saline solution and irradiated with Er,Cr:YSGG laser using RFT2 (140 μs, 37.5 mJ, 20 Hz) and RFT3 (140 μs, 62.5 mJ, 20 Hz) at the first and second appointments, respectively, four times each, moving at 2 mm/sec(-1) from apical to coronal. The primary outcome measure was change in apical bone density at 12 months, using the periapical index (PAI) for blind radiographic assessment. Thirty teeth were examined and subjected to statistical analysis, 12 in the control group and 18 in the test group. There were two treatment failures in the control group that were not included for analysis; both groups exhibited statistically significant decreases in PAI scores. The present findings suggest that for single-rooted and premolar teeth, this laser-assisted protocol can achieve predictable endodontic outcomes, comparable to conventional strategies in 1 year of follow-up.

Is there correlation between alveolar and systemic bone density?

The present study assessed the correlation between maxillomandibular alveolar bone density and systemic bone mineral density (BMD). Dual-energy X-ray absorptiometry of the anterior and posterior maxillomandibular alveolar bone, of the standard sites for the measurement of BMD (lumbar spine and femur) and the third cervical vertebra was performed on 23 middle-aged women. Periapical radiographs were also obtained, with an aluminum step-wedge as reference for the digital reading of apical bone density of the upper incisors. Spearman's correlations coefficients revealed that density in the apical region was correlated with that of the femoral neck (r = 0.433; p < 0.05); BMDs of the posterior regions of the mandible and maxilla were significantly correlated with that of the cervical vertebra (r = 0.554, p ≤ 0.01 and r = 0.423, p ≤ 0.05, respectively); and the anterior maxilla was correlated with the posterior mandible (r = 0.488, p ≤ 0.05). Bone density of the maxillary alveolar bone was significantly correlated with that of the femoral neck. Among the bone densities of the alveolar regions, only the anterior maxilla and the posterior mandible were significantly correlated. The findings suggested that bone densitometry might be individually and locally evaluated.

A Novel Technique for Osteotome Internal Sinus Lifts With Simultaneous Placement of Tapered Implants to Improve Primary Stability

A Novel Technique for Osteotome Internal Sinus Lifts With Simultaneous Placement of Tapered Implants to Improve Primary Stability

Radiographic Monitoring of Changes in Bone Height after Implant Placement in Combination with an Internal Sinus Lift without Graft Material

The objective was to investigate changes in bone height after implant placement in combination with simultaneous internal sinus lift (ISL) without graft material. For a retrospective clinical study, 101 implants placed in combination with ISL without graft were selected. The study included 66 patients (mean age 59.6 years) with radiographs from baseline (T0) and two follow-ups after mean times of 7 months (T1) and 17 months (T2). Apical changes in bone height were measured at the mesial and distal aspects of the implant. Correlation analysis was performed to identify factors affecting changes in bone height. Mean apical bone gains of 1.0 mm (mesial) and 1.7 mm (distal) were observed at T1. At T2, mean apical bone gains were 1.5 mm and 2.1 mm (distal). The change in apical bone height was significant between T0 and T1, between T0 and T2, and between T1 and T2. Rank correlation analysis revealed a significant correlation (Spearman rho: -0.2 to -0.4) between small initial bone height and a greater amount of apical bone gain. A gain in apical bone height can be expected if implants are placed in combination with ISL without graft material. Variability is high, however.

A 5‐year clinical and computerized tomographic implant follow‐up in sinus‐lifted maxillae and native bone

The present study analysed apical and marginal bone remodelling around dental implants placed in both maxillary (sinus elevated with particulated autogenous osseous graft) and corresponding native bone areas, with a follow-up of 5years. The clinical survival of implants was also observed. In this retrospective chart review, 27 patients were enrolled, with 55 dental implants inserted from 2000 to 2006, 26 of which were followed (one implant per patient); if required, patients were treated via sinus lift with autogenous bone and particulate technique. The internal controls were implants positioned in native areas beneath the sinus. Radiologic survey was assessed via computerized tomographic analysis measuring apical bone level (ABL) and marginal bone level (MBL), at 1- (T1 ), 3- (T2 ) and 5years (T3 ), around implants (buccal, b; palatal, p; mesial, m; and distal sides, d). Clinical probing depth (CPD) and clinical attachment level (CAL) for all the four peri-implant aspects were measured. Cumulative survival rate (CSR) and survival rate (SR) of implants were calculated. Significances for paired and unpaired comparisons were searched for. A significant degree of apical resorption was recorded between T1 and T3 for the mesial particulate group; again, a significant difference was discovered between the native and particulate procedures for mABL. A further feature was discovered for the particulate procedure, for which ABLs resulted negative at least for three of the aspects. Regarding MBL measurements, similar behaviours were revealed using time-comparison analysis for the two procedures at the buccal aspect. Comparisons among diameters, irrespective of the procedure, showed that resorption times for the bMBL were shorter as the diameter of the implant became wider. The implant CSR was 92% in native areas (two failures/25 implants) and 93.3% in sinuses lifted with particulate bone (two failures/30 implants). The results suggest that a protrusion of the implant apices into augmented sinus lift occurred, whereas the bone remodelling of the coronal areas was not influenced by the events in the maxillary sinus. A diameter ranging from 4 to 5mm might better guarantee a conservation of marginal peri-implant bone level compared with implants with smaller diameters.

Bone Regeneration and Collagen Fiber Orientation Around Calcium Phosphate–Coated Implants with Machined or Rough Surfaces: A Short-Term Histomorphometric Study in Dog Mandibles

The aim of this study was to compare bone formation and tissue reactions around implants with a calcium phosphate (CaP)-coated machined surface (CPMS) and a CaP-coated rough surface (CPRS) at critical-sized circumferential ridge defects in dogs after 4 and 8 weeks. All mandibular premolars were extracted bilaterally from five male mongrel dogs. After 8 weeks, circumferential marginal defects (2 mm wide and 5 mm deep) were created unilaterally using a customized drill at sites of CPMS and CPRS implant insertion. Four weeks later, the contralateral side was prepared using the same protocol. The dogs were sacrificed 4 weeks later. Specimens were analyzed histologically and histomorphometrically. Both CPMS and CPRS implants showed successful osseointegration in the apical bone area (without defects) regardless of the observation period (4 or 8 weeks). All circumferential defects were incompletely filled and osseointegration was limited at the apical area of the defect. In the unfilled defect area, collagen fibers were arranged perpendicular or oblique to the exposed implant surfaces, especially on CPRS implants. Within the limits of this study, CPMS and CPRS implants showed no statistically significant differences in osseointegration and bone regeneration in circumferential defects, along with the unique feature of collagen fibers arranged perpendicular or oblique to the exposed implant surfaces.

Efficacy of Er,Cr:YSGG laser with endodontical radial firing tips on the outcome of endodontic treatment: blind randomized controlled clinical trial with six-month evaluation

Clinical reports stating the efficacy of novel root canal disinfection protocols are an important focus in endodontic research. This blind randomized clinical trial assessed the clinical efficacy of the erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser radial firing tips (RFT) versus the concomitant use of 3% sodium hypochlorite and interim calcium hydroxide paste in necrotic teeth with chronic apical periodontitis. We hypothesized to find similar or improved bone healing in the laser-assisted endodontic treatment. Thirty-six anterior and premolar teeth were randomly assigned. In group 1, teeth were prepared with 3% sodium hypochlorite for irrigation and calcium hydroxide as inter-appointment dressing; in group 2, teeth were prepared with saline solution and irradiated with Er,Cr:YSGG laser using RFT2 (140μs, 37.5mJ, 20Hz) and RFT3 (140μs, 62.5mJ, 20Hz) in the first and second appointment, respectively, four times each, moving at 2mms(-1) from apical to coronal. The primary outcome measure was changed in apical bone density at 6months, using the periapical index (PAI) for blind radiographic evaluation. Twenty-nine patients were examined and subjected to statistical analysis, 12 in group 1 and 17 in group 2. There was one treatment failure in group 1. Both groups gave similar outcomes exhibiting statistically significant decreases in PAI scores.

A Prospective Randomized Controlled Study of Mineral Trioxide Aggregate and Super Ethoxy–Benzoic Acid as Root-end Filling Materials in Endodontic Microsurgery

IntroductionThe purpose of the present study was to evaluate the clinical outcomes of endodontic microsurgery when super ethoxy-benzoic acid (Super EBA; Harry J. Bosworth, Skokie, IL) and mineral trioxide aggregate (MTA) were used as root-end filling materials in a prospective randomized controlled study. MethodsOf the 388 teeth eligible for endodontic microsurgery, 128 teeth were excluded from the study, and 260 teeth were randomly assigned to either the Super EBA group or the MTA group with equal numbers using the “minimization method.” Endodontic microsurgical procedures were performed according to the Yonsei protocol reported in a previous study and were carried out by a single operator. The patients were followed up at 3, 6, and 12 months. The primary outcome measure was the change in the apical bone density at 12 months, and the secondary outcome measures were the presence of clinical symptoms or abnormal findings at 12 months. ResultsA total of 192 teeth were examined at the 12-month follow-up; 102 teeth were in the Super EBA group, and 90 were in the MTA group. The overall success rate was 94.3%, with a success rate of 95.6% (86/90 teeth) for MTA and 93.1% (95/102 teeth) for Super EBA. The statistical analysis of the success rate results did not show any significant difference between the groups (P = .472). ConclusionsIn this prospective randomized controlled study, there was no significant difference in the clinical outcomes of endodontic microsurgery when Super EBA and MTA were used as root-end filling materials.