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

Marginal bone level change of immediately restored implants with simultaneous guided bone regeneration: A systematic review

AIM

To assess marginal bone level change (MBLc), clinical outcomes for soft tissue, and survival rates for immediately restored implants with simultaneous guided bone regeneration (GBR).

MATERIALS AND METHODS

Electronic and manual searches were conducted in PubMed/MEDLINE, EMBASE, and CENTRAL for studies that investigated immediately restored implants in simultaneously grafted sites with a mean follow-up of over 12 months. MBLc was the primary outcome. Soft tissue clinical parameters and implant survival rate (ISR) were the secondary outcomes.

RESULTS

Twenty-five studies (5 randomized controlled trials, 6 prospective studies, 2 retrospective studies, and 12 case series) were included, from which 692 immediately restored implants were analyzed. For studies that investigated bone grafts in the gap between the implant and the peripheral bone wall, the weighted mean MBLc was -0.73 ± 1.52 mm (range: -1.50 to 0.26 mm) for 475 implants. Pink esthetic score (PES) was improved in eight studies and the weighted cumulative ISR was 98.99% (Median: 100%) in 622 implants. Mean MBLc was -1.19 ± 0.26 mm for 30 implants in studies that reported gap with dehiscence and/or fenestration augmentation. Weighted cumulative ISR was 97.25% in 70 implants. A meta-analysis was not possible due to the lack of studies with an eligible control group. Therefore, the data should be interpreted with caution.

CONCLUSION

Less marginal bone loss and more predictable soft tissue parameters can be achieved for immediately restored implants with simultaneous peri-implant gap filling compared with gap with dehiscence/fenestration grafting. Increased ISR for implants with gap filling was observed. However, more evidence is needed to confirm whether immediate provisional prostheses should be utilized when bone defects are simultaneously augmented around the implants.

Critical review on bone grafting during immediate implant placement

In the last 20 years, immediate implant placement has been proposed as a predictable protocol to replace failing teeth. The research conducted in preclinical and clinical studies have focused on soft and hard tissue changes following tooth extraction and immediate implant placement. Different approaches for hard and soft tissue grafting together with provisional restorations have been proposed to compensate tissue alterations. This review analyzed some relevant clinical and preclinical literature focusing on the impact of bone grafting procedures on immediate implant placement in terms of hard and soft tissue changes, aesthetic results, and patient-related outcomes.

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.

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.

Bone dimensional changes after flapless immediate implant placement with and without bone grafting: Randomized clinical trial

INTRODUCTION

Immediate implant in postextraction sockets requires managing the postextraction alveolar resorption. This randomized clinical trial examined vertical and horizontal changes 1-year following flapless immediate implant with and without xenograft at sites with thin labial plate.

METHODS

Forty patients with hopeless teeth in maxillary esthetic zone were randomly assigned to receiving either one immediate implant without bone graft (control) or with bone graft (intervention). Cone beam computed tomography (CBCT) scans were obtained pre-extraction and 1-year postoperatively to measure thickness and dimensional changes of the labial bone.

RESULTS

Cone beam computed tomography measurements revealed that a xenograft, when compared to no xenograft, led to 0.2 mm increased fill of the horizontal gap (95% confidence interval (CI): -1.1, 0.7). In both groups, there was a significant reduction in the labio-palatal bone width after 1 year compared to baseline (P ≤ 0.05). There was no significant difference (P > 0.05) between the xenograft when compared to no xenograft regarding the labio-palatal bone collapse % at 0 mm (-0.2, 95% CI: -4.8, 4.5) and 2 mm apical to the labial crest (1.9, 95% CI: -1.8, 5.6). While at 5 mm the ridge was significantly reduced (P ≤ 0.05) in the no xenograft when compared to xenograft (4.5, 95% CI: 0.7, 8.2). The xenograft when compared to no xenograft, led to 1.1 mm less vertical bone changes (95% CI: 0.4, 1.9). Both groups revealed significant positive correlation between labio-palatal socket dimension and bone formed labial to the implant (P ≤ 0.05). [Correction added on 7 February 2023, after first online publication: In the 8th line of this section, the word "collapse" was changed to "ridge" in this version.] CONCLUSION: This investigation suggested that immediate implants with or without grafting the labial gap preserved alveolar bone dimension and that bone formation labial to the implant was related to initial labio-palatal socket dimension.

Esthetic complications in implant dentistry

Esthetic complications in implant dentistry have become a significant consideration for patients and practitioners. This review presents an appraisal on the current knowledge of the physiological peri-implant soft-tissue dimensions and factors that may compromise peri-implant tissue esthetics. Factors such as papilla fill adjacent to the implant and midfacial mucosal height are critical parameters that determine the esthetic success of implant-supported restorations. Papilla fill adjacent to a single dental implant appears to depend upon the clinical attachment level of the neighboring tooth. A horizontal inter-implant distance of at least 3 mm is necessary to ensure optimal interproximal mucosal embrasure between two adjacent implants in the anterior maxilla. In cases where implants cannot be placed at least 3 mm apart, a single implant with a cantilever bridge should be considered. Buccolingual implant positioning plays a major role in midfacial mucosal height. Soft-tissue volume grafting following immediate implant placement in the presence of a thin soft-tissue phenotype or simultaneous to surgical peri-implantitis therapy might help to overcome facial mucosa recession.

Clinical evaluation of 3D printed nano-porous hydroxyapatite bone graft for alveolar ridge preservation: A randomized controlled trial

Background/purpose

Ridge resorption after tooth extraction may result in inadequate bone volume and unfavorable ridge architecture for ideal implant placement. The use of bone substitutes has been advocated to fill extraction sites and to enhance primary implant stability. This study was made to evaluate the clinical efficacy of novel 3D printed nano-porous hydroxyapatite (3DP HA, test group) in comparison to nano-crystalline bone graft (NanoBone®, control group) in alveolar ridge preservation prior to implant placement.

Materials and methods

Thirty patients were randomized into two groups following tooth extraction. All extracted sockets were filled with 3DP HA or NanoBone® and covered with a non-resorbable membrane. After four months, cone-beam computed tomography (CBCT) and intraoral scanner were used to measure dimensional changes of bone and soft tissue surface. Bone core specimens were harvested for histological analysis during implant osteotomy. Implant stability was assessed using a modified damping capacity analysis.

Results

At four months postoperatively, dimensional changes in soft tissue surface resorption were less in the test group than in the control group; however, alveolar bone resorption was the same in both groups. Histological analysis revealed new bone formation, residual graft and fibrous connective tissue in both groups. The average primary implant stability (IST) value for both groups was approximately 70. There was no statistically significant difference in all parameters between two groups (p > 0.05).

Conclusion

3DP HA could potentially be used as an alternative bone graft material for alveolar ridge preservation.

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.

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).

Optimizing autologous bone contribution to implant osseointegration

BACKGROUND

Autologous bone can be harvested from the flutes of a conventional drill or from a bone scraper; here we compared whether autologous bone chips generated by a new slow-speed instrument were more osteogenic than the bone chips generated by conventional drills or bone scrapers. Additionally, we tested whether the osteogenic potential of bone chips could be further improved by exposure to a Wnt signaling (WNT) therapeutic.

METHODS

Osteotomies were prepared in fresh rat maxillary first molar extraction sockets using a conventional drill or a new osseo-shaping instrument; titanium alloy implants were placed immediately thereafter. Using molecular/cellular and histologic analyses, the fates of the resulting bone chips were analyzed. To test whether increasing WNT signaling improved osteogenesis in an immediate post-extraction implant environment, a WNT therapeutic was introduced at the time of implant placement.

RESULTS

Bone collected from a conventional drill exhibited extensive apoptosis; in contrast, bone generated by the new instrument remained in situ, which preserved their viability. Also preserved was the viability of the osteoprogenitor cells attached to the bone chips. Exogenous treatment with a WNT therapeutic increased the rate of osteogenesis around immediate post-extraction implants.

CONCLUSIONS

Compared with conventional drills or bone scrapers, a new cutting instrument enabled concomitant site preparation with autologous bone chip collection. Histology/histomorphometric analyses revealed that the bone chips generated by this new tool were more osteogenic and could be further enhanced by exposure to a WNT therapeutic. Even though gaps still existed in placebo controls and liposomal WNT3A (L-WNT3A) cases, the area of peri-implant bone was significantly greater in L-WNT3A treated sites.

Validity of a regenerative procedure for a minor bone defect with immediate implant placement: a systematic review and meta-analysis

OBJECTIVE

This systematic review evaluates implant survival and the change in the width of the horizontal ridge following immediate implant placement with or without a regenerative procedure.

MATERIALS AND METHODS

An electronic search of MEDLINE, EMBASE, and the LILACS database of the Cochrane Central Register of controlled trials was performed, along with a manual search, up to April 2018. Randomized controlled trials (RCTs) and quasi-randomized controlled clinical trials (CCTs) with >10 subjects were eligible for this systematic review. A meta-analysis of the risk difference in implant failure between the regenerative and non-regenerative procedure groups was performed using a fixed-effect model. In addition, a meta-analysis of the change in alveolar bone width was conducted using a fixed-effect model.

RESULTS

Seven studies (six RCTs and one CCT) were included. A meta-analysis of three studies found no statistically significant risk difference in implant failure between the regenerative procedure and non-regenerative procedure groups. A meta-analysis of four studies showed that horizontal shrinkage of the alveolar ridge in the site of immediate implant placement was statistically significantly lower with the regenerative procedure than without it (<1 year follow up studies: weighted mean difference (WMD) 0.75 mm, 95% confidence interval 0.41-1.09, p < .00001; ≥1 year follow up study: WMD 1.22, 95% confidence interval 0.52-1.91, p = .00006; total: WMD 0.84 mm, 95% confidence interval 0.53-1.14, p < .00001).

CONCLUSION

Within the study limitations, immediate implant placement with a regenerative procedure showed similar implant survival and less shrinkage of the ridge width than immediate implant placement without a regenerative procedure. Due to the high risk of bias and small sample sizes of the included studies, further clinical studies are warranted to draw definitive conclusions.

Effect of guided bone regeneration on immediately placed implants: Meta-analyses with at least 12 months follow up after functional loading

INTRODUCTION

Immediate implant placement (IIP) into fresh extraction socket is a favorable treatment option. If successfully managed, it reduces the overall treatment time, and increases patient's satisfaction. Surgical and restorative factors affect IIP success rates. In this systematic review we evaluate the effect of guided bone regeneration (GBR) at the time of IIP on crestal bone level (CBL) changes after at least 12-months of functional loading.

METHODS

Reviewers conducted an independent search of the National Center for Biotechnology Information PubMed, Medline, and the Cochrane Collaboration Library from 1966 to January 2017 following the inclusion criteria. A hand search of bibliographies of reviews and clinical trials related to IIP was also performed. This study looked into CBL changes around IIP primarily and further extracted the data to conduct three meta-analysis of "IIP using GBR versus IIP without GBR", "IIP using bone graft alone versus IIP using bone graft with membrane" and "IIP using GBR versus conventional implant placement" which were further subdivided to provide more detailed information for each. Four reviewers independently assessed the study data and methodologic quality using data extraction and assessment forms.

RESULTS

The electronic search identified 714 potential studies and the hand search retrieved 55 studies. Crestal bone level (CBL) changes were determined in three meta-analyses. The results revealed a mean difference in CBL changes of 0.179 ± 0.174 mm  in favor of IIP without GBR when compared with implant with GBR. However, IIP with bone graft and membrane showed better results when compared with IIP with bone graft alone [CBL changes of 0.532 ± 0.572 mm]. CBL preservation was noted in IIP with GBR versus conventional implant placement [CBL changes of - 0.001 ± 0.049 mm].

CONCLUSIONS

Meta-analyses showed minimal difference in CBL around IIP with bone graft versus without bone graft and with IIP with GBR compared with conventional implant placement. However, IIP with bone graft and membrane reported better CBL preservation compared with IIP with bone graft alone. Nonetheless, these results should be interpreted with caution because of moderate heterogeneity between studies.

The influence of bone graft procedures on primary stability and bone change of implants placed in fresh extraction sockets

Background

This study was to evaluate the effect of bone graft procedure on the primary stability of implants installed in fresh sockets and assess the vertical alteration of peri-implant bone radiographically.

Methods

Twenty-three implants were inserted in 18 patients immediately after tooth extraction. The horizontal gap between the implant and bony walls of the extraction socket was grafted with xenografts. The implant stability before and after graft procedure was measured by Osstell Mentor as implant stability quotient before bone graft (ISQ bbg) and implant stability quotient after bone graft (ISQ abg). Peri-apical radiographs were taken to measure peri-implant bone change immediately after implant surgery and 12 months after implant placement. Data were analyzed by independent t test; the relationships between stability parameters (insertion torque value (ITV), ISQ abg, and ISQ bbg) and peri-implant bone changes were analyzed according to Pearson correlation coefficients.

Results

The increase of ISQ in low primary stability group (LPSG) was 6.87 ± 3.62, which was significantly higher than the increase in high primary stability group (HPSG). A significant correlation between ITV and ISQ bbg (R = 0.606, P = 0.002) was found; however, age and peri-implant bone change were not found significantly related to implant stability parameters. It was presented that there were no significant peri-implant bone changes at 1 year after bone graft surgery.

Conclusions

Bone graft procedure is beneficial for increasing the primary stability of immediately placed implants, especially when the ISQ of implants is below 65 and that bone grafts have some effects on peri-implant bone maintenance.

Soft Tissue Changes Around Immediately Placed Implants: A Systematic Review and Meta-Analyses With at Least 12 Months of Follow-Up After Functional Loading

BACKGROUND

Immediate implant placement (IIP) is predictable but can lead to esthetic challenges, including midfacial recession (MFR) and papillary height (PH) loss. The aim of this systematic review is to examine the effect of IIP on MFR and PH after at least 12 months of functional loading.

METHODS

Literature review of the Cochrane and MEDLINE electronic databases and hand search up to January 2016 identified eligible studies. Four reviewers independently assessed data quality and methodology.

RESULTS

A total of 106 articles satisfied the inclusion criteria. Twelve studies qualified for three meta-analyses. MFR was slightly less in conventional implant placement (CIP) than in IIP, but the result was not statistically significant (mean difference [MD] -0.064 mm; P = 0.687). Similarly, there was better PH maintenance in CIPs, with statistical significance for distal PH (DPH) only (cumulative PH: MD -0.396, P = 0.010; DPH: MD -0.765, P <0.001; mesial PH [MPH]: MD -0.285, P = 0.256). MFR was slightly less in IIP with thick versus thin biotypes, but not statistically significantly different (MD -0.373, P = 0.243). Pooled data showed statistically significantly less MFR and better PH maintenance in IIP with thick biotype (MFR: MD -0.478, P <0.001; cumulative PH: MD -0.287, P <0.001; MPH: MD -0.288, P <0.001; DPH: MD -0.310, P <0.001). Non-significantly less MFR (MD 0.253, P = 0.384) and significantly better PH maintenance were found in IIP with immediate provisionalization versus conventional restoration (MD -0.519, P = 0.028).

CONCLUSIONS

IIP in thick biotype and with immediate provisionalization had less MFR and better PH than IIP in thin biotype or with delayed restoration. However, these findings should be interpreted with caution due to high heterogeneity, which was calculated using comprehensive meta-analysis statistical software that took into account sample size and different treatment groups, and limited qualified studies.

Clinical and histological evaluation of socket grafting using different types of bone substitute in adult patients

PURPOSE

This clinical and histological study evaluated the healing of extraction sockets after implantation of a biphasic calcium sulfate (CS) alone or in combination with a gamma-radiated human mineralized allograft.

MATERIALS AND METHODS

Ten healthy adult patients participated in the study. A minimum of 2 teeth, per patient, extracted for different reasons were evaluated. Each socket was randomly filled to the crest with either (a) a biphasic CS or (b) large particulate gamma-radiated human mineralized allograft in combination with a biphasic CS.

RESULTS

No complications during reentry of the socket site during bone core retrieval, such as inflammation/immunogenic response, were observed. Histological findings showed a mean new bone (NB) of 33% for sockets filled with biphasic CS and 31% for sockets filled with biphasic CS in combination with allograft material. There was no statistically significant difference in the percentage of NB and the presence of soft tissue between graft materials.

CONCLUSION

Biphasic CS used alone or in combination with an allograft resulted in the same amount of NB formation in alveolar ridge preservation procedures.

Alterations of the bone dimension following immediate implant placement into extraction socket: systematic review and meta-analysis

AIM

This systematic review was aimed at analysing bone dimensional alterations within the first year following immediate implant placement.

MATERIALS AND METHODS

The electronic search was conducted using MEDLINE (PubMed), Cochrane Central Register of Controlled Trials (CENTRAL) and EMBASE from January 1980 to October 2013. Quality assessment of selected articles was performed using Cochrane Collaboration's tool or Newcastle-Ottawa scale according to the design of each study. A meta-analysis was performed to estimate bone dimensional reduction. Weighted mean differences in bone dimension between baseline and follow-up measurement were calculated. Subgroup analysis and mete-regression were conducted to evaluate the effects of different variables.

RESULTS

A total of 1348 articles were identified following the search process. Six studies were included in the present review. The weighted mean buccal horizontal bone dimensional reduction (BHDr) was 1.07 mm and buccal vertical bone dimensional reduction (BVDr) was 0.78 mm. The weighted mean palatal bone dimensional reduction was 0.62 mm horizontally (PHDr) and 0.50 mm vertically (PVDr). The initial thickness of the buccal alveolar plate (TB) of the socket was the only variable significantly correlated with BHDr and BVDr in meta-regression analysis.

CONCLUSIONS

The bone dimensions of immediate implant sites demonstrated approximately 0.5-1.0 mm reduction in vertical and horizontal aspects 4-12 months following surgery. The results should be interpreted with care because of the data heterogeneity. The correlation of the socket buccal wall thickness, and other variables, with dimensional changes of the bony ridge should be investigated further in controlled clinical trials.

A randomized controlled clinical trial to evaluate a new xenograft for alveolar socket preservation

OBJECTIVE

The aim of this clinical trial was to compare the effect of Bio-Oss(®) and a new bovine xenograft (Osseus(®) ) in alveolar sockets after a 24-week healing period.

MATERIALS AND METHODS

A total of 20 adult volunteers ages 30-60 were subjected to single tooth extraction. A tooth extraction was performed at the baseline. All sites were randomly allocated to two test groups (TG1: grafted using a new bovine xenograft, Osseus(®) , and TG2: grafted using commercially available bovine xenograft-Bio-Oss(®) ). Six months later, a sample of the grafted area was obtained and implants were inserted in the same site. Histological sections were examined focusing on the presence of fibrous connective tissue (CT), and newly formed bone in direct contact with the graft. The HE-stained sections were subjected to histomorphometrical evaluation using Image Pro-Plus(®) software (Release 7.0). The definitive crown was placed 3 months later.

RESULTS

Upon completion of the study, no patients were removed from the study and all inserted implants (10 in each group) were eventually integrated. After 6 months, in the TG1, the mean value of new bone formation was 33.7 (± 7.1), for CT was 32.3 (± 8.9) and for the remaining biomaterial was 10.7 (± 16.2). In the TG2, the mean value of new bone formation was 19.3 (± 22.6), of the CT was 49.9 (± 14.1) and of the remaining biomaterial was 22.6 (± 7.9).

CONCLUSIONS

No statistically significant difference was observed between TG1 and TG2 after 6 months (P > 0.05), and both biomaterials afforded a more favorable implant position.