Buccal Bone Wall Research Articles

Assessment of buccal bone thickness of aesthetic maxillary region: a cone-beam computed tomography study.

PurposeThe aim of this study was to analyze the anatomical dimensions of the buccal bone walls of the aesthetic maxillary region for immediate implant placement, based upon cone-beam computed tomography (CBCT) scans in a sample of adult patients.MethodsTwo calibrated examiners analyzed a sample of 50 CBCT scans, performing morphometric analyses of both incisors and canines on the left and right sides. Subsequently, in the sagittal view, a line was traced through the major axis of the selected tooth. Then, a second line (E) was traced from the buccal to the palatal wall at the level of the observed bone ridges. The heights of the buccal and palatal bone ridges were determined at the major axis of the tooth. The buccal bone thickness was measured across five lines. The first was at the level of line E. The second was at the most apical point of the tooth, and the other three lines were equidistant between the apical and the cervical lines, and parallel to them. Statistical analysis was performed with a significance level of P≤0.05 for the bone thickness means and standard deviations per tooth and patient for the five lines at varying depths.ResultsThe means of the buccal wall thicknesses in the central incisors, lateral incisors and canines were 1.14±0.65 mm, 0.95±0.67 mm and 1.15±0.68 mm, respectively. Additionally, only on the left side were significant differences in some measurements of buccal bone thickness observed according to age and gender. However, age and gender did not show significant differences in heights between the palatal and buccal plates. In a few cases, the buccal wall had a greater height than the palatal wall.ConclusionsLess than 10% of sites showed more than a 2-mm thickness of the buccal bone wall, with the exception of the central incisor region, wherein 14.4% of cases were ≥2 mm.

Post-extraction evaluation of sockets with one plate loss--a microtomographic and histological study.

The aim of this study is to evaluate the characteristics of socket repair after teeth extraction with loss of a bone plate. Lower incisors were extracted from 120-day-old male rabbits. A standardized defect of 5mm in the buccal plate was created in one of the socket sites. Furthermore, complete closures of the sockets entrance were performed. Two groups of biopsies were obtained: one with 14days of healing and the other with 112, to perform the micro-CT and histological evaluations of the tested group with plate loss comparing with the control group with the intact buccal bone wall. Plate loss sites demonstrated reduction in width when compared to the intact ones and, this difference decreased with time. Long-term analysis showed that plate loss interfered in final ridge measurements by reducing the middle portion of the socket width compared to the intact plate sockets. The histological and micro-CT qualitative analysis showed that both sites presented similar pattern of healing, despite the reduced dimension found in plate loss sites.

Peri-implant bone response following immediate implants placed in the esthetic zone and with immediate provisionalization--a case series study.

The aim of this case series was to evaluate success and peri-implant bone response around Morse taper immediate implants with an immediate provisionalization. Twelve immediate implants were inserted in the maxilla of nine consecutively treated patients. Proximal bone response was evaluated with digital periapical radiographs, and the buccal wall height and width were evaluated with computed tomography. A slight decrease in the marginal bone crest (0.14 ± 0.41mm) at the mesial face and an increase (0.07 ± 1.58mm) at the distal face were observed. Considering the point where bone tissue meets the implant surface, there was a statistically significant increase at the mesial face (0.92 ± 1.29mm) and a not significant increase at the distal face (0.43 ± 1.63mm). Buccal bone wall width showed a statistically significant bone loss at the level of the implant/abutment junction (0.77 ± 0.75mm) and at 3mm (0.59 ± 0.76mm) and 6mm (0.46 ± 0.81mm) apically to the implant/abutment junction. The height of the buccal wall showed a not statistically significant resorption (0.20 ± 0.51mm). Based on the preliminary results (8months) of this case series study, it can be concluded that there was bone loss on the mesial bone crest level and on the buccal face and bone increases on the mesial and distal faces in the area where the bone meets the implant surface. Nevertheless, this is just a case series study, and long-term controlled clinical trials are essential for a definitive conclusion.

Predictors of Alveolar Process Remodeling Following Ridge Preservation in High-Risk Patients.

(1) To clinically evaluate horizontal remodeling of the alveolar process (hard and soft tissues) following ridge preservation in high-risk patients and (2) to identify predictors of such remodeling. Periodontally healthy nonsmoking patients with a failing tooth in the anterior maxilla (15-25) were selected for a prospective case series. All were in need of a single implant and demonstrated high risk for aesthetic complications given an incomplete buccal bone wall and/or thin-scalloped gingival biotype. Following flapless tooth extraction, ridge preservation was performed using one or more collagen-enriched, bovine-derived block grafts (Geistlich Bio-Oss® Collagen® 100 mg, Geistlich Pharma AG, Wolhusen, Switzerland) without the additional use of membranes or soft tissue grafts. The change in buccopalatal dimension of the alveolar process between baseline (prior to tooth extraction) and 4 months was assessed on the basis of superimposed occlusal slides. Regression analysis was performed to identify predictors of alveolar process remodeling. Forty-two patients (21 females, 21 males; mean age 38) met the selection criteria and consented to the treatment. Mean alveolar process remodeling was 14% (SD 7, range 4-30) with minimal remodeling (≤ 10%) in 16 patients (38%) and advanced remodeling (>20%) in 10 patients (24%). A single implant could be installed in all subjects without additional guided bone regeneration. Connective tissue grafting was performed later on in the treatment for aesthetic purposes, hereby compensating for tissue loss at the buccal aspect. Predictors of alveolar process remodeling were tooth location (central incisors and cuspids > laterals incisors and premolars), tooth abscess (p = .025), and buccal bone loss (p = .035). Alveolar process remodeling seems inevitable yet acceptable following ridge preservation in high-risk patients. Proper case selection may reduce the incidence of advanced remodeling.

Immediate implant placement, reconstruction of compromised sockets, and repair of gingival recession with a triple graft from the maxillary tuberosity: A variation of the immediate dentoalveolar restoration technique

Immediate implant placement into compromised sockets is challenging for clinicians. The 3-dimensional implant position, status of the buccal bone wall, and regeneration of the soft tissue contours all affect adequate esthetic and functional results. This clinical report presents a treatment protocol (a variation of the immediate dentoalveolar restoration concept) consisting of immediate implantation and the reconstruction of the buccal bone wall and gingival recession in a single procedure with a triple graft (cancellous and cortical bone and soft tissue graft).

The thickness of alveolar bone at the mandibular canine and premolar teeth in normal occlusion.

The purpose of this study was to investigate the alveolar bone thickness on the buccal and lingual aspects of mandibular canines and premolars using cone-beam computed tomography (CBCT). The differences between the left side and the right side and that in male and female measurements were reviewed. Three-dimensional CBCT of 20 subjects with normal occlusion (9 males and 11 females; mean [SD] age, 21.9 [3.0] y) were used. The thickness of the buccal and lingual bone walls, perpendicular to the long axis of the root, was evaluated at 3 and 5 mm apical to the cementoenamel junction (CEJ) and at the root apex. The mean buccal bone thickness measured at 3 and 5 mm apical to the CEJ was less than 2 mm on the canines and the premolars. The buccal bone thickness of the second premolar at 3 and 5 mm from the CEJ was significantly greater than that of the canine and the first premolar. There were no significant differences between the left and right sides, and the overall measurements of the alveolar bone thickness did not show significant male/female differences. This study presented the thickness of the buccal and lingual bone in different locations apical to the CEJ in subjects with normal occlusion and the frequency distribution of thick buccal bone wall (≥ 2 mm). The second premolar had the highest frequency distribution of thick buccal bone (≥ 2 mm) when compared with canine and the first premolar. The teeth with thin buccal bone (< 2 mm) should be treated with care for the implant because a thin buccal bone may be damaged more easily and buccal bone resorption may occur. This study may provide estimated value for patients with normal occlusion during tooth extraction and implant installation in the canine and premolar area of the mandible. Preoperative radiographic analysis, with care in using CBCT, may be applied for tooth extraction and implant therapy.

Periodontal responses to augmented corticotomy with collagen membrane application during orthodontic buccal tipping in dogs.

This prospective randomized split-mouth study was performed to examine the effects of absorbable collagen membrane (ACM) application in augmented corticotomy using deproteinized bovine bone mineral (DBBM), during orthodontic buccal tipping movement in the dog. After buccal circumscribing corticotomy and DBBM grafting into the decorticated area, flaps were repositioned and sutured on control sides. ACM was overlaid and secured with membrane tacks, on test sides only, and the flaps were repositioned and sutured. Closed coil springs were used to apply 200 g orthodontic force in the buccolingual direction on the second and third premolars, immediately after primary flap closure. The buccal tipping angles were 31.19 ± 14.60° and 28.12 ± 11.48° on the control and test sides, respectively. A mean of 79.5 ± 16.0% of the buccal bone wall was replaced by new bone on the control side, and on the test side 78.9 ± 19.5% was replaced. ACM application promoted an even bone surface. In conclusion, ACM application in augmented corticotomy using DBBM might stimulate periodontal tissue reestablishment, which is useful for rapid orthodontic treatment or guided bone regeneration. In particular, ACM could control the formation of mesenchymal matrix, facilitating an even bone surface.

Relationship Between the Buccal Bone Plate Thickness and the Healing of Postextraction Sockets With/Without Ridge Preservation

In 48 postextraction sites, sockets were grafted with bovine bone mineral plus collagen membrane (test) or had spontaneous healing (control). After 4 months, horizontal ridge width reduction was 0.71 mm in the test group and 4.04 mm in the control group, while vertical ridge loss was 0.58 mm and 1.67 mm, respectively. No correlation was found between the thickness of the buccal bone wall and the alveolar bone loss in the test group, while an inverse correlation was found in the control group. Ridge preservation compensated for postextraction alveolar ridge resorption irrespective of the buccal plate thickness, whereas leaving the extraction socket undisturbed may result in alveolar bone loss.

A prospective, randomized, controlled study using OsseoSpeed™ implants placed in maxillary fresh extraction socket: soft tissues response

The aim of this work was to study the peri-implant soft tissues response, by evaluating both the recession and the papilla indexes, of patients treated with implants with two different configurations. In addition, data were stratified by tooth category, smoking habit and thickness of buccal bone wall. The clinical trial was designed as a prospective, randomized-controlled multicenter study. Adults in need of one or more implants replacing teeth to be removed in the maxilla within the region 15-25 were recruited. Following tooth extraction, the site was randomly allocated to receive either a cylindrical or conical/cylindrical implant. The following parameters were studied: (i) Soft tissue recession (REC) measured by comparing the gingival zenith (GZ) score at baseline (permanent restoration) with that of the yearly follow-up visits over a period of 3 years (V1, V2 and V3). (ii) Interdental Papilla Index (PI): PI measurements were performed at baseline and compared with that of the follow-up visits. In addition, data were stratified by different variables: tooth category: anterior (incisors and canine) and posterior (first and second premolar); smoking habit: patient smoker (habitual or occasional smoker at inclusion) or non-smoker (non-smoker or ex-smoker at inclusion) and thickness of buccal bone wall (TB): TB ≤ 1 mm (thin buccal wall) or TB > 1 mm (thick buccal wall). A total of 93 patients were treated with 93 implants. At the surgical re-entry one implant was mobile and then removed; moreover, one patient was lost to follow-up. Ninety-one patients were restored with 91 implant-supported permanent single crowns. After the 3-year follow-up, a mean gain of 0.23 mm of GZ was measured; moreover, 79% and 72% of mesial and distal papillae were classified as >50%/ complete, respectively. From the stratification analysis, not significant differences were found between the mean GZ scores of implants with TB ≤ 1 mm (thin buccal wall) and TB > 1 mm (thick buccal wall), respectively (P < 0.05, Mann-Whitney U-test) at baseline, at V1, V2 and V3 follow-up visits. Also, the other variables did not seem to influence GZ changes over the follow-up period. Moreover, a re-growth of the interproximal mesial and distal papillae was the general trend observed independently from the variables studied. Immediate single implant treatment may be considered a predictable option regarding soft tissue stability over a period of 3 years of follow-up. An overall buccal soft tissue stability was observed during the GZ changes from the baseline to the 3 years of follow-up with a mean GZ reduction of 0.23 mm. A nearly full papillary re-growth can be detectable over a minimum period of 2 years of follow-up for both cylindrical and conical/cylindrical implants. Both the interproximal papilla filling and the midfacial mucosa stability were not influenced by variables such as type of fixture configuration, tooth category, smoke habit, and thickness of buccal bone wall of ≤ 1 mm (thin buccal wall).

Early healing of the alveolar process after tooth extraction: an experimental study in the beagle dog

To describe the early healing events in the alveolar socket during the first 8 weeks of spontaneous healing after tooth extraction. 16 adult beagle dogs were selected and five healing periods were analysed (4 h, 1 week, 2 weeks, 4 weeks, 8 weeks). Mandibular premolars were extracted and each socket corresponding to the mesial root was left to heal undisturbed. In each healing period, three animals were euthanatized, each providing four study sites. Healing was assessed by descriptive histology and by histometric analysis using as landmarks: the vertical distance between buccal and lingual crest (B'L') and the width of buccal and lingual walls at three different levels. Differences between means for each variable for each healing period were compared (ANOVA; p < 0.05). B'L' at baseline was 0.45 (0.18) mm and decreased during the healing period to a final value of 0.18 (0.08) mm. The lingual width (Lw) remains almost unchanged while the buccal width (Bw) at 1 (Bw1) and 2 (Bw2) mm was reduced in about 40% of its initial value. Minor vertical bone reduction in both the buccal and lingual socket walls were observed. A marked horizontal reduction of the buccal bone wall was observed mostly in its coronal aspect.

Buccal bone plate remodeling after immediate implants with or without synthetic bone grafting and flapless surgery: a histomorphometric and fluorescence study in dogs

The aim of this study was to evaluate the buccal bone plate remodeling after immediate implantation using the flapless approach with or without bone graft into the gap between the implant and the buccal bone. Eight dogs had the mandibular bicuspids extracted without flaps, and four implants were installed on each side, totaling eight implants per animal. Randomly, in one side, the implants were positioned at the bone crest level (equicrestal), and on the opposite side, the implants were positioned 2 mm subcrestal. All the implants were positioned 2.0 mm from the buccal bone plate (gap) and associated or not with grafting material. Therefore, the following treatments were performed: implants subcrestal test (SCTG) with bone graft and control (SCCG) without bone graft, and equicrestal test (ECTG) with bone graft and control (ECCG) without bone graft. One week following the surgeries, metallic prostheses were installed. Bone markers were administered 1, 2, 4, and 12 weeks after implant placement for fluorescence analysis. Ground sections were prepared from 12-week healing biopsies, and histomorphometry was performed. The histomorphometric evaluation presents significant better results for the ECTG in the vertical crestal bone resorption, but the other parameters showed better results for the SCCG. The fluorescence evaluation in adjacent areas showed numerically different results between groups with a small decrease at 12 weeks, except for the SCCG, which was higher at this time. The distant area showed a continuous increase in the marked bone. The equicrestally placed implants presented little or no loss of the buccal bone wall. The subcrestally positioned implants presented loss of buccal bone, regardless of the use of bone graft. However, the buccal bone was always coronal to the implant shoulder. Both the equicrestal and subcrestal groups were benefited in the early stages of bone healing as evidenced by the fluorescence analysis.

Buccal bone plate in immediately placed and restored implant with Bio‐Oss® collagen graft: a 1‐year follow‐up study

The aim of this study was to radiographically assess the vertical and horizontal alterations of buccal alveolar bone after the insertion of a post-extractive implant using Bio-Oss(®) Collagen graft. The study was designed as a prospective study. Adult patients were eligible for the study if they needed one or more immediately inserted and immediately restored implant replacing teeth to be extracted within region 15-25. After the insertion, the buccal gap was carefully grafted using Bio-Oss(®) Collagen and the implant immediately restored. Cone-Beam Computed Tomography (CBCT) was performed immediately after surgery and a series of measurements were made to determine the dimension of the buccal bone plate and the void between implant and extraction socket. A second CBCT was taken and the measurements repeated after 12 months. Altogether, 69 patients were included in the study; a total of 69 implants were inserted. The study demonstrated that the extraction of a tooth and the immediate insertion of an implant together with an xenograft resulted in alterations of the vertical and horizontal dimension of the buccal bone plate (respectively, 25.6% and 29.3%). Nevertheless, the vertical and horizontal gap reduction was nearly complete (respectively, 99.3% and 99.1%) and the implant was normally in contact with buccal bone. Implant placement into extraction sockets can result in favorable radiological results even in the presence of evident alterations of the buccal bone wall.

A systematic review on the frequency of advanced recession following single immediate implant treatment

It has been stated that midfacial recession is common following immediate implant treatment (IIT). The objective of this systematic review was to assess the frequency of advanced recession (>1 mm) following single IIT. An electronic search in Pubmed, Web of Science and the Cochrane Oral Health Group Specialized Trials Register database was performed using a search algorithm. Reference lists of relevant articles were also scrutinized to identify prospective studies on ≥10 implants installed in patients with an intact buccal bone wall and followed for ≥12 months. Study eligibility and quality were independently assessed by two investigators. Primary outcome variables were advanced inter-proximal and midfacial recession defined as soft tissue loss surpassing 1 mm between the pre- or postoperative status and the final re-assessment. Thirteen of 171 papers were selected. Inter-examiner agreement on eligibility (κ = 0.879; p < 0.001) and quality (κ = 0.788; p < 0.001) was high. Advanced inter-proximal recession was described in 0-27% of the cases. However, these data were only based on two studies. Mean inter-proximal recession was frequently reported (11/13) and was <1 mm in all studies suggesting limited risk for advanced inter-proximal recession. Advanced midfacial recession was described in 0-64% of the cases. Again, few papers provided such information (4/13). Only one of these studies demonstrated high risk for advanced midfacial recession (>10%). This could be attributed to the fact that implants had not been restored with an immediate implant crown, which seems of pivotal importance given the results of a randomized controlled trial reporting on the preserving effect of immediate provisionalization on midfacial mucosa level. There is limited evidence to support an increased risk for midfacial recession following flap surgery and in patients with a thin-scalloped gingival biotype. The impact of implant-specific parameters on inter-proximal and midfacial soft tissue level seems conflicting. Soft tissue recession may be expected following IIT and multiple factors seem to contribute to the phenomenon. Taking into account the paucity of papers, patients with an intact buccal bone wall and thick gingival biotype, treated by means of flapless surgery and an immediate implant crown may demonstrate limited risk for advanced midfacial recession (<10%). Proper risk assessment addressing diagnostic, surgical and restorative aspects is mandatory to avoid compromised outcome of IIT.

Comparison Between Graft and No-Graft in an Immediate Placed and Immediate Nonfunctional Loaded Implant

This study compares success rates and hard and periimplant soft tissue responses, between placement and nonplacement of the following five different types of grafts: autogenous bone (A); deproteinized bovine bone mineral (H); demineralized freeze-dried bone allograft (D); A + H; A + D in horizontal gaps between implant surfaces and the buccal bone wall, in immediate placed and immediate nonfunctional loaded implants in maxillary arch. Forty-one patients with a mean age of 42.5 years were enrolled in this retrospective comparative study. Outcome assessments included clinical and radiographic evaluation. Patients were followed up on average for 32 months with a 100% implant survival rate. No significant difference was found between the two groups. Results of this study suggest that immediate placed and immediate restored single implants are valuable therapeutic options in the maxillary arch. The types of grafts placement: A, H, D, A + H, and A + D in horizontal gaps have no additional benefit in promoting better clinical outcomes given that a thick gingival biotype is present.

Soft Tissue Preservation and Pink Aesthetics around Single Immediate Implant Restorations: A 1‐Year Prospective Study

(1) To document soft tissue aspects using a specific protocol for immediate implant treatment (IIT) following single-tooth removal; (2) to evaluate whether this protocol allows preservation of pink aesthetics as objectively assessed. Patients with a thick gingival biotype and intact buccal bone wall upon extraction of a single tooth in the aesthetic zone (15-25) were consecutively treated. The protocol included flapless extraction and implant surgery, socket grafting, immediate nonocclusal loading with a screw-retained provisional crown, and replacement by a permanent crown 6 months thereafter. The outcome was assessed after 3, 6, and 12 months. Cases demonstrating major alveolar process remodeling and/or advanced midfacial recession (>1 mm) at 3 months were additionally treated with a connective tissue graft (CTG). The emergence profile of the provisional crown was replicated for all permanent crowns. Twenty-two patients (12 men, 10 women; mean age 50) were treated after tooth extraction for nonperiodontal reasons using a novel bone condensing implant with variable-thread design, conical connection, and platform switch (NobelActive®, Nobel Biocare, Göteborg, Sweden). One implant failed and mean marginal bone loss was 0.1 mm (p = .059). Temporary mesial papilla reduction occurred, whereas distal papilla reduction was permanent (mean 0.5 mm; p = .001). At 3 months, five cases demonstrated major alveolar process remodeling and two advanced midfacial recession. Hence, slight initial decline in the pink esthetic score (PES) (p = .053) was observed. CTG resulted in a steady improvement of the PES after 3 months (p ≤ .037). At 12 months, pink aesthetics (mean PES 12.15) was comparable to the preoperative status (mean PES 11.86; p = .293). Distal papillae had significantly deteriorated (p = .020) in this time span, whereas midfacial contour had significantly improved (p = .005). Preservation of pink aesthetics is possible following IIT. However, to achieve that, CTG may be necessary in about one-third of the patients. Major alveolar process remodeling is the main reason for additional treatment.

Dimensional Ridge Preservation with a Novel Highly Porous TiO2Scaffold: An Experimental Study in Minipigs

Despite being considered noncritical size defects, extraction sockets often require the use of bone grafts or bone graft substitutes in order to facilitate a stable implant site with an aesthetically pleasing mucosal architecture and prosthetic reconstruction. In the present study, the effect of novel TiO2 scaffolds on dimensional ridge preservation was evaluated following their placement into surgically modified extraction sockets in the premolar region of minipig mandibles. After six weeks of healing, the scaffolds were wellintegrated in the alveolar bone, and the convex shape of the alveolar crest was preserved. The scaffolds were found to partially preserve the dimensions of the native buccal and lingual bone walls adjacent to the defect site. A tendency towards more pronounced vertical ridge resorption, particularly in the buccal bone wall of the nongrafted alveoli, indicates that the TiO2 scaffold may be used for suppressing the loss of bone that normally follows tooth extraction.

Clinical evaluation of a ridge augmentation procedure for the severely resorbed alveolar socket: multicenter randomized controlled trial, preliminary results

To radiographically analyze extraction sites left untreated or treated using a socket preservation technique. A total of 20 patients scheduled for single extraction in the maxilla from second to second premolar were enrolled in this study. All sites showed a bone defect >5 mm at the buccal wall and no soft tissue recession. At baseline (T0), tooth extraction was performed; subsequently, sites were randomly allocated to the control (CG: left to heal without grafting) or test group (TG: grafted using hydroxyapatite). Two months later (T1), implants were inserted and eventual GBR procedure was performed. Three months later, the definitive crown was placed. Follow up was 24 months (T2). A cone-beam computed tomographic examination (CT) was performed at each time point. At each radiographic analysis, horizontal and vertical widths of the sockets were measured. Comparisons between CG and TG were performed by a Wilcoxon non-parametric test. At the end of the study, no patient dropped out and all implants inserted (10 in each group) resulted integrated. GBR procedures were performed at T1 only in the CG. In the CG, the mean value of the horizontal width in the coronal CT slices was 0.98 mm (± 0.37), 7.70 mm (± 0.92), 7.45 mm (± 0.69) at T0, T1 (after bone regeneration) and T2, respectively. In the TG, the mean value of the horizontal width in the coronal CT slices was 0.96 mm (± 0.41), 8.97 mm (± 1.91), 9.48 mm (± 1.56); at T2, it was 9.52 mm (± 1.87) at T0 (pre- and post-socket preservation) T1 and T2, respectively. At each follow up, the mean horizontal bone width in TG was statistically significantly greater than in the control group (P < 0.05). At T0, mean value of the vertical bone defect length (BDL) was 6.93 mm for TG, 6.5 mm for CG. At T1 and T2, mean BDL value was 0 for both groups. Statistically significant difference was not found between TC and CG at any time point (P > 0.05). This randomized controlled trial suggested that in sites with buccal bone defects >5 mm, the application of HA can minimize alveolar crest resorption following tooth extraction. Furthermore, compared with traditional regenerative procedure carried out following socket healing, this preservation technique seems to result in better horizontal regeneration of the buccal bone wall.

Comparison of Periapical Radiography and Limited Cone-Beam Computed Tomography in Mandibular Molars for Analysis of Anatomical Landmarks before Apical Surgery

Introduction The purpose of the present study was to evaluate the detectability and dimensions of periapical lesions, the relationship of the mandibular canal to the roots of the respective teeth, and the dimension of the buccal bone by using limited cone-beam computed tomography (CBCT) in comparison to conventional periapical (PA) radiographs for evaluation of mandibular molars before apical surgery. Methods The study comprised 38 molars with 75 roots. The type of PA lesion as diagnosed on PA radiographs was compared with the type of lesion seen on sagittal and coronal CBCT sections. The distances of the apices of the first mandibular molars and basal border of the PA lesion to the coronal lining of the mandibular canal were assessed with PA radiographs and corresponding sagittal and coronal CBCT images. Furthermore, coronal CBCT images were used to measure the distance from the apices to the buccal bone surface and the corresponding width of the cortical bone plate. Results Of 58 detected PA lesions, 15 (25.9%) lesions diagnosed with sagittal CBCT slices were missed with PA radiography. The distance between the apices and the upper border of the mandibular canal was only measurable in 24 of 68 radiographs (35.3%) by using PA images. The cortical bone wall had a mean thickness of 1.7 mm, whereas the total buccal bone wall (cortical and spongious) measured 5.3 mm on average. Conclusions The present study highlights the advantages of using limited CBCT for treatment planning in mandibular molars before apical surgery.

Implant Restoration 3 Months after One Stage Sinus Lift Surgery in Severely Resorbed Maxillae: 2‐Year Results of a Multicenter Prospective Clinical Study

This multicenter prospective study was aimed to clinically evaluate implant behavior inserted in severely resorbed maxillae and restored 3 months after sinus grafting. In three clinical centers, 67 totally rough wide diameter implants were inserted during 30 consecutive sinus lifts. Computed tomography and panoramic analysis were preoperatively requested for each patient. Sinus grafting was performed using a nano-crystalline hydroxyapatite sole bone filler; no membrane was used to cover the buccal window. Preoperative residual bone height ranged between 1-4 mm (mean value: 2.70 mm, standard deviation [SD]: 0.9 mm). Uncovering procedure was carried out following 3 months of healing; 2 weeks later, a definitive restoration was seated using platform switching concept. To monitor stability changes, resonance frequency analysis was performed and implant stability quotient (ISQ) values were collected at the first surgery (baseline, T(0) ), at the abutment connection (T(1) ), and at 2-year follow-up (T(2) ). To measure bone changes, patients underwent panoramic analysis after 2-year follow-up. The image analysis software calculated the grafted bone height changes at level of implant site comparing preoperative and follow-up panoramic films; the software compensated for eventual radiographic distortion. Mean ISQ value was 35.7 (SD: 8.8) at baseline, 66.61 (SD: 4.76) at T(1) , and 77.9 (SD: 4.7) at T(2) . Statistically significant differences (p ≤ 0.005) regarding ISQ mean values were found between T(1) and T(0) , as well as between T(1) and T(2) . After 24 months of functional loading, only two implants were lost (cumulative survival rate: 97%). During the same observation period, the mean value of radiographic vertical height of grafted sinus was 13.75 mm (SD = 1.3 mm), with a mean gain of 11 mm. Within the limits of this study, despite preoperative residual bone height ranging 1 to 4 mm and absence of the membrane covering the buccal bone wall, maxillary sinus lift restoration 14 weeks after first surgery seems to be a reliable procedure using totally-rough surfaced implants restored using platform switching concept and nano-structured hydroxyapatite as sole bone filler.

Morphology of the nasopalatine canal and dental implant surgery: a radiographic analysis of 100 consecutive patients using limited cone-beam computed tomography

To analyze the dimensions and anatomic characteristics of the nasopalatine canal and the corresponding buccal bone plate of the alveolar process, using limited cone-beam computed tomography (CBCT) imaging. Partially edentulous patients scheduled for CBCT imaging for further radiographic evaluation of a prospective implant recipient site in the anterior maxilla were consecutively enrolled in this study. For all CBCT images, a limited field of view (FOV) of 4 × 4 cm, 6 × 6 cm or 8 × 8 cm was selected. Reformatted sagittal and coronal slices were analyzed with regard to dimensions and anatomic characteristics of the nasopalatine canal as well as the dimensions of the buccal bone wall. Factors influencing these parameters were evaluated using univariate and multivariate linear regression models. The study population comprised 44 men and 56 women with a mean age of 43.09 years. Gender of the included patients had a statistically significant influence on the dimensions of the buccal bone plate, the mean values being generally higher for male subjects. In the multivariate linear regression model, the status of the central maxillary incisors (both present, one missing, and both missing) and the time elapsed since loss of the central incisors (<1 year vs. >1 year) were independently associated with buccal bone wall measurements, adjusted for age and sex. The present study demonstrates decreasing values for the coronal width of the buccal bone wall in patients with missing central incisors and a time span since tooth loss of over 1 year. The age of the patients had a significant influence only on the length of the nasopalatine canal, with the mean values generally decreasing with an increasing age. The limited CBCT scans with FOVs varying between 4 × 4 and 8 × 8 cm are a valid diagnostic alternative to cross-sectional imaging in the anterior maxilla for dental implant treatment planning.