Crestal Bone Level Research Articles

Bone formation in large/moderate gap after immediate implantation in response to different treatments: a pre-clinical study in the canine posterior mandible.

This study aims to investigate different treatments on new bone formation around immediate implants in the canine posterior mandible with varying sized mesial-distal gap. The 4th premolar and the 1st molar of six Labrador dogs were extracted from the mandible, and 4 dental implants were placed 1mm below the level of the buccal bone crest. Moderate/large mesial-distal gaps between the implants and the sockets were treated with one of four methods and divided into the following groups: (1) the blank group, (2) the collagen membrane (CM) group, (3) the deproteinized bovine bone mineral (DBBM) group, and (4) the DBBM + CM group. Sequential fluorescent labeling was performed at 4, 8, and 10 weeks after the operation. After 12 weeks, the dogs were euthanized, and specimens were collected for micro-CT scanning and histological analysis. The survival rate of immediate implant was 100%. Micro-CT showed significant differences in bone mineral density (BMD) and bone volume fraction (BVF) among groups (P = 0.040, P = 0.009); other indicators were not significantly different among groups. Histological analysis showed the proportion of new bone formation and bone-to-implant contact were not significantly different among groups. No significant difference in bone reduction height around dental implant among four groups and varied mesial-distal gap size. Owing to the restricted sample size, this pilot study lacks conclusive findings. Within the limitation, this study demonstrated that although DBBM significantly increase BMD and BVF, the use of DBBM/CM didn't significantly improve bone formation and healing in extraction sockets around the implants in both moderate and large mesial-distal gap. The use of deproteinized bovine bone in conjunction with collagen is a common practice in immediate implantation procedures in the posterior mandible. However, there is a lack of conclusive evidence regarding the timing and circumstances under which they should be employed.

Prefabricated shouldered abutments enable successful restoration of molar crowns on implants.

This retrospective study evaluated the effect of selected clinical and patient factors on survival, success, and peri-implant bone level changes of locking taper implants supporting molar crowns on Bicon's prefabricated shouldered abutments. A total of 234 patients, who received 274 single molar crowns supported by locking taper implants were included in this retrospective study. Kaplan-Meier survival analysis was used to assess overall implant survival, prostheses survival, and success. Crowns were either monolithic (resin based) or bilayered (milled fiber-reinforced composite coping veneered with indirect composite). Early and late changes in marginal bone levels were plotted and analyzed with equivalence testing to compare the effects of different factors on crestal bone levels. At 9.5 years after implant surgery, the implant survival probability was 94.2%, the probability of prosthesis survival was 91.4%, and the probability of prosthetic success was 90.4%. Neither the use of different crown materials, nor the choice of monolithic versus bilayered crown construction, significantly affected the probability of prosthetic success. Marginal bone levels, on average, trended downwards towards the top of the implant within the first 2 years after functional loading, and remained stable on average, since then. Factors affecting bone levels included the use of nonsteroidal anti-inflammatory drugs, which precluded early implant bone loss; and subcrestal implant placement, which was linked to significantly higher long-term bone levels. The implant and abutment system studied resulted in high implant and prosthetic survival rates, regardless of prosthetic material used, with stable bone levels over time.

Digital assessment of supracrestal tissue attachment and its correlation with dentogingival components.

The aim of this study is to measure, in vivo, the supracrestal tissue attachment dimensions (STADs) by means of a noninvasive digital method and to investigate the association between STADs and gingival thickness (GT), tooth position, tooth length, tooth width, keratinized tissue width (KTW), buccal bone thickness (BBT), and bone crest (BC) level. Nineteen periodontally healthy subjects who previously received full mouth periodontal charting, cone beam computed tomography, and intraoral scan for the purpose of implant planning were included in the study. A digital imaging software was used for the superimposition of Digital Imaging and Communications in Medicine and stereolithography files, along with hard and soft tissue measurements. Pearson's correlation and ANOVA statistical analyses were used to investigate potential trends between STADs and other dentogingival components. A total of 203 teeth were assessed, with an average STADs of 2.05mm (±0.99mm). STADs were larger in mandibular than maxillary teeth (p-value <0.001) and decreased from anterior to posterior teeth. STADs exhibited an inverse relationship with BBTs and GTs (p-value <0.001) and the KTW (p-value=0.05). Positive correlations were found between GT and BBT (p-value <0.001), whereas both were negatively correlated with the distance between the cementoenamel junction and BC (p-values 0.019 and 0.006, respectively) and positively correlated with KTW (p-value <0.001). This study highlighted the dynamic nature of STA relative to tooth position. Additionally, it explored the intricate relationships of STADs with various dentogingival components. To the best of the authors' knowledge, this study represents the first application of CBCTs, intraoral scans, and clinical probe depths for noninvasive supracrestal tissue attachment measurements. This study advocates for a personalized assessment of supracrestal attachments, incorporating tooth position and other dentogingival components. The study emphasizes the importance for practitioners to consider the specific patient gingival phenotypes during restorative or surgical planning to avoid adverse outcomes.

The Impact of Implant Abutment Angle and Height on Peri-implant Tissue Health: Retrospective Analyses from a Randomized Controlled Clinical Trial.

To examine the influence of abutment emergence angle and abutment height on marginal peri-implant bone stability in patients not considered susceptible to peri-implantitis. Furthermore, it was analyzed whether titanium-base (Ti-base) abutments lead to wider abutment emergence angles compared to one-piece abutments. A total of 48 abutments (ie, 24 Ti-base and 24 one-piece abutments in 24 patients) were evaluated at abutment installation, after 1 year, and thereafter on a yearly basis for up to 5 years. Clinical and radiographic outcome variables were assessed. With regard to peri-implant marginal bone stability, only moderately negative, albeit significant, correlations were found on the mesial sides of the one-piece abutments after 4 and 5 years for an abutment emergence angle > 30 degrees. No statistically significant negative correlations were found for distances of ≤ 1.5 mm between the restoration margin and the crestal peri-implant bone level for either Ti-base or for one-piece abutments. Furthermore, abutments bonded to Ti-bases were not associated with larger emergence angles than one-piece abutments. For patients at low risk of developing peri-implantitis, it can be concluded that neither a larger abutment emergence angle (> 30 degrees) nor a distance of ≤ 1.5 mm between the restoration margin and the crestal peri-implant bone level are associated with marginal peri-implant bone loss. Furthermore, abutments bonded to Ti-bases are not associated with wider emergence angles than one-piece abutments.

Evaluation of Crestal Bone Levels using Simvastatin as an Adjuvant Around Immediate Implants - A Clinico Radiographic Study.

Simvastatin was used as an adjuvant medication in this clinico-radiographic investigation to assess the impact on crestal bone levels around immediate implantation. A randomized controlled trial with 50 patients who needed an implant placed right away was done. Simvastatin was used as an adjuvant in groups ((Group A), whereas group (Group B)) served as the control group for the participants. At baseline and during follow-up visits, clinical measures such as probing depth (PD) and bleeding on probing (BOP) were measured. At baseline and 12 weeks, radiographic measurements of crestal bone levels were taken. At 12 weeks, Group A demonstrated a significantly lower PD and BOP than did Group B. Furthermore, at 12 weeks, Group A showed greater crestal bone preservation than did Group B. The results of the statistical analysis showed that the two groups were significantly different. The results of this study indicate that simvastatin use as an adjuvant medication after immediate implant insertion contributes to better clinical outcomes and greater crestal bone preservation. Simvastatin may be helpful in increasing bone regeneration, decreasing inflammation, and soft tissue healing. These findings demonstrate how simvastatin may be used as an additional therapy to enhance the effectiveness of rapid implant implantation operations.

The Impact of Different Implant Approaches in Overdenture Rehabilitated Diabetic Patients: A Two-Year Follow-Up

Diabetes Mellitus (DM) is identified as an important condition that leads to implant complications, and the apico-coronal position and the prosthetic abutment seem to interfere with peri-implant tissue behavior This study aimed at assessing the effect on peri-implant parameters after implant loading of two different methodologies in type two diabetics patients (T2DM) who received implant muco-retained overdentures. Twenty-two mandibular edentulous T2DM received two implants: Test group: prosthetic abutment of a diameter smaller than the platform of the implant and a morse taper subcrestal implant level; Control group: prosthetic abutment of diameter identical to the platform and hexagonal external implant placed at crestal bone level. Clinical, inflammatory, and tomographic evaluations were performed at baseline (after prosthesis installation), and twelve and twenty-four months after implant loading. Test implants presented inferior probing depth and clinical attachment level compared to control at baseline and 12 months (p &lt; 0.05). Test implants presented reduced levels of pro-inflammatory cytokines at 24 months compared to the control implants (p &lt; 0.05). The control group had more changes in bone parameters from baseline to the first and second years (p &lt; 0.05). The test group resulted in reduced bone remodeling and better clinical conditions and positively modulated peri-implant immunoinflammatory molecules. Trial identification UTN code: U1111-1239-3638.

Comparison of crestal bone loss and papilla fill after conventional and immediate implant placement: A 12 month clinical and radiographic prospective study

Background The problem of missing teeth persists in all age groups. The main objective of implants in dentistry is to provide a restoration that reconstructs the shape and restores esthetics and functions of edentulous areas. The objectives of this study are to compare the crestal bone level changes and papillary fill after placement of implants in fresh extraction socket, i.e. immediate implant placement, and healed extraction socket, i.e. delayed or conventional implant placement, and to assess other clinical parameters such as modified plaque index (mPI), modified gingival index (mGI) and gingival biotype in between the groups and within the groups. Methods 18 patients were recruited in the study out of which 9 patients received implants as per immediate implant placement protocol (group 1) and 9 patients received implants as per conventional implant placement protocol (group 2). All patients were evaluated for gingival biotype, mPI and mGI and papillary fill was assessed as per Jemt’s papilla score as clinical parameters. Implant site was assessed for radiographic bone loss using Image J software. Statistical analysis was performed using independent t test, paired t test and chi square test. Results At the end of 1 year, results showed that crestal bone loss was seen more in the immediate group than the conventional group. Conventional implants showed better papillary fill than implants placed in fresh extraction sockets. Plaque scores were assessed as per modified plaque index, which showed better results in the conventional group. Modified gingival index was used to assess gingival status which showed better results in the immediate group one year later. Conclusions Findings from the study suggest that crestal bone loss was found to be increased in the immediate group than the conventional group and papillary fill was better in the conventional group than the immediate group. Registration: CTRI (CTRI/2019/09/021340).

Analysis of ultra-short implants with different angulations: a retrospective case-control study with 2 to 9years of follow-up.

Does the angulation of ultrashort implants influence the stability of the peri-implant bone? The present study aimed to evaluate the effectiveness of non-axial ultrashort implants after 2 to 9years of follow-up in resorbed alveolar ridges. All partially edentulous patients with ultrashort implants (< 6mm) used in the posterior region of an atrophic mandible or maxilla, to support partial dentures in conjunction with standard implants, were included in this study. Peri-implant bone loss, success and survival rates, crestal bone levels, crown-to-implant ratio and implant angulation were measured for each implant. Implants were divided into two groups: straight implants with angulation < 17° (control group) and tilted implants with angulation > 17° (test group). Statistical analysis was used to find any significant differences between the two study groups and to investigate significant linear correlations among all the variables (p = 0.05). A total of 42 ultrashort implants with a mean of 4years of follow-up were included: 20 ultrashort axially loaded implants and 22 tilted implants. Mean crestal bone levels from baseline loading to maximum follow-up did not reveal statistical differences in regard to PBL; mean success and survival rates were 100% in all groups. PBL, success and survival rates of axial ultrashort implants and tilted ultrashort implants are comparable to those of conventional implants. This retrospective study revealed that ultrashort implants, even when placed with an angulation > 17°, can safely be used to support partial fixed prostheses. Further prospective clinical studies with larger samples and prospective design are needed to confirm these findings.

Implant-supported single all-ceramic crowns made from prefabricated (stock) or individualized CAD/CAM zirconia abutments: A 5 year randomized clinical trial.

The aim of this randomized, prospective, and clinical multicenter study was to compare the overall clinical performance of two restorative options over a 5-year period: individualized CAD/CAM abutments veneered with a hand-layered ceramic, and prefabricated zirconium dioxide abutments veneered with press ceramic and inserted into a single edentulous gap in the anterior maxilla. Forty subjects were recruited from two universities: 20 from the University of XX and 20 from the University of XY. Each subject received an implant to restore a single edentulous gap in the maxillary anterior region (14-24 FDI). 20 patients were randomized into each Group. Group A received a one-piece single crown produced from a prefabricated zirconia abutment with pressed ceramic and Group B received an individualized CAD/CAM zirconia abutment with a hand-layered technique. After 5 years, the aesthetic and radiographic parameters were assessed. Group A had four dropouts and one failure, resulting in a 95% survival rate and 95% success rate. Group B had two dropouts and two failures which resulted in a 90% survival rate and 90% success rate. No crestal bone level changes were observed, with a mean DIB of 0.06 mm in Group A and 0.09 mm in Group B. No statistically significant differences were present at baseline, 6 months, 1 year, 3 years, or 5 years for DIB values between time points and groups. Pink aesthetic score/white aesthetic score, Peri-Implant and Crown Index, and Implant Crown Aesthetic Index values were stable over time at all five points for both groups. Both implant-supported restorative options represent a valuable treatment option for the restoration of implant crowns in the anterior maxilla. In general, the use of ceramic abutments in the anterior zone represents a valuable treatment procedure with both standardized and CAD/CAM individualized abutments and following the recommendations from the respective manufacturer(s).

Validation of novel measurement protocols proposed for the standardized assessment of crestal bone levels: A cone-beam computed tomography study

Validation of novel measurement protocols proposed for the standardized assessment of crestal bone levels: A cone-beam computed tomography study

Comparison of the effect of zirconia and titanium abutments on peri-implant hard and soft tissues.

The primary objective of this research was to assess and compare the impact of customized zirconia (Zr) and titanium (Ti) abutments, placed on early loaded dental implants, on both hard tissue (as measured crestal bone level) and soft tissue (as assessed by sulcular bleeding index [SBI], probing depth [PD], and Pink Esthetic Score [PES]), through clinical and radiographic evaluation. This research involved a sample of 15 patients who had partially dentulous mandibular arch. Within this group, a total of 30 implants were surgically placed. Specifically, each patient received two implants in the posterior region of the mandible, and the bone density in this area was classified as D2 type. In each patient, one implant was loaded with Zr abutment and the other was loaded with Ti abutment. The bone quality in the area of implant placement was Type D2. Two groups were created for this research. Each group consisted of 15 early loaded dental implants with customized Zr abutments and customized Ti abutments respectively. Hard- and soft-tissue changes were evaluated in both the groups. Evaluation of crestal bone loss (CBL) with cone beam computed tomography and SBI, PD and PESs were evaluated by various indices at 2, 4, and 6 months postloading. After obtaining the readings, data were subjected to statistical analysis and comparison of quantitative data was done, paired t-test was used. The mean CBL in the Ti abutment is higher; the difference between the two groups was not statistically significant. SBI and PD for Zr were higher, but there was no statistically significant difference between the two groups. Zr had a higher PES than Ti abutment and the difference between the two groups was statistically significant. In the literature till date, the PES of Zr abutments were proven better for provisional restorations in implant prosthesis, but very few literatures support the same for the final implant restorations. The study did not reveal a clear advantage of either Ti or Zr abutments over the other. Nevertheless, Zr abutments tended to produce a more favorable color response in the peri-implant mucosa and led to superior esthetic outcomes as measured by the PES.

Therapeutic effectiveness of keratinized mucosa augmentation for functioning dental implants: A systematic review and meta-analysis.

This study aimed to provide the latest updates on the therapeutic effectiveness of keratinized mucosa (KM) augmentation using autogenous soft tissue grafts for dental implants retaining prostheses. A systematic search of electronic databases was conducted on autogenous soft tissue grafts to create and/or augment KM for functioning dental implants. Two investigators independently extracted data from the selected 11 clinical studies, including 290 participants, from the initially retrieved 573 publications. A lack of KM surrounding dental implants was associated with greater mucosal inflammation. A free gingival graft (FGG) was used to increase the KM width, and a connective tissue graft (CTG) was used to manage peri-implant mucosal recession (MR). The weighted mean gain in KM was 2.6 mm from the selected FGG studies, with a significant reduction in mucosal inflammation and no changes in crestal bone levels for up to 4 years. The weighted mean reduction in MR was 2 mm in selected CTG studies. A lack of KM negatively affects soft tissue health around dental implants. FGG was effective in increasing KM and reducing mucosal inflammation, whereas CTG was effective in decreasing MR.

Retraction Note: Narrow- versus mini-implants at crestal and subcrestal bone levels. Experimental study in beagle dogs at three months.

Retraction Note: Narrow- versus mini-implants at crestal and subcrestal bone levels. Experimental study in beagle dogs at three months.

Clinical and CBCT Assessment of Role of Bisphosphonate on Osteotomy Site and Implant Surface.

To assess the role of bisphosphonate on osteotomy site and implant surface. Twenty patients with adequate width and height of edentulous space and a single missing posterior tooth between the ages of 25 and 55 were incorporated in this research. Ten participants received implant therapy alone; the other ten patients received implant therapy and bisphosphonate application to osteotomy site and the implant surface. Changes in the crestal bone level were seen in both the study and control groups. At 1 year, crestal bone loss was less in the bisphosphonate-treated group than in the control group. The quantity of crestal bone loss was reduced when bisphosphonate (sodium alendronate) was applied locally near the implant and osteotomy site.

A novel periodontal endoscopy-aided non-incisional periodontal regeneration technique in the treatment of intrabony defects: a retrospective cohort study

BackgroundGingival recession and post-operation discomfort are still a problem for patients receiving the periodontal regeneration surgery for intra-bony defects. To further reduce the trauma and the post-operation gingival recession, a novel periodontal endoscopy-aided non-incisional regeneration technique (NIT) was proposed in the treatment of intra-bony defects.MethodsRetrospective analysis of 21 subjects treated with NIT and 21 subjects with periodontal endoscopy-aided scaling and root planing (PSRP) at baseline and 1-year evaluation was conducted. After removing the subgingival calculus and granulation tissue, bone grafting materials were placed into intrabony defects with the assistance of a gingival retractor in the NIT group. Probing depth (PD), gingival recession (GR), clinical attachment level (CAL), as well as the distance between bone crest (BC) level and base of the defect (BD) (intrabony defect depth, IBD) were evaluated at baseline and 1 year after treatment.ResultsAt 1-year follow-up, the value of CAL, PD and IBD were statistically significant different compared with baseline in both two groups (p<0.001). CAL gain (p = 0.012) and PD reduction (p = 0.004) was greater in the NIT than PSRP. However, no difference in the IBD reduction was found between the NIT group and PSRP. Better CAL gain and PD reduction was achieved in the 1-year term in the NIT when compared with PSRP.ConclusionNIT have resulted in significant gains in both clinical and radiographic parameters. NIT might be utilized as an alternative of the surgical treatment for periodontal intrabony defects.Trial registrationThis clinical trial registration was registered retrospectively (August 3, 2023) and the number is ChiCTR2300074317.

Impact of Chitosan-Coated Implants on the Alveolar Ridge: Preliminary MicroCT and Radiographic Study in a Canine Model.

To compare crestal bone loss (CBL) 12 weeks after immediate implant placement in the mandible of a canine model between titanium (Ti) implants with a conventional etched surface (SLA type) and Ti implants coated with chitosan (Cht). A total of 48 Ti-Al16-V4 implants (24 experimental and 24 control) with an internally connected tapered screw design were randomly placed into six canine maxillae, 4 per hemiarch. The experimental implants were coated with Cht by immersion and sterilized with ethylene oxide. Primary stability was measured using the Osstell device, and no grafting materials were used. The 3D microCT measurements included crestal bone volume (CBV) and bone volume change in crestal area (ΔCBV), which were considered outcome measures. Parallelized periapical radiographs were also taken at the time of implant placement and after 12 weeks to assess changes in crestal bone levels. In terms of volumetric changes, it was observed that the experimental group showed better results than the control group (P = .049 and P = .303, respectively). Regarding the implant sites, no significant differences were found between the experimental implant sites and control sites. The implants placed at P4 level in the experimental group obtained the best result (P = .041). The linear data obtained from the periapical radiographs indicated greater bone loss in the control group compared to the experimental group (3.2 ± 0.45 mm and 2.75 ± 0.55 mm, respectively). Despite the better results obtained for the Cht-coated surface group, further preclinical studies are necessary to confirm these results.

Evaluation of different surface treated implants after provisionalization: A 6-month prospective study.

Replacing missing teeth with dental implants has become the best treatment option; therefore, clinicians need to understand the predictability of the treatment. Surface treatment of implants is one of the methods to improve osseointegration, thus improving the quality of treatment. Increasing esthetic awareness among patients has led to the popularity of immediate provisionalization of dental implants. This study investigated the effect of surface treatment on implant stability when loaded with immediate non-functional temporary prostheses and compared the superiority of one surface treatment over the other in terms of osseointegration by evaluating implant stability quotient (ISQ). Twenty implants with different surface treatments were placed, i.e., resorbable blast media (RBM) surface and alumina blasted/acid-etched (AB/AE) surfaces. All the implants were non-functionally loaded, and ISQ was measured immediately after implant placement and 6 and 12 weeks after non-functional loading. Crestal bone levels, mPI, mSBI, and peri-implant probing depths were compared for both groups at 1, 3, and 6 months. At 12 weeks, all the implants showed desirable ISQ, indicating successful osseointegration. The increase in ISQ at 12 weeks was significantly higher for RBM implants compared to baseline, indicating a more predictable course of osseointegration. Crestal bone levels recorded at 1, 3, and 6 months did not significantly differ between the groups. All other parameters showed comparable values for both groups at all intervals. Replacing missing teeth with dental implants with immediate non-functional restorations is a predictable treatment option.

Influence of Crestal Implant Position and Smooth Collar on Marginal Bone Level: A 2-Year Retrospective Radiographic Analysis.

The aim of this retrospective study was to establish the survival rate and the clinical outcome of a an endoosseous implant system and to evaluate the marginal bone level and the impact of the positioning of the machined collar neck on crestal bone level changes up to two years follow-up. 96 implants were placed in 57 patients and loaded with final restoration after at least three months of healing time. 15 of these implants were immediately placed into fresh extraction sockets while 81 implants were inserted in healed ridges. Marginal Bone Loss around implants were determined radiographically after a mean observation time ranging between twelve and twenty-four months after loading. The effect of location (mandible v/s maxilla, anterior v/s posterior), immediate implant v/s native bone, smoking habit, gender, implant length and diameter, the type of prosthesis (screw-retained/cemented) and the positioning of the machined collar on the marginal bone loss was evaluated. Survival rates were evaluated based on the criteria as determined by Misch et al. in 2008. The Survival Rate at the implant level was 98, 96% at 1 year follow-up period. The mean marginal bone level has significantly changed over time in the overall sample after a follow-up period of one year (-p-value<0.001); it (average) decreased significantly by 0.238 mm between baseline and loading (-p-value<0.001; post-hoc test). It also decreased by 0.154 mm between loading and 1 year, however the decline was not significant (-p-value=0.085; post-hoc tests). After a follow-up period of two years, the mean marginal bone level has significantly changed over time in the overall sample (-p-value<0.001); it has decreased significantly by 0.263 mm between baseline and loading. It (Average) has also decreased by 0.111 mm between loading and 1 year and by 0.199 mm between loading and 2 years, but these declines were not significant (-p-value>0.05; post-hoc tests). The mean bone loss after 1-year and 2 years was not significantly associated with implants type, implant site (maxilla/mandible or anterior/posterior implants), smoking habits and type of implant's surgery (-p-value=0.792).However, it was significantly associated with the type of prosthesis; it was significantly elevated with cemented prosthesis compared to screw-retained prosthesis. A supracrestal positioning of the machined collar (tissue level placement) was associated with no bone loss, while placing the smooth part of the implant below the alveolar crest has led to bone loss over 2 years. Marginal bone loss after 1 and 2 years was not significantly associated with implants type, implant site (maxilla/mandible or anterior/posterior implants), smoking habits and type of surgery. However, it was significantly elevated with cemented prosthesis compared to screw-retained prosthesis. It was dependent also on the positioning of the machined collar.

Radiographic bone level and soft tissue dimensional changes following explantation of implants affected by peri-implantitis: A retrospective exploratory evaluation.

While the dimensional alteration of alveolar bone following tooth extraction have been extensively descripted in the literature, no information is available regarding potential hard and soft tissues changes following implant explantation. To evaluate the radiographic bone healing and the horizontal and vertical soft tissue dimensional alterations at implant extraction alveoli, 6 months following implant explantation. Data from 31 patients scheduled for extraction of one implant with persisting peri-implantitis despite treatment were analysed. Bone crest level changes and the extent of bone healing at the apical aspect of the implant socket were assessed on the radiographs prior and 6 months following explantation. Regression analyses assessed the impact of various predictors (e.g., bone crest level, presence/absence of buccal bone) on bone level changes. Fisher's exact probability test was applied to assess the difference in probability to have mucosa recession of ≥2 mm in the presence or absence of alveolar buccal bone. A vertical bone loss of 0.8 mm (standard deviation [SD] = 1.3) of the peri-implant bone crest and a gain of 0.8 mm (SD = 1.1) from the bottom of the peri-implant defect were recorded. Complete healing was noted in the intact implant extraction socket (i.e., the part of the implant not affected by peri-implantitis). A reduction of 0.4 mm (SD = 0.7) of the alveolar mucosa height was recorded in concomitant with a decrease of 0.7 mm (SD = 0.8) of the mucosa width. These alterations were more pronounced in the absence of the alveolar buccal bone. The results of the present explorative study indicated a decrease in the height and width of the alveolar soft and hard tissues following explantation of peri-implantitis affected implants, and these changes were more pronounced in the absence of the buccal bone wall. Nevertheless, the apical portion of the implant alveolus (the intact implant socket) tend to heal with no further bone loss.

CBCT Compared to Transgingival Probing as a Tool for Estimating Alveolar Bone Crest Level in Patients with Altered Passive Eruption.

Alveolar bone crest level is essential in determining the need for bone removal in subjects with altered passive eruption (APE). This study assessed the validity of Cone Beam Computed Tomography (CBCT) and transgingival probing. Patients presenting with APE were assessed. Transgingival probing was performed to clinically assess the distance between the cementoenamel junction (CEJ) and the crest of the bone at the mid-point of upper anterior teeth. CBCT was used to assess this distance at the same point. Upon reflection of a full mucoperiosteal flap the actual distance was measured. Similar actual and CBCT measurements of the distance between the CEJ and bone crest at upper right 3, upper left 2 and upper left 3 (P>0.05) were recorded. However, in upper right 2, upper right 1 and upper left 1 the distance was significantly greater on CBCT (P<0.05). No significant difference was detected between transgingival probing and the actual distance at all teeth assessed. Careful transgingival probing provides an accurate measure of the distance between the CEJ and crest of the Bone. CBCT gives an accurate estimate, However, it might not be justified for each patient in the presence of safer methods.