Bone Height Changes Research Articles

Comparison of three approaches for treating the bony access window in lateral sinus floor elevation: a retrospective analysis

The aim of this study was to retrospectively determine the effects of applying different treatment methods to the bony access window on the healing outcomes in lateral sinus floor elevation (SFE). Lateral SFE with implant placement was performed in 131 sinuses of 105 patients. The following three treatment methods were applied to the bony access window: application of a collagen barrier (group CB), repositioning the bone fragment (group RW) and untreated (group UT). Radiographic healing in the window area, augmented bone height changes and marginal bone level changes were examined. Mixed logistic and mixed linear models were analyzed. Over 4.3 ± 1.4 years of follow-up, the implant survival rate was 100% in groups CB and UT, and 96.9% in group RW. The treatment applied to the window did not significantly influence the radiographic healing in the window area, augmented bone height changes or marginal bone level changes (p > 0.05). The healed window areas had generally flat morphologies and were fully corticalized. The mean changes in the augmented bone were less than 1.5 mm in all groups. Marginal bone level changes were minimal. In conclusion, Healing outcomes were not different among three different methods to treat the bony access window in lateral SFE.

Mandibular molar protraction: A comparison between fixed functional appliances and temporary anchorage devices.

This study aimed to compare the efficiency of temporary anchorage devices (TADs) and fixed functional appliances (FFAs) for mandibular molar protraction. Orthodontic records of 1050 consecutively treated patients with molar protraction were screened. Thirty-six records (22 females and 14 males; mean age, 17.4 years) were divided into two groups: TAD (21 subjects with 25 edentulous spaces) and FFA (15 subjects with 24 edentulous spaces). The primary outcome measure was the efficiency of protraction [magnitude and time required for protraction (rate) and anchor loss (AL)]. The secondary outcomes involved measuring the type of tooth movement (TOTM), external apical root resorption (EARR), alveolar bone height change (ABHC), alveolar bone width change (ABWC) and appliance failure. The rate of tooth movement was significantly higher for FFAs (0.83 ± 0.35 mm/month) versus TADs (0.49 ± 0.2 mm/month) (P = .005). Total treatment duration was less for FFAs (34.78 ± 8.1 months) versus TADs (47.72 ± 13.94 months) (P = .002). TOTM was similar for both (P = .909). EARR was 1.42 ± 1.38 mm for TAD and 1.25 ± 0.88 mm for FFA (P = .81). ABHC increased in the FFA group (1.01 ± 3.62 mm) and decreased for the TAD group (0.68 ± 1.66 mm). ABWC increased for both TAD (1.81 ± 1.73 mm) and FFA (1.75 ± 1.35 mm). The failure rate was 50% for FFAs and 33% for TADs. Both systems provided translation of lower molars with comparable anchorage control. However, FFAs were more efficient than TADs for lower molar protraction.

Assessment of the application of a novel three-dimension printing individualized titanium mesh in alveolar bone augmentation: A retrospective study.

To assess the clinical and radiographic outcomes of alveolar ridge augmentation using a novel three-dimensional printed individualized titanium mesh (3D-PITM) for guided bone regeneration (GBR). Preoperative cone-beam computed tomography (CBCT) was used to evaluate alveolar ridge defects, followed by augmentation with high-porosity 3D-PITM featuring circular and spindle-shaped pores. Postoperative CBCT scans were taken immediately and after 6 months of healing. These scans were compared with preoperative scans to calculate changes in bone volume, height, and width, along with the corresponding resorption rates. A statistical analysis of the results was then conducted. A total of 21 patients participated in the study, involving alveolar ridge augmentation at 38 implant sites. After 6 months of healing, the average bone augmentation volume of 21 patients remained at 489.71 ± 252.53 mm3, with a resorption rate of 16.05% ± 8.07%. For 38 implant sites, the average vertical bone increment was 3.63 ± 2.29 mm, with a resorption rate of 17.55% ± 15.10%. The horizontal bone increment at the designed implant platform was 4.43 ± 1.85 mm, with a resorption rate of 25.26% ± 15.73%. The horizontal bone increment 2 mm below the platform was 5.50 ± 2.48 mm, with a resorption rate of 16.03% ± 9.57%. The main complication was exposure to 3D-PITM, which occurred at a rate of 15.79%. The novel 3D-PITM used in GBR resulted in predictable bone augmentation. Moderate over-augmentation in the design, proper soft tissue management, and rigorous follow-ups are beneficial for reducing the graft resorption and the incidence of exposure.

Five years of radiographic evaluation for the peri-implant bone changes of all-on-four implant prostheses constructed from different framework materials using different digital construction techniques

BackgroundThere is insufficient evidence recommending a framework material and a CAD/CAM manufacturing technique for mandibular implant-supported prostheses. The study objective was to evaluate the clinical application of different materials and construction techniques used for mandibular All-on-4 prosthesis on circumferential peri-implant bony changes after 5 years.MethodsThirty-six male patients with all-on-4 mandibular implant-supported prostheses were recalled and divided into three groups. Group PK (patients with frameworks milled from PEEK blocks), Group PSM (patients with frameworks milled from soft metal blocks), and Group SLM (patients with frameworks constructed with additive manufacturing; selective laser melting). The circumferential bone level on all implant faces was assessed with a CBCT. Two-way repeated measures ANOVA was used to compare vertical bone loss (VBL) and horizontal bone loss (HBL) between different groups, implant positions, and observation times followed by Tukey’s multiple comparisons.ResultsFor all observation times, there was a significant difference in VBL between groups for both anterior and posterior implants (P < .001). For anterior implants, group PSM showed the lowest VBL while group PK showed the highest for anterior and posterior implants. For all groups, HBL significantly increased after 5 years for both anterior and posterior implants (P < .001). For anterior implants, group PSM showed the highest HBL. For posterior implants, group PK and SLM showed the highest.ConclusionWithin the study’s limitations, mandibular implant-supported fixed frameworks fabricated with either milling from PEEK or soft metal blocks, or additive manufacturing (laser melting technology) exhibited significant vertical and horizontal bone height changes after 5 years.Clinical Trial Registry Number(NCT06071689) (11/10/2023).

Bone volume and height changes for lateral window sinus floor elevation using two types of deproteinized bovine bone mineral: A retrospective cohort study of 1-4 years.

To compare bone volume and height changes of two types of deproteinized bovine bone mineral (DBBM) for lateral window sinus floor elevation (LSFE) with simultaneous implant placement. This retrospective cohort study involved 72 patients who underwent LSFE using low-temperature sintered cancellous bone-derived DBBM (C-DBBM) or high-temperature two-step sintered epiphyseal-derived DBBM (E-DBBM). Cone-beam computed tomography (CBCT) was acquired preoperatively, immediately postoperatively, 6 months and 1-4 years post-surgery. Bone volume (BV), apical bone height (ABH), endo-sinus bone gain (ESBG), and crestal bone level (CBL) were evaluated through three-dimensional fitting and superimposition. Linear mixed models (LMM) were employed to analyze factors influencing the reduction of BV (ΔBV) and ESBG (ΔESBG). The E-DBBM group showed no significant change in BV 1-4 years post-surgery, while the C-DBBM group demonstrated a significant reduction (p = .006) with volume stability of 85.86%. Bone height in the E-DBBM group increased at 6 months and subsequently decreased at 1-4 years (p = .003). In the C-DBBM group, it decreased at 6 months (p = .014), then further decreased at 1-4 years (p = .001). ΔESBG was lower in the E-DBBM group than the C-DBBM group from immediate postoperative to 1-4 years (p = .009). LMM showed graft material type was the primary factor influencing ΔBV (p = .026) and ΔESBG (p = .003). Within the limitations of this study, both types of DBBM could achieve favorable clinical outcomes. E-DBBM demonstrated enhanced stability in maintaining bone volume and height.

Effect of alveolar ridge preservation at periodontally compromised molar extraction sockets: A retrospective cohort study.

To date, the clinical evidence regarding the effectiveness of alveolar ridge preservation (ARP) in restricting alveolar bone height and width change after extraction at periodontally compromised molar extraction sockets still remains controversial. This retrospective cohort study aims to evaluate the effect of ARP in molars extracted for periodontal reasons. Retrospective data were collected from patient electronic records from January 2019 to December 2023. Patients with Stage III/IV periodontitis who underwent extraction of molars for periodontal reasons were screened for eligibility. The outcomes included the horizontal and vertical dimensions of alveolar bone. The need for additional augmentation procedure during implantation was also evaluated. A linear regression model was used to adjust for known confounders. A total of 80 sockets were included in this study, of which 27 sockets received ARP therapy after extraction while 53 sockets experienced natural healing (NH). ARP resulted in significantly less bone height change in the periodontally compromised molar sites compared to the NH group (p<0.001). In sockets displaying a height disparity of >2mm between the buccal and palatal/lingual walls, the ARP group exhibited advantageous outcomes in terms of ridge width change, surpassing the NH group (p=0.004). Moreover, the percentage for additional augmentation was significantly reduced in the ARP compared to the NH group (p=0.006). Age, sex, smoking, jaw, location, and buccal wall thickness did not show any significant effect on bone height change. ARP had benefits on limiting ridge resorption subsequent to molar extraction for periodontal reasons.

Effect of Ridge Splitting of Mandibular Knife Edge Ridges with Two-implant Retained Overdenture with Locator Attachments on Peri-implant Bone Level and Posterior Ridge Resorption: A One-year Preliminary Study.

This study was conducted to evaluate peri-implant bone height changes and posterior ridge resorption by using two-implant retained polyetheretherketone (PEEK) overdentures with locator attachments following expansion of mandibular knife edge ridges by ridge splitting. Eighteen patients were selected for ridge splitting followed by expansion, implant placement, and bone graft application. Six months later, the fabrication of PEEK overdentures retained by locator attachments was accomplished. Friedman test, Wilcoxon signed-rank test, and Spearman correlation were used to evaluate the changes over time. Peri-implant bone height loss increased significantly with the advance of time between 6 and 12 months following denture insertion. Posterior area index changes were significant over time when measured at the time of denture insertion and twelve months following denture insertion. The effect of using PEEK as overdenture base material retained with two locator attachments allowed sharing the load between the peri-implant bone anteriorly and residual ridge posteriorly in cases with ridge splitting technique. Using PEEK as an overdenture base material is a successful means of bone preservation. How to cite this article: Helmy MA, El-Shaheed NH, El Waseef FA, et al. Effect of Ridge Splitting of Mandibular Knife Edge Ridges with Two-implant Retained Overdenture with Locator Attachments on Peri-implant Bone Level and Posterior Ridge Resorption: A One-year Preliminary Study. J Contemp Dent Pract 2023;24(11):834-839.

Evaluation of Marginal Bone Height Changes in implant-supported mandibular overdenture retained with Two Different Materials of Bar Attachments.

Evaluation of Marginal Bone Height Changes in implant-supported mandibular overdenture retained with Two Different Materials of Bar Attachments.

Radiographic evaluation of alveolar bone height changes around mandibular implants with different surface treatments supporting mandibular overdenture (A split mouth comparative study )

Radiographic evaluation of alveolar bone height changes around mandibular implants with different surface treatments supporting mandibular overdenture (A split mouth comparative study )

Efficacy of autogenous particulated dentin graft for alveolar ridge preservation: A systematic review and meta-analysis of randomized controlled trials.

Autogenous particulate dentin (APD) has been used as a bone graft material for bone augmentation, but the specifics of its effect on alveolar ridge preservation (ARP) are uncertain. The aim of this study was to investigate the clinical and histomorphometric performance of APD compared with blood clot healing or other grafted materials in ARP. MEDLINE, Embase, Web of Science, Scopus and the Cochrane Library and citation databases were searched until August 2, 2023 to identify randomized controlled trials that employed APD for ARP. Two independent meta-analyses were performed based on the different control groups (Group I: blood clot healing; Group II: other grafted materials). Weighted or mean differences (MDs) and corresponding 95% confidence intervals (CIs) were calculated. The protocol was prospectively registered with PROSPERO (CRD42023409339). A total of 238 records were identified, of which ten studies with 182 participants were included. The meta-analysis indicated that APD resulted in fewer changes in horizontal ridge width (Group I: MD = 1.61, 95% CI 0.76-2.46; Group II: MD = 1.28, 95% CI 1.08-1.48) and labial bone height (Group I: MD = 1.75, 95% CI 0.56-2.94; Group II: P < .05) than the control treatments. Regarding histomorphometry, APD yielded a satisfactory proportion of vital bone area (MD = 10.51, 95% CI 4.70-16.32) and residual material area (MD = -8.76, 95% CI -12.81 to -4.71) in Group II, while there was no significant difference in Group I. Moreover, none of the secondary outcomes were significantly differed between groups. Within this study limitations, APD effectively maintained the horizontal and vertical dimensions of the extraction sockets and exhibited favorable osteogenic properties and degradation capacity. Further well-designed randomized controlled trials with larger samples and longer follow-up periods are needed to evaluate whether APD is superior to other substitutes for ARP.

EFFECT OF DENTAL IMPLANTS SURFACE TREATMENT ON MARGINAL BONE HIGHT

Statement of problem:Marginal bone changes around implant supported complete dentures is one of the most significant factor that affect the clinical success of dental implants which depends mainly on osteointegration and surface treatment. Purpose. This study aimed to assess the change in marginal bone height of two different surface treated implants retaining and supporting complete overdenture. Materials and Methods.50-60 yearsoldcompletelyedentulous patients wereselectedandand rehabilitatedwithmaxillarycomplete dentures and mandibularoverdenturesretained by twoball and socket dental implants. The implants surface treatmentsusedwereacidetch andresorbable blast media (RBM). Marginal boneheight changes wereassessed at denture insertion, after six- and twelve-monthusingconebeamcomputedtomography (CBCT). Date wascollected and Students t-test wasperformed. Results. The change of marginal bone of the acid etched and RPM implants throughout the follow up periods showed no significant statistical difference among the two type of implants at time of loading, after the 6th and 12th month. Conclusions. Acid etchedandRBM dental implants supporting and retaining complete mandibular overdentures showed significant success rates regarding the marginal bone changes during the follow up period. Clinical Implications: Guided implant placementgranting more accurate and predictable implant position while reducing the patient fear and anxiety. The marginal bone level changes were within the reported range of the literature of both acid etched and RBM dental Implants.

Radiographic comparison of atelocollagen versus deproteinized bovine bone minerals covered with a collagen membrane in alveolar ridge preservation: a retrospective study

BackgroundAtelocollagen (AC) is a low-immunogenic collagen derivative with longer degradation time, which can be a suitable material for alveolar ridge preservation (ARP). However, there are few human studies on AC using for ARP. This research aims to radiographically evaluate the efficacy of AC in comparison to deproteinized bovine bone minerals covered with a collagen membrane (DBBM/CM) in ARP.MethodsMedical records in the Implantology Department of the Hospital of Stomatology of Wuhan University were screened for patients who received flapless ARP using either AC or DBBM/CM. A total of 58 patients were included in this retrospective study. 28 patients were treated with AC, while 30 patients were used DBBM/CM. Cone-beam computed tomography (CBCT) scans were taken before extraction and after 6 months of healing. To assess the dimensional change of the extraction sockets, the scanning data were output and transferred to the digital software to measure horizontal bone width change, vertical bone height change and bone volume change in region of interest. To evaluate the bone quality of healed sockets, the bone density of virtual implants was evaluated.ResultsThe horizontal bone width changes at all five different levels showed no significant difference between the two groups. The largest horizontal bone width decrement in both groups occurred at the crest of ridge, which decreased 3.71 ± 1.67 mm in AC group and 3.53 ± 1.51 mm in DBBM/CM group (p = 0.68). At the central buccal aspect, the ridge height reduced 0.10 ± 1.30 mm in AC group, while increased 0.77 ± 2.43 mm in DBBM/CM group (p = 0.10). The vertical bone height differences between two groups showed no statistical significance. The percentages of volume absorption in AC group and DBBM/CM group were 12.37%±6.09% and 14.54%±11.21%, respectively. No significant difference in volume absorption was found (p = 0.36). The average bone density around virtual implants in AC group (649.41 ± 184.71 HU) was significantly lower than that in DBBM/CM group (985.23 ± 207.85 HU) (p < 0.001).ConclusionsARP with AC had a similar effect on limiting the dimensional alteration of alveolar ridge, when radiographically compared with DBBM/CM.

Immediate association of navicular bone height and plantar intrinsic muscle size with toe flexion task: An ultrasound-based study

BACKGROUND: Intrinsic foot muscle (IFM) dysfunction and poor foot arch are associated with various foot conditions. Toe flexor exercise (TFE) has been used to improve it; however, the immediate effects of TFE on each IFM and how it relates to changes in navicular bone height (NH) are unclear. OBJECTIVE: This study aimed to investigate acute muscle swelling in the IFM after TFE and the association between changes in NH and IFM size. METHODS: Fourteen adults participated in this study. NH and cross-sectional area (CSA) of the IFM were acquired pre and post- TFE. The CSA of the IFM, including the abductor hallucis (AbH), flexor hallucis brevis, flexor digitorum brevis, and quadratus plantae, was acquired with ultrasonography. In the TFE, each participant completed five sets of eight repetitions with maximum strength. RESULTS: The NH and CSA of all IFM significantly increased significantly post-TFE (p&lt; 0.01). Only the increase in AbH was moderately and positively correlated with the change in NH (r= 0.54, p&lt; 0.01). CONCLUSION: This study suggests that the acute swelling of AbH after TFE is associated with an immediate increase in NH, supporting the important role of AbH in the formation of foot arch.

Peri-Implant Marginal Bone Height Change and Patient’s Satisfaction Rehabilitated with Ball and OT Equator with Smart box Attachment for Retaining Mandibular Implant Overdenture

Peri-Implant Marginal Bone Height Change and Patient’s Satisfaction Rehabilitated with Ball and OT Equator with Smart box Attachment for Retaining Mandibular Implant Overdenture

The transalveolar approach with the small segmentation method for inclined maxillary sinus floor elevation: A retrospective study.

To evaluate the clinical outcome of the transalveolar approach with the small segmentation method for inclined maxillary sinus floor elevation. Sixty-one patients with an inclined maxillary sinus floor (tilt angle ≥ 10°) and insufficient residual bone height in the posterior maxilla were included and grouped according to the tilt angle of the sinus floor, with group A having patients with the tilt angle ≥ 10° and ≤ 30° and group B having patients with the tilt angle > 30°. After completing sinus membrane elevation and bone augmentation using bone substitute materials, the implants were inserted at the same appointment, and the restoration was completed after 5-6 months of osseointegration. The preoperative sinus floor level and sinus floor elevation achieved postoperatively were assessed and recorded. At pre- and post-operative timepoints, the sagittal plane of the cone beam computed tomography was used to evaluate the bone height changes at the peak, middle and valley points in the slope segment intended for implant implantation. Osseointegration was evident in all 61 patients, and the final restoration was completed with functional loading. After assessing the normality and homogeneity of variance, two-sample t-test or nonparametric tests were employed to estimate the differences in the bone height changes. The degrees of freedom (df) for this analysis were 59. The elevation attained at the middle point in groups A and B were 6.71 ± 1.38 and 5.75 ± 1.56 mm, respectively, demonstrating a significant difference (p < 0.05). Furthermore, at the peak and valley points, group A exhibited bone height changes of 5.79 ± 1.74 and 6.06 ± 1.45 mm, respectively, compared to group B with changes measuring 4.63 ± 2.18 and 5.58 ± 2.39 mm, respectively, with no significant difference in the two groups (p ≥ 0.05). The prevalence of intraoperative sinus membrane perforation was assessed using the chi-square test. It was found that four cases in group A and five cases in group B experienced sinus membrane perforation, with no significant difference in the two groups (p ≥ 0.05, df = 1). The transalveolar approach using the small segmentation method suggests a promising approach for elevating the inclined maxillary sinus floor.

The Effectiveness and Practicality of a Novel Barrier Membrane for the Open Window in Maxillary Sinus Augmentation with a Lateral Approach, with Risk Indicators for Bone Graft Displacement and Bone Height Decrease: A Prospective Study in Humans.

Maxillary sinus augmentation with a lateral approach (MSA) is a well-established treatment. In this prospective study, we evaluated risk factors for postoperative bone graft displacement and reported the clinical application of long-term resorbable L-lactic acid/-caprolactone (PLA/PCL) as a barrier membrane to cover the open window in the lateral wall in MSA. Twenty-four patients underwent MSA according to the relevant criteria; CT data obtained before and 1 week (1 w) and 5-6 months (5 m) post-MSA, bone height changes, bone height reduction rates at 1 w and 5 m post-MSA, bone graft displacement measurements, and risk factors were examined. All patients showed bone height increments (p < 0.005). However, no difference was observed between 1 w and 5 m post-MSA. Bone graft displacement was observed in eight patients; the reduction rate from 1 w to 5 m post-MSA was 8.38% ± 4.88%. Sex, septa, maxillary sinus floor-palatal bone distance, and maxillary sinus floor-maxillary ostium distance were associated with bone graft displacement (p < 0.05). The height from the maxillary sinus floor to the palatal bone and the sinus angle influenced the augmentation degree (p < 0.05). The PLA/PCL membrane is compared favorably with other membranes and may be useful as a barrier membrane for the MSA open window.

A retrospective study of alveolar bone remodelling after anterior retraction in orthodontic tooth extraction cases with clear aligners and fixed appliances.

To evaluate alveolar bone dimensions and its relationship with tooth movement (retraction, intrusion and torque) during orthodontic treatment with fixed appliance and clear aligners. Thirty-two patients were included in this retrospective clinical study. Cone beam computed tomography (CBCT) was collected before and after treatment to measure the volume of dehiscence and fenestrations in the maxillary anterior region, anterior alveolar bone thickness and height and degree of tooth movement. Rank-sum tests were used to compare the differences in alveolar bone defect volumes between clear aligners and fixed appliance, multiple linear regression analysis was used for study evaluation, and kappa statistics were used to assess internal consistency and test-retest reliability. Post-operatively, most alveolar bone defects occurred on the labial side. The incidence of bone fenestration was 23.96% in the clear aligner group and 26.18% in the fixed appliance group, which was higher than the incidence of bone dehiscence (5.21%). The labial bone height decreased by 0.272 mm, and the palatal bone height increased by 0.617 mm for every 1 mm downward intrusion of the anterior tooth apex in the fixed appliance group. In the clear aligner group, there was no significant change in the labial bone height, and the palatal bone height decreased by 0.447 mm for every 1 mm of anterior tooth retraction coronally. In the fixed appliance group, anterior tooth intrusion and retraction may have led to alveolar bone resorption by its compression at the cervical level. This study provides a three-dimensional tooth movement evaluation method by using CBCT.

Radiographic Evaluation of Bone Height Changes Around Immediately Placed Implant Retaining Mandibular Over-Denture in Atraumatic Tooth Extraction Cases.

Radiographic Evaluation of Bone Height Changes Around Immediately Placed Implant Retaining Mandibular Over-Denture in Atraumatic Tooth Extraction Cases.

Tooth-Implant-Supported Prosthetic Structures Versus Implant-Supported Restorations.

The primary aim was to compare the amount of bone height change that occurs around the tooth and the implant when having tooth-implant-supported prosthetic restorations versus bone height change that appears around implants in only implant-supported prosthetic restorations. The secondary aim was to examine the influence of various factors such as the number of teeth involved in the construction, their endodontic treatment, number of implants, the type of implantology construction, the jaw in which the construction is located, the condition of the opposite jaw, gender, age, and working time, as well as to examine whether the initial bone level influenced the amount of change in bone height itself. With a total of 50 respondents, 25 X-ray panoramic images were representing tooth-implant-supported prosthetic restorations, while the other 25 were representing implant-supported prosthetic restorations. Bone measures were taken (from enamel-cement junction/implant neck to the most apical bone point) from 2 panoramic radiographs. The first one is immediately after the implant placement and the second and the last one again in half a year up to seven years after, depending on the time when the photo was taken for each patient. The obtained difference represented the bone resorption, the bone formation, or a state without change. Influence of different factors, such as sex, age of the patient, working time, the number of teeth involved in the construction, endodontic treatment, number of implants, the type of implant construction, the jaw where the construction is located, the condition of the opposite jaw, as well as the initial bone condition, was examined. During the statistical analysis, frequency tables, basic statistical parameters, the Mann-Whitney U test, the Kruskal-Wallis Anova, Wilcoxon test, and regression analysis were used, and the results were presented in tabular form and the form of the Pareto diagram of t-values. No statistically significant difference in bone change (whether we are talking about the place of the implant (-0.359±1.009 and median value 0.000), the place of a tooth (-0.428±0.746 and median value -0,150) in tooth-implant supported restorations, or the place of the implant in case of implant-supported structures (-0,059±0,200 and median value -0,120)) was proven. When talking about the influence of other factors, by regression analysis, the number of implants was shown to be the only factor with a statistically significant influence (β=0.54; P=0.019) in a change of bone level, but only when talking about implant-supported restorations. No significant difference was proven between bone height change, neither around the tooth nor the implant in tooth-implant-supported prosthetic restorations compared to the bone height changes around the implant in only implant-supported prosthetic restorations. Among all the examined factors, the number of implants has shown to have statistically significant contribution to the amount of bone height change in implant-supported prosthetic restorations.

Longitudinal Study of Bone Height Change between Two Approaches for Sinus Floor Elevation.

Background and Objectives: The purpose of this study is to assess the long-term maintenance of each approach of sinus elevation, the crestal approach and lateral approach, by comparing the radiographic results of each technique. Materials and Methods: In total, 103 patients who had undergone an implant procedure with either the crestal approach or lateral approach method applied to their maxillary molar edentulous area were included. Using orthopantomographs, the radiographic changes were consistently evaluated over 3 years after the procedure (immediately after procedure and 1 year, 2 years and 3 years after implant placement) Results: The radiographic evaluation after 3 years of implantation with sinus elevation showed a significant amount of bone formation (8.07 mm for crestal approach and 12.00 mm for lateral approach method). The largest amount of grafted height loss occurred during the 1 year, but the resorption was minimal (0.98 mm for crestal approach and 0.95 mm for lateral approach method) over the entire 3 years. Conclusions: Although the lateral approach showed more bone growth, the amount of bone resorption was similar to that of the crestal approach. Both methods showed the highest amount of bone resorption in the first year, and the amount of change thereafter was insignificant. It is judged that both methods can be used according to the situation to help implant placement.