The thickness of labial bone affects the esthetics of immediate implant placement and provisionalization in the esthetic zone: A prospective cohort study

Feasibility of Immediate, Early and Delayed Implant Placement for Single Tooth Replacement in the Premaxilla: A Retrospective Cone-Beam Computed Tomography Study of 100 Cases

AIM

To assess the feasibility of immediate (IIP), early (EIP) and delayed implant placement (DIP) for single tooth replacement in the premaxilla on the basis of the complete indication area of each approach in routine practice.

MATERIALS AND METHODS

Data from 100 patients (59 women, 41 men, all Caucasians) aged between 19 and 81 years old (mean age 51.71) who had been consecutively treated with a single implant in the premaxilla (13-23) in one private periodontal practice were retrospectively collected. Demographic data, diagnostic information and linear measurements were extracted from patient files and CBCTs. The feasibility of IIP, EIP and DIP was assessed for all cases by both authors, based on the following criteria: availability of apical bone, position of the tooth in relation to the morphology of the alveolar process, buccal bone morphology and presence of midfacial recession. The reasons for not being able to perform an approach, and the viable alternatives for each approach were secondary outcomes. DIP was considered to have been preceded by alveolar ridge preservation (ARP).

RESULTS

Ninety-two patients could be treated by means of IIP, EIP or DIP. In eight patients none of these approaches were possible as they required bone augmentation prior to implant placement. Fifty-two patients (95% CI: 42%-62%) could by treated with IIP, 58 (95% CI: 48%-67%) with EIP and 88 (95% CI: 80%-93%) with DIP. The feasibility proportions of IIP and EIP were significantly lower than the one of DIP (p < 0.001). All patients who could be treated with IIP could also be treated with EIP or DIP. Lack of apical bone for implant anchorage was the main reason for not being able to perform IIP and EIP. Complete loss of the buccal bone wall and the need for bone augmentation prior to implant placement were the reasons for not being able to perform DIP.

CONCLUSION

From the results of this retrospective CBCT analysis, DIP is nearly always possible in contrast to IIP and EIP. Therefore, and since it is much easier than IIP and EIP, inexperienced clinicians should mainly focus on ARP and DIP in clinical practice deferring IIP and EIP until more surgical skills have been acquired.

Evaluation of buccal bone resorption in immediate implant placement in thin versus thick buccal bone plates: An 18-month follow-up prospective cohort study

OBJECTIVES

The current guidelines recommend that immediate implants be placed in patients with thick (>1 mm) buccal bone due to the inevitable tissue remodeling that follows tooth extraction. The aim of the current study was to investigate the effect of buccal bone thickness on bone resorption in immediate implant placement and compare two measuring techniques of the aforementioned resorption.

MATERIALS

The present study was designed as a prospective nonrandomized, controlled clinical trial. A total of 30 implants were split between the two study arms, thin buccal bone and thick buccal bone. The primary outcome was to assess vertical bone changes radiographically by cone beam scans preoperatively, at 2 months and 18 months after implant placement in patients with thin and thick buccal plate. Secondary outcomes included the change in the thickness of the buccal bony plate, marginal bone loss, and pink esthetic score.

RESULTS

Only 26 implants were statistically analyzed as one early failure was observed in each group. Furthermore, 2 patients of the thick group withdrew from the study. Cone beam computed tomography measurements revealed that at 2 months the vertical bone loss was 1.09 for the thin group and 0.85 for the thick group. The buccal bone plate resorption of the thin group was 0.39 mm while it was 0.52 mm for the thick group. The buccal bone plate was 1.25 mm in the thin group and 1.88 mm in the thick group. The PES did not show any significant difference with very good esthetic results.

CONCLUSION

Within the limitations of the current study, the amount of buccal bone plate resorption and the subsequent thickness obtained after implantation in both groups suggest successful long-term results. The two measuring techniques have proven to be comparable and reliable in the measurement of buccal bony plate changes. https://classic.

CLINICALTRIALS

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Posterior open wound healing in immediate implant placement using reactive soft tissue versus absorbable collagen sponge: a retrospective cohort study

The soft and hard tissue healing of open wounds in immediate implant placement are yet to be explored. The aim of this study was to compare the clinical outcomes of open wound healing using reactive soft tissue (RST) and absorbable collagen sponge (ACS). Forty implants placed immediately in posterior sockets were included; autologous RST was used in 20 and ACS substitute was used in 20. Soft tissue healing was primarily assessed through a novel scoring system and the evaluation of gingival recession. The horizontal bone width (HBW) and interproximal marginal bone level (MBL) were measured on radiographs to observe the hard tissue healing. No significant difference in total soft tissue healing score was observed at 2 weeks postoperatively. Notably, the ACS group showed better tissue colour (P = 0.016) but worse fibrous repair (P = 0.043) scores than the RST group. Gingival recession levels were comparable in the two groups, both before tooth extraction and after placement of the restoration. Regarding hard tissue, HBW and MBL changes showed no intergroup differences. Within the limitations of this study, both RST and ACS seemed effective for open wound closure, achieving ideal soft and hard tissue healing in immediate implant placement.

Effectiveness of immediate implant placement into defective sockets in the esthetic zone: A systematic review and meta-analysis

STATEMENT OF PROBLEM

A defective socket is common after tooth extraction in the esthetic zone, but whether an implant can be immediately placed in a defective socket is unclear.

PURPOSE

The purpose of this systematic review and meta-analysis was to summarize relevant studies within the last 20 years on implant survival and changes in soft and hard tissues after immediate implant placement in esthetic areas with socket defects.

MATERIAL AND METHODS

A search was conducted for the relevant studies in the PubMed/Medline, the Cochrane Library, Web of Science, and Embase databases from January 2000 to March 2022. The literature review, data retrieval, and judgment whether the included studies had a risk of bias were handled independently by 2 reviewers, and a single-arm meta-analysis was performed using a statistical software program.

RESULTS

A total of 23 studies evaluating the immediate implant placement of 630 implants (9 studies without a flap and 14 studies with a flap) were included. A 98.1% implant survival rate (95% confidence interval (CI): 96.2%, 100.0%) was determined. Marginal bone loss (MBL) at 6, 12, and ≥24 months were 1.03 mm (95%CI: 1.02, 1.03), 0.72 mm (0.72, 0.73), and 1.15 mm (1.14, 1.16). Gingival recession at 12 months was 0.25 mm (95%CI: 0.17, 0.33). The pink esthetic score (PES) were 12.34 (95%CI: 12.16, 12.52) at 12 months and 12.58 (12.39, 12.76) at ≥24 months.

CONCLUSIONS

Current evidence shows that immediate implant placement into defective sockets in esthetic areas is feasible. Immediate implant placement can have a relatively good therapeutic effect in terms of implant survival rate, MBL, gingival recession, and PES.

Clinical outcomes of narrow- and regular-diameter implants with bone augmentation in the anterior maxilla: a systematic review and meta-analysis

OBJECTIVES

To evaluate the clinical outcomes of narrow-diameter implants (NDIs) and regular-diameter implants (RDIs) with bone augmentation in the anterior maxilla, with implant survival rate (ISR) as the primary outcome. Additionally, secondary outcomes such as peri-implant marginal bone loss (MBL), pocket probing depth (PPD), mechanical complications, and biological complications were also considered.

MATERIALS AND METHODS

A thorough literature search was performed to identify randomized controlled trials and cohort studies comparing outcomes of NDIs and RDIs with bone augmentation in the anterior maxilla published up to February 2024. Only studies with a minimum follow-up period of 12 months were selected for analysis. Meta-analysis was performed if at least two articles with similar characteristics were available.

RESULTS

Of the 288 articles initially considered, 5 were included in the analysis, involving 282 NDIs and 100 RDIs. At the 36-month follow-up, no statistically significant differences in ISR, which ranged 93.8-100% for NDIs and were 100% for RDIs, were observed between the two groups (relative risk, 0.989; 95% confidence interval, 0.839-1.165; p = 0.896). Similarly, MBL and PPD did not differ significantly between the two groups. Soft tissue dehiscence was the most common complication found in RDIs.

CONCLUSION

The results indicate that NDIs yield clinical outcomes similar to those of RDIs with bone augmentation in the anterior maxilla over a 36-month follow-up period.

CLINICAL RELEVANCE

Considering the similar clinical outcomes, the shortened treatment duration and more rapid esthetic improvement associated with NDIs may render them preferrable to RDIs with bone augmentation, particularly in this esthetic zone.

Clinical performance of immediately placed and immediately loaded single implants in the esthetic zone: A systematic review and meta-analysis

OBJECTIVES

The aim of this study was to assess the following PIO question: In adult patients treated with an indication for single tooth extraction in the maxillary esthetic zone (15-25), what is the influence of an immediate implant placement and immediate loading protocol on the clinical performance (primary aim) and esthetic outcomes (secondary aim) focusing on investigations published after 2010.

MATERIAL AND METHODS

An electronic search in Medline (PubMed), the Cochrane Central Register of Controlled Trials, and EMBASE databases up to April 2022 was performed to identify clinical studies investigating the outcome of single implants subjected to immediate placement with immediate restoration/loading (Type 1A).

RESULTS

Sixty-three studies (10 randomized controlled trials, 28 prospective and 25 retrospective cohort studies) were included with a follow-up ranging from 12 to 96 months. One thousand nine hundred sixty-one implants reported survival rates of 99.2 (98.6-99.5) % at 1 year, 97.5 (95.9-98.4) % after 3 years, and 95.8 (93.3-97.4) % after 5 years; 1064 immediately loaded restorations presented survival rates of 98.9 (97.8-99.5) % after 1 year, 96.8 (93.6-98.4) % after 2 years, and 94.8 (89.6-97.4) % after 5 years. Comparing baseline to 12-month data using the Hedges' g effect size (95% CI), papilla height presented an overall effect size of -0.71 (-1.25, -0.1) mm, midfacial recession change of -0.15 (-0.66, 0.36) mm, and a 0.82 (0.37, 1.28) gain in PES.

CONCLUSIONS

Immediate implant placement and immediate loading can be considered a predictable and safe treatment option for single maxillary anterior restorations with adequate survival rates and favorable esthetics outcomes for up to 5 years.

Selection criteria for immediate implant placement and immediate loading for single tooth replacement in the maxillary esthetic zone: A systematic review and meta-analysis

OBJECTIVES

The aim of this study was to review available evidence for Type 1A (immediate implant placement and immediate loading) of single tooth replacement in the maxillary esthetic zone.

MATERIALS AND METHODS

An electronic search was conducted utilizing the databases of MEDLINE, Embase, and Cochrane to identify publications reporting on the outcomes of Type 1A for single tooth replacement in the maxillary esthetic zone. The success and survival rates of the included articles were reported, which were further categorized according to the clinical criteria reported in Type 1A. Mean survival rates were univariately compared between risk groups and additionally between studies published before and since 2012 using bias-corrected and study size-weighed bootstrap tests. A study time-correcting meta-analysis was then performed to obtain an overall effect for the study pool.

RESULTS

A total of 3118 publications were identified in the search, with a total of 68 articles included. A mean number of implants per study were 37.2 and mean follow-up was 2.8 years. All the included studies utilizing Type 1A report highly selective inclusion and exclusion criteria. Univariate risk group comparison determined that studies before 2012 report a significantly lower mean survival rate (difference of -1.9 percentage points [PP], 95% CI: [-0.3, -4.0], p = .02), facial gap dimension had an impact on survival rates (+3.1 PP [0.2, 5.3] for width >2 mm, p = .04), as well as presence of endodontic infection (+2.6 PP [0.9, 5.1], p = .004).

CONCLUSIONS

Type 1A has a high survival rate in studies reporting strict patient and site selection criteria. Further research is required to assess esthetic and functional success with Type 1A treatments.

Effectiveness and complications of transcrestal sinus floor elevation using the cushioned grind-out technique: A retrospective cohort study with up to 7 years of follow-up

AIM

To evaluate the effectiveness and complications of the cushioned grind-out technique. The primary outcome was endo-sinus bone gain (ESBG), while secondary outcomes included the Schneiderian membrane perforation rate and mid- to long-term implant survival.

MATERIALS AND METHODS

In this retrospective study, we compared the cushioned grind-out technique with the classic osteotome technique, establishing statistical models to assess ESBG, membrane perforation rate and implant survival rate.

RESULTS

A total of 259 patients and 340 implants were included. The mean ESBG was 5.31 mm for the cushioned grind-out group and 4.64 mm for the osteotome group. Multivariable regression analysis revealed that the cushioned grind-out technique significantly facilitated ESBG (p = .028). Nineteen preparation sites experienced membrane perforation, with rates of 5.5% and 6.4% for the cushioned grind-out and osteotome groups, respectively. However, the difference was not statistically significant (p = .920). Additionally, the cumulative survival rate of the implants for 7 years was 95.2% and 91.4%, respectively, with the surgical technique not significantly influencing the results.

CONCLUSIONS

With 6 months to 7 years of post-prosthetic restoration review data, our findings show that the cushioned grind-out technique facilitates a higher ESBG, with no significant difference in membrane perforation or implant failure rate.

Buccal bone thickness and mid-facial soft tissue recession after various surgical approaches for immediate implant placement: A systematic review and network meta-analysis of controlled trials

AIM

To evaluate the relative efficacy and confidence in the precision of the results of different surgical interventions for immediate implant placement in the anterior area.

MATERIALS AND METHODS

Electronic searches were performed in PubMed, Embase, and Cochrane CENTRAL. Randomized controlled trials comparing different surgical techniques in anterior jaws for type 1 implant placement were included. Outcome measures included implant survival (primary outcome), buccal bone thickness (BBT) reduction, and mid-facial soft tissue recession (MSTR). Risks of bias assessment, network meta-analysis (NMA), sensitivity analysis, and quality-of-evidence assessment were performed.

RESULTS

Twenty-two studies reporting on 948 subjects and 5 surgical interventions were included. Fourteen early failures were reported. Compared with open-flap surgery without tissue augmentation (F-N) and looking at BBT preservation, NMA showed that there was moderate confidence that flapless surgery with hard tissue augmentation (FL-HTA) was better than flapless surgery without tissue augmentation (FL-N) or open-flap surgery with hard tissue augmentation (F-HTA) (mean difference -0.8 mm, 95% confidence interval: -1.1 to -0.5 mm; -0.6 mm, -0.9 to -0.4 mm; and -0.5 mm, -0.7 to -0.3 mm, respectively). There was moderate confidence that flapless surgery with hard and soft tissue augmentation (FL-HTA&STA) could significantly prevent MSTR compared with FL-HTA (-0.5 mm, -0.7 to -0.3 mm) and FL-N (-0.6 mm, -1.2 to -0.04 mm). However, there was no significant additional benefit in BBT with the FL-HTA&STA approach compared to the FL-HTA approach (-0.30 mm, -0.81 to 0.21 mm).

CONCLUSIONS

For immediate implant placement in the anterior areas, the FL-HTA approach better preserves BBT (moderate confidence); adding STA improves the stability of the mid-facial soft tissue level (moderate confidence) but at the expense of BBT (low confidence).

Outcomes of bio-esthetic single implant-supported restorations after peri-implant soft tissue conditioning with two prosthetic techniques: A 1-year randomized clinical trial

STATEMENT OF PROBLEM

Providing a definitive restoration with an emergence profile matching that of the contralateral or extracted tooth should result in an esthetic peri-implant soft tissue contour. Whether a custom healing abutment improves the outcome of a bio-copied definitive restoration compared with a stock abutment is unclear.

PURPOSE

The purpose of this 1-year randomized clinical trial was to evaluate the peri-implant soft and hard tissues related to bio-esthetic single implant-supported restorations having a contralateral tooth-matching restorative emergence profile after peri-implant soft tissue conditioning with either custom or stock healing abutment for patients indicated for immediate implant placement.

MATERIAL AND METHODS

Twenty-four participants indicated for immediate implant placement in the maxillary esthetic zone received bio-esthetic single implant-supported restorations after peri-implant soft tissue conditioning with either a custom healing abutment (n=12) or a stock healing abutment (n=12). The pink and white esthetic score (PES-WES) was evaluated 6 and 12 months after implant placement. Peri-implant bone changes were measured with cone beam computed tomography (CBCT) scans at the same intervals.

RESULTS

The PES-WES showed significant difference between the 2 groups at 6 and 12 months. The CBCT scans did not show significant difference between the 2 groups.

CONCLUSIONS

The use of the bio-esthetic concept for immediate single implant placement achieved successful esthetic restorations after conditioning the peri-implant tissues using either custom or stock healing abutments. However, the use of custom healing abutments was associated with higher PES-WES values in comparison with the use of stock healing abutments.

Immediate implant placement with flap or flapless surgery: A systematic review and meta-analysis

AIM

To assess the impact of mucoperiosteal flap elevation for single immediate implant placement (IIP) on buccal hard and soft tissue changes, and on clinical, aesthetic and patient-reported outcomes.

MATERIALS AND METHODS

Two independent reviewers conducted an electronic literature search in Pubmed, Web of Science, Embase and Cochrane databases as well as a manual search to identify eligible clinical studies up to June 2022. Randomized controlled trials (RCTs) comparing IIP without flap elevation to IIP with flap elevation were included for a qualitative and quantitative analysis. The primary outcome was horizontal buccal bone change. Secondary outcomes were implant survival, vertical buccal bone change, pain, and clinical and aesthetic parameters.

RESULTS

Out of 1029 records, 5 RCTs were selected reporting on 140 patients who received 140 single immediate implants (flapless: 68; flap: 72). Patients had a mean age ranging from 30 to 67 years and were followed between 6 and 12 months. Four RCTs pertained to (nearly) intact alveoli. Risk of bias assessment yielded low risk for two RCTs and high risk for three RCTs. Meta-analysis demonstrated a mean difference of 0.48 mm (95% confidence interval [CI] [0.13, 0.84], p = .007) in horizontal buccal bone change between surgical approaches, favouring flapless surgery. Meta-analysis failed to demonstrate a significant difference in implant survival between the groups (RR 1.00, 95% CI [0.93, 1.07], p = .920). Given the scarcity of data, meta-analyses could not be performed on other secondary outcomes. Available studies were consistent in the direction of the effect favouring flapless surgery for vertical buccal bone change as well as for pain. Clinical and aesthetic parameters were underreported.

CONCLUSIONS

Based on CBCT data, flapless surgery resulted in more buccal bone preservation at immediate implants. However, the clinical relevance of this finding is unclear, since clinical and aesthetic outcomes were underreported.

Efficacy of soft tissue augmentation procedures on tissue thickening around dental implants: A systematic review and meta-analysis

OBJECTIVES

The first focused question (FQ1) was: What is the efficacy of connective tissue graft (CTG), as compared to the absence of soft tissue grafting procedure, in terms of gain in peri-implant soft tissue thickness (STT) reported by randomized controlled clinical trials (RCTs) or controlled clinical trials (CCTs)? The second focused question (FQ2) was: What is the efficacy of CTG, as compared to soft tissue substitutes, in terms of gain in peri-implant STT reported by RCTs or CCTs?

MATERIALS AND METHODS

A manual and electronic search was performed for each question to identify RCTs and CCTs published up to July 2020. The primary outcome variable was changes in peri-implant STT and secondary outcomes were marginal bone level (MBL), clinical parameters for the diagnosis of peri-implant health, changes in the position of peri-implant soft tissues, esthetic outcomes, and patient-related outcome measures (PROMs). For primary and secondary outcomes, data reporting mean values and standard deviations for each study were extracted. Weighted mean differences (WMDs) or standardized mean differences as well as 95% confidence intervals (CIs) and prediction intervals (PIs) were calculated.

RESULTS

Eight trials were included to answer the first focused question and eight to answer the second one, providing data for 254 and 192 patients, respectively. For the first focused question, a statistically significant difference of 0.64 mm in STT was found in favor of the grafted group (n = 8; 95% CI [0.16; 1.13]; 95% PI [-1.06; 2.35]; p = .01). Moreover, sites treated with CTG exhibited statistically significant less recession than implants without a graft (n = 4; WMD = 0.50 mm; 95% CI [0.19; 0.80]; 95% PI [-0.70; 1.69]; p < .001). For the second focused question, the meta-analysis showed a statistically significant gain of STT in the CTG group when compared to soft tissue substitutes (n = 8; WMD = 0.51 mm; 95% CI [0.28; 0.75]; 95% PI [-0.09; 1.12]; p < .001). Furthermore, the use of CTG resulted in significantly higher pink esthetic score values (n = 3; WMD = 1.02; 95% CI [0.29; 1.74]; 95% PI [-3.67; 5.70]; p = .01) and less recession (n = 2; WMD = 0.50 mm; 95% CI [0.10; 0.89]; 95% PI [not estimable]; p = .014) when compared to soft tissue substitutes. No statistically significant differences between groups were observed for any of the following secondary variables: MBL, clinical parameters for the diagnosis of peri-implant health, position of the interproximal tissues, keratinized mucosa or PROMS (p > 0.05), except for medication intake, which was significantly higher when using CTG as compared to soft tissue substitutes (n = 2; WMD = 1.68; 95% CI [1.30; 2.07]; 95% PI [not estimable]; p < .001).

CONCLUSIONS

Soft tissue augmentation procedures are efficacious on soft tissue thickening and, in particular, CTG demonstrated a significant STT gain when compared to no graft or soft tissue substitutes.

Average and Maximum Papilla Heights around Dental Implants in the Anterior Maxillary Region: A Retrospective Clinical Study

Objective

The aim of this study was to determine the average and maximum height of the papilla around maxillary anterior implants in respect of neighboring structures and location of implants.

Materials and Methods

92 dental implants from 63 patients were investigated in this study. Those implants were placed in the anterior maxillary region and had been loaded for a minimum of one year. After receiving written consent, clinical data including the height of interproximal papillae adjacent to the tooth/implant/pontic were obtained through clinical observation. The independent t-test or ANOVA, the regression modeling, and generalized estimating equation (GEE) models were used for statistical analysis (p < 0.05).

Results

Papilla height was calculated as 2.8 mm (1–5.5 mm) for implant-tooth sites, 2.6 mm (1–4 mm) in implants beside pontics, and 2.5 mm (1–3.5 mm) for implants adjacent to implants. Despite the lack of a significant difference in the mean papilla height in the studied groups, the maximum values of papilla heights were significantly different.

Conclusions

In this study, no significant differences were found in papilla height mean values in relation to neighboring structures or location of implants in the anterior maxilla. However, the maximum values of papilla heights were observed around implants next to natural teeth.

Thickness of the Buccal and Alveolar Bones Overlying Central Incisors: A Radiographic Iraqi Study

Background. Initial bone thickness has a substantial impact on the success of dental implant treatments. The objective of the current study was to analyze the thickness of the buccal and alveolar bone at the central incisors using CBCT in relation to gender and side to determine the anatomical features and choose the best implant treatment option for minimizing the surgical complications. Methods. One hundred CBCT images were investigated (50 females and 50 males, aged 20 to 50 years old). The buccal bone thickness and alveolar bone thickness were evaluated for right and left sides of each subject at three sites; C: crest (3 mm); M: middle (6 mm); A: apical (9 mm) from the cementoenamel junction. Results. The mean thickness of buccal bone was less than 2 mm on the incisors according to side and gender. Buccal bone thickness revealed a statistically significant difference between right and left sides at the apical point in both females and males with $p$ values of ( $p\le 0.001$ ) and (0.001), respectively. The buccal bone thickness displayed statistically significant differences between genders at all sites. The alveolar thickness demonstrated similar significant differences between genders except for the crest site. Conclusions. Iraqi participants had about 1 mm buccal bone thickness at 3 mm apical from the CEJ in right and left central incisors with a progressive rise in bone thickness to be less than 2 mm at the apex. Alveolar bone also showed the same increase in bone thickness from crest to apex. Bone thickness was greater in males than females. The present study provided valuable CBCT data on bone thickness of the esthetic maxillary region as a preoperative analysis for establishing an immediate implant treatment plan with aesthetically pleasing long-term outcomes.

Buccal bone dimensional changes at immediate implant sites in the maxillary esthetic zone within a 4-12-month follow-up period: A systematic review and meta-analysis

OBJECTIVE

To evaluate the changes in buccal bone dimensions (CBD) following immediate implant placement in the maxillary esthetic zone and to identify the factors influencing the degree of buccal bone resorption for different placement and restoration protocols.

MATERIAL AND METHODS

An electronic search was conducted using the EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), and MEDLINE (PubMed) databases, combined with a manual and gray literature search, up to January 2021. Selected clinical studies had to report the changes in horizontal buccal bone dimension in maxillary immediate implantation sites (premolar to premolar) at baseline and at follow-up visits within a year of implantation. A meta-analysis was conducted to calculate the mean value of the changes in horizontal and vertical buccal bone dimensions (CHBD and CVBD) around implants. To further investigate the heterogeneity and identify factors associated with buccal bone loss after immediate implant placement, subgroup analysis and univariate meta-regression were performed.

RESULTS

From a total of 3498 articles, 4 randomized controlled trials and 12 nonrandomized controlled trials were included for analysis. The mean survival rate of 568 implants was 99.6%. The mean CHBD and CVBD values were 0.71 mm (95% confidence interval: [0.56, 0.86]) and 0.58 mm (95% confidence interval: [0.43, 0.72]), respectively. For possible factors that related to bone resorption, including buccal bone thickness, flap design, bone grafting, horizontal defect dimension, and restoration protocol, bone grafting was the only variable that significantly influenced CHBD.

CONCLUSIONS

This study demonstrated that immediate implant placement in the esthetic zone does not prevent buccal bone from resorption. Due to data heterogeneity and the small sample size of the studies included in the analysis, further well-conducted, randomized controlled trials with homogeneous samples are required to investigate the correlation of CBD with different variables.

Evaluation of the accuracy of buccal bone thickness measurement from cone beam computed tomography compared with histologic analysis

STATEMENT OF PROBLEM

Three-dimensional radiographic assessment of buccal bone thickness and its integrity from cone beam computed tomography (CBCT) plays an essential role in immediate implant placement. However, the accuracy of CBCT measurements for the assessment of buccal bone thickness adjacent to maxillary anterior teeth is not well understood.

PURPOSE

The purpose of this observational study was to evaluate the accuracy of measuring the buccal bone thickness of maxillary anterior teeth from CBCT compared with direct measurement from histologic sections. A secondary objective was to analyze whether a minimal level of buccal bone thickness of maxillary anterior teeth can be detected from the CBCT scan.

MATERIAL AND METHODS

Five embalmed human cadavers with a complete anterior dentition were included in this study, providing 30 teeth for evaluation. After preparing reference notches at the gingival margin of each tooth, the anterior segments were scanned. The buccal bone thickness at 3, 5, and 7 mm from the notches was measured on the cross-sections obtained from the CBCT and histomorphometric images for a total of 90 sites. The CBCT measurements were compared with the histomorphometric measurements, and their agreement was assessed by using the Bland-Altman plots and intraclass correlation coefficients. The sensitivity and specificity of buccal bone detection were calculated from the CBCT scan.

RESULTS

Histologic examination showed absence of the buccal bone in 29 sites (32%). The mean ±standard deviation thickness of the buccal bone was 0.52 ±0.05 mm (range: 0 to 1.97 mm) from the CBCT analysis and 0.40 ±0.05 mm (range: 0 to 1.67 mm) from histology. Measurements obtained from the CBCT sections significantly overestimated the buccal bone thickness when compared with the histologic evaluation (P=.001). The intraclass correlation coefficient of buccal bone thickness between the CBCT and histology was ≤0.53, an agreement considered as poor. The sensitivity of the CBCT as a diagnostic tool to detect the presence or absence of the buccal bone was 75.4%, and the specificity was 65.5%.

CONCLUSIONS

The buccal bone thickness of maxillary anterior teeth was less than 2 mm at all sites as measured with both CBCT and histology evaluations. CBCT measurements had relatively low accuracy and reliability for the measurement of buccal bone thickness. These findings should be considered when using CBCT as a measuring tool for thin bone structures.

Clinical efficacy of mineralized collagen (MC) versus anorganic bovine bone (Bio-Oss) for immediate implant placement in esthetic area: a single-center retrospective study

BACKGROUND

The purpose of this retrospective study was to evaluate the clinical efficacy of mineralized collagen (MC) versus anorganic bovine bone (Bio-Oss) for immediate implant placement in esthetic area.

METHODS

Medical records of Department of Oral and Maxillofacial Surgery of Shandong Provincial Hospital were screened for patients who had been treated with immediate implant implantation in the esthetic area using either MC (Allgens®, Beijing Allgens Medical Science and Technology Co., Ltd., China) or Bio-Oss (Bio-Oss®, Geistlich Biomaterials, Wolhusen, Switzerland), between January 2018 and December 2019. All patients fulfilling the in-/exclusion criteria and following followed for a minimum period of 1 year after surgery were enrolled into the presented study. Implant survival rate, radiographic, esthetic and patient satisfactory evaluations were performed.

RESULTS

Altogether, 70 patients were included in the study; a total of 80 implants were inserted. All implants had good initial stability. The survival rate of implants was 100% at 1-year follow-up. The differences in horizontal and vertical bone loss between the MC group (0.72 ± 0.26 mm, 1.62 ± 0.84 mm) and the Bio-Oss group (0.70 ± 0.52 mm, 1.57 ± 0.88 mm) were no significant difference statistically no significant 6 months after permanent restoration. Similar results occurred at 12 months after permanent restoration functional loaded. Clinical acceptability defined by pink esthetic score (PES) ≥ 6 (6.07 ± 1.62 vs. 6.13 ± 1.41) was not significantly different between groups. Patient satisfaction estimated by visual analog scale (VAS) was similar (8.56 ± 1.12 vs. 8.27 ± 1.44), and the difference was no significant difference between the two groups.

CONCLUSIONS

The biomimetic MC showed a similar behaviour as Bio-Oss not only in its dimensional tissues changes but also in clinical acceptability and patient satisfaction. Within the limitations of this study, these cases show that MC could be considered as an alternative bone graft in IIP.

Efficacy of bone-substitute materials use in immediate dental implant placement: A systematic review and meta-analysis

OBJECTIVE

To assess the efficacy of using a bone substitute material (BSM) in the fixture-socket gap in patients undergoing tooth extraction and immediate implant placement.

MATERIALS AND METHODS

MEDLINE, EMBASE, and CENTRAL databases were searched for randomized controlled trials (RCTs). RCTs were screened for eligibility, and data were extracted by two authors independently. Risk of bias (ROB) was assessed using Cochrane's ROB tool 2.0. Primary outcomes were implant failure, overall complications, and soft-tissue esthetics. Secondary outcomes were vertical buccal bone resorption, vertical interproximal bone resorption, horizontal buccal bone resorption, and mid-buccal mucosal recession. Meta-analysis was performed using random-effects model with generic inverse variance weighing. GRADE was used to grade the certainty of the evidence.

RESULTS

After screening 19 544 potentially eligible references, 20 RCTs were included in this review, with a total of 848 patients (916 sites). Most included RCTs were deemed of some concerns (53%) or at low (38%) risk of bias, except for overall complications (high ROB). Implant failure did not differ significantly RR = 0.92 (confidence intervals [CI] 0.34 to 2.46) between using a BSM compared with not using a BSM (NoBSM). BSM use resulted in less horizontal buccal bone resorption (MD = -0.52 mm [95% CI -0.74 to -0.30]), a higher esthetic score (MD = 1.49 [95% CI 0.46 to 2.53]), but also more complications (RR = 3.50 [95% CI 1.11 to 11.1] compared with NoBSM. Too few trials compared types of BSMs against each other to allow for pooled analyses. The certainty of the evidence was considered moderate for all outcomes except implant failure (low), overall complications (very low), and vertical interproximal bone resorption (very low).

CONCLUSION

BSM use during immediate implant placement reduces horizontal buccal bone resorption and improves the periimplant soft-tissue esthetics. Although BSM use increases the risk of predominantly minor complications.

Evaluation of Immediate Implantation and Provisionalization Combined with Guided Bone Regeneration by a Flap Approach in the Maxillary Esthetic Zone: A Retrospective Controlled Study

The aim of this research was too compare the thickness change of labial contour and bone tissues, as well as some biological complications of immediate implantation with and without immediate provisionalization for a single anterior maxilla presenting a vertical defect on labial bone with the need of guided bone regeneration (GBR) by a flap approach. A total of 40 single implants were placed in 40 patients into fresh extraction sockets of the anterior maxilla with a vertical defect on the labial bone (<4 mm). Simultaneously, GBR was conducted at the sites by a flap approach, and the implants were given immediate or delayed provisionalization. The thickness change of bone tissues during six-month evaluation and labial contour during three and six-month follow-up were measured. Complications such as implant and restoration survival rates, infection as well as wound exposure were also evaluated at six months postoperatively. After six months, the mean thickness losses in labial bone were 0.9040, 0.8050, 0.7165, 0.5285 and 0.5335 mm at five different sites in immediate provisionalization group, and 0.8780, 0.8605, 0.7560, 0.5900 and 0.6300 mm, respectively, in delayed provisionalization group, showing no significant difference between the groups at all measurement sites. Although the labial contour changes of the two groups were similar at most sites, the values at 1 and 2 mm above the implant neck remained significantly lower in the immediate provisionalization group at three and six months postoperatively. No complications occurred during the follow-up time. Based on the limitation of this study, the immediate implantation combined with GBR, flap operation and immediate provisionalization obtained acceptable outcomes for a single anterior maxilla with vertical defect on the labial bone, but more long-term research with a larger sample are urgently needed in the future.

Facial alveolar bone thickness and modifying factors of anterior maxillary teeth: a systematic review and meta-analysis of cone-beam computed tomography studies

BACKGROUND

Understanding the anatomy of the facial alveolar bone (FAB), provides a prognostic tool for estimating the degree of dimensional ridge alterations after tooth extraction. This systematic review and meta-analysis aims to determine the FAB thickness and modifying factors of anterior maxillary teeth measured by CBCT scans. A secondary objective was to assess the facial distance from the cementoenamel junction (CEJ) to the bone crest.

METHODS

An electronic search was made of Medline, Embase, Web of Science, Cochrane Library and Google Scholar up to December 2019. Studies that analyze and quantitatively compare FAB thickness at maxillary teeth by CBCT scans were included. The methodological quality of the included studies was appraised using the ROBINS-I tool and the overall meta-evidence certainty using the GRADE approach. A single means random-effects meta-analysis was performed to obtain the weighted mean for 95% confidence interval. A meta-regression of covariates and subgroup analysis was conducted. The nullity Qh test and I2 index for heterogeneity was estimated.

RESULTS

2560 potentially relevant articles were recorded from which 29 studies were selected for the qualitative analysis, including 17,321 teeth. Seventeen studies considered the facial bone crest, and 12 the CEJ as a reference point for their measurements. Mean FAB thickness was ≤ 1 mm in maxillary incisors and canines (0.75-1.05 mm) and 1-2 mm in premolars. Patients over 50 years of age, females and thin gingival phenotype was associated with thinner FAB at some apico-coronal locations of maxillary incisors and canines. The geographical setting was an effect modifier that could explain up to 87% of the heterogeneity in FAB thickness, being Asian populations that showed the lowest FAB thickness values. The CEJ-bone crest distance was 2-2.5 mm in all teeth analyzed. Population over 50 years of age exhibited greater CEJ-bone crest distances, and males also showed a trend for greater distance. Evidence certainty has shown moderate quality in most analysis subsets.

CONCLUSIONS

Facial alveolar bone at anterior maxillary teeth is thin, heterogeneous in width along its apico-coronal dimensions, and increases in thickness in maxillary premolars. The CEJ-bone crest distance presented homogeneous and similar values in all teeth analyzed.

Non-invasive evaluation of labial gingival and alveolar crest thickness in the maxillary anterior teeth region by 15-MHz B-mode ultrasonography

Background

Knowledge of gingival thickness (GT) and alveolar crest thickness (ACT) is essential when performing surgical and non-surgical procedures in the maxillary anterior teeth region. This study aimed at evaluating the GT and ACT in the maxillary anterior teeth region using 15-MHz B-mode Ultrasonic (US).

Methods

A total of 300 teeth from 50 healthy participants, comprising 25 women and 25 men, aged between 18 and 35 years were analyzed. We measured labial periodontal tissue structures of maxillary anterior teeth, including GT and ACT, at 3 mm apical to the gingival margin (GT3) and the crestal level, respectively. The GT and ACT measurements were correlated.

Results

The mean labial GT3 of the maxillary central incisors, lateral incisors, and canines were 1.24 ± 0.03 mm, 1.21 ± 0.03 mm and 1.11 ± 0.03 mm, respectively. Canine GT3 was significantly thin than those in the central and lateral incisors (P < 0.05). With regards to labial ACT, we recorded 0.79 ± 0.03 mm, 0.76 ± 0.02 mm and 0.73 ± 0.02 mm for maxillary central incisors, lateral incisors and canines, respectively. There were no significant differences in ACT of maxillary anterior teeth (P > 0.05). GT3 of men was greater than that of women (P < 0.05). In addition, GT and ACT were positively correlated (r = 0.32, P < 0.01).

Conclusion

15-MHz B-mode US is an effective tool for measuring labial GT and ACT of anterior teeth. There are sex-associated differences in GT3 and the correlation between the GT3 and ACT of anterior teeth is moderately positive.

Immediate implant placement with or without connective tissue graft: A systematic review and meta-analysis

OBJECTIVES

To assess the effect of connective tissue graft (CTG) in terms of vertical mid-facial soft tissue change when applied at the buccal aspect following single immediate implant placement (IIP).

MATERIALS AND METHODS

Two independent reviewers conducted an electronic literature search in PubMed, Web of Science, EMBASE and Cochrane databases as well as a manual search to identify eligible clinical studies up to January 2020. Randomized controlled trials (RCTs) and non-randomized controlled studies (NRSs) comparing IIP with CTG and without CTG over a mean follow-up of at least 12 months were included for a qualitative analysis. Meta-analyses were performed on data provided by RCTs.

RESULTS

Out of 1814 records, 5 RCTs and 3 NRSs reported on 409 (IIP + CTG: 246, IIP: 163) immediately installed implants with a mean follow-up ranging from 12 to 108 months. Only 1 RCT showed low risk of bias. Meta-analysis revealed a significant difference in terms of vertical mid-facial soft tissue change between IIP + CTG and IIP pointing to 0.41 mm (95% CI [0.21; 0.61], p < .001) in favour of soft tissue grafting. This outcome was clinically relevant since the risk for ≥1 mm asymmetry in mid-facial vertical soft tissue level was 12 times (RR 12.10, 95% CI [2.57; 56.91], p = .002) lower following IIP + CTG. Soft tissue grafting also resulted in a trend towards less bleeding on probing (MD 17%, 95% CI [-35%; 1%], p = .06). Meta-analyses did not reveal significant differences in terms of pink aesthetic score, marginal bone level change and probing depth. Results were inconclusive for horizontal mid-facial soft tissue change and papilla height change. Based on GRADE guidelines, a moderate recommendation for the use of a CTG following IIP can be made.

CONCLUSION

CTG contributes to mid-facial soft tissue stability following IIP. Therefore, CTG should be considered when elevated risk for mid-facial recession is expected in the aesthetic zone (thin gingival biotype, <0.5 mm buccal bone thickness).

Analysis of Alveolar Bone Morphology of the Maxillary Central and Lateral Incisors with Normal Occlusion

Background and objectives: This study investigated the morphology of the labial and palatal bony wall of the maxillary central and lateral incisors using cone-beam computed tomography (CBCT). The difference between males and females and the measurement between right and left sides were measured. Materials and Methods: Twenty participants, consisting of 11 females and 9 males having normal occlusion, were used for the analysis. The mean age was 21.9 ± 3.0 years. The thickness of the labial bony wall and palatal bony wall, perpendicular to the long axis of the root, were evaluated at 3 and 5 mm apical from the cemento-enamel junction (CEJ) and at the root apex. The available bony wall below the apex of the central and lateral incisors, and the angulation between the long axis of the tested tooth and outer surface of the labial bone were measured. Results: The mean labial bony wall thickness at the 3 and 5 mm apical from the CEJ were 1.1 ± 0.3 mm and 1.0 ± 0.4 mm for central incisors, respectively, as well as 1.2 ± 0.4 mm and 1.0 ± 0.4 mm for lateral incisors, respectively. The mean palatal bony wall thickness at 5 mm from the CEJ was above 2 mm in the central and lateral incisors. The percentage of labial bony wall thickness 2 mm or greater at the root apex in central incisors was higher than in lateral incisors (62.5% vs. 55.0%). The percentage of palatal bony wall thickness ≥2 mm at 3 mm apical from the CEJ in the central incisors was higher than in the lateral incisors (37.5% vs. 15.0%). The results on the left and right sides did not show statistically significant differences, except in the labial and palatal bony wall thickness at 3 mm from the CEJ in the lateral incisor. Generally, no significant differences were seen between males and females, but males had a significantly higher labial bony wall thickness at 3 and 5 mm from the CEJ in the central and lateral incisors when compared with females. Conclusions: This study showed that a majority of the cases of Korean participants had less than 2 mm of labial bony wall thickness at 3 and 5 mm apical from the CEJ at central and lateral incisors, and this should be kept in mind while performing dental practices, including tooth extraction or immediate implantation in anterior regions. Preoperative analysis using CBCT may be beneficial for establishing the treatment plan.