International Journal of Periodontics & Restorative Dentistry, 04/2022

Recently, the Low Window technique was proposed to facilitate sinus augmentation and reduce postsurgical patient discomfort. It was shown to be both safe and effective. This case series evaluates the postsurgical discomfort of patients undergoing Low Window sinus augmentation, the bone gain achieved, and whether these factors correlate with the osteotomy area. Records of patients (n = 26) who underwent a sinus elevation using the Low Window approach (n = 34 interventions), followed by implant placement and prosthetic rehabilitation (n = 97 implants), were assessed retrospectively. The analyzed outcomes were the medial, middle, and lateral bone gain ≥ 9 months after augmentation; pain at 5 to 6 hours postsurgery, evaluated on a visual analog scale (VAS; 0 to 100); pain, swelling, and hematoma formation every day up to 7 days postsurgery, evaluated by VAS; implant and prosthetic success and survival rates; and rate of complications. The average follow-up time was 62.1 ± 14.9 months. No intraoperative sinus membrane perforations or other complications occurred. Medial, middle, and lateral bone gains were 10.1 ± 1.7 mm, 11.6 ± 0.8 mm, and 10.7 ± 0.9 mm, respectively. At the last follow-up, the implant success rate was 99%. Postsurgical VAS pain 5 to 6 hours postsurgery was 12.3 ± 8.0 and decreased significantly thereafter. Swelling prevalence was 29.4% at 1 day postsurgery, 20.6% at 2 days, and 2.9% the following day. No swelling was observed from day 4 onward. Prevalence of hematoma was 8.8% for 2 days postsurgery, 2.9% the day after, and no hematoma was observed thereafter. Only the osteotomy area correlated with immediate postsurgical pain, but not with other discomfort outcomes or with bone gain. Low Window sinus elevation might allow bone gain and medium-term implant and prosthetic success rates similar to that of other access window designs. Prospective, comparative studies are needed to investigate whether the technique is more advantageous than traditional approaches.

This study evaluates the fatigue resistance and failure mode of CAD/CAM composite resin and lithium disilicate-bonded screw-retained incisor crowns with long and short titanium bases. Sixty CAD/CAM implant restorations were fabricated using lithium disilicate (IPS e.max CAD, Ivoclar Vivadent) and composite resin (Block HC, Shofu). The central incisor crowns were bonded to a prefabricated titanium base 6 mm tall (groups: Emax6 and Shofu6; n = 15 each) or a modified abutment 4 mm tall (groups: Emax4 and Shofu4; n = 15 each). The intaglio surface of the restorations was conditioned according to the material and bonded to the titanium abutments/bases using dual-cure cement. All assembled crowns were torqued onto implants and subjected to cyclic isometric loading at the incisal edge along the implant axis. Samples were loaded until fracture. Groups were compared using Kaplan-Meier survival analysis (log rank test at P = .05). The number of mean survived cycles differed significantly, with Emax6 and Emax4 at 48,448 and 43,727 cycles, respectively, and Shofu6 and Shofu4 at 44,124 and 37,620 cycles, respectively. Post hoc tests showed similar fatigue resistance for Emax6, Emax4, and Shofu6. Shofu4 was less resistant than all other groups (P < .03). All restorations survived significantly above physiologic load limits. Lithium disilicate screw-retained incisor crowns can be used with long and short titanium bases, while it is recommended to keep a long titanium base for screw-retained composite resin crowns. The composite resin material required the full height of the abutment for optimal strength but may offer enhanced shock absorption and wear-friendliness when considering function and antagonistic wear.

Common challenges encountered for atrophic maxilla rehabilitation are the inadequate width and height of attached keratinized mucosa (AKM) and shallow vestibular depth. This study presents a buccally displaced palatal (BDP) flap technique to increase the tissue thickness and AKM width at the second-stage surgery and reestablish the correct fornix depth. The peri-implant pocket depths, modified Plaque Index score, modified sulcus Bleeding Index score, and soft tissue recession were evaluated 6 and 12 months after prostheses loading. A total of 52 implants were placed and analyzed, and no implant failures were found. No significant changes in peri-implant parameters were observed between 6 and 12 months, and mean recession was less than 0.2 mm after 12 months. Though this change was statistically significant, it was clinically irrelevant. The results demonstrate that adequately healthy peri-implant soft tissues and substantial dimensional stability of vestibular soft tissues at the 1-year follow-up were achieved with the BDP flap technique. The BDP flap could represent a viable option for increasing the width and the height of AKM and establishing the correct maxillary fornix depth.

This ex vivo study evaluates the incidence of sinus membrane perforation during implant site osteotomy with two different types of drills and drilling techniques. Fifty goat heads with 50 sinus pairs (100 sinus sides) were assigned to two groups (osseodensification bur [OB] group and inverse conical shape bur [ICSB] group) to simulate transcrestal sinus elevation (50 sinus sides per group). An osteotomy was performed to pass through the lateral sinus wall no more than 3 mm. The integrity of the sinus membranes was examined and confirmed under a microscope. Of the 50 sinuses per group, the OB group presented with 14 (28%) perforated sinuses, while the ICSB group presented with 2 (4%) perforated sinuses. Of the 14 perforations from the OB group, 6 (42.9%) showed a pinpoint perforation pattern, 4 (28.5%) of which were not visible until direct air pressure was applied. Overall, the ICSB drill group demonstrated a lower sinus perforation rate than the OB group.

This study evaluated the radiographic alterations that occur in immediate postextraction implants and in delayed implants inserted in a preserved ridge. In group A, an implant was placed immediately after tooth extraction, grafting the bone-to-implant gap. In group B, alveolar ridge preservation was performed after tooth extraction, and delayed implant placement was performed 4 months later. The final follow-up was 1 year after prosthetic loading in both groups. The marginal bone level (MBL) was measured at implant insertion (T1), at loading (T2), and at the final follow-up, 12 months after prosthetic loading (T3). At tooth extraction (T0) and T3, the horizontal ridge width (HW) was measured on CBCT scans at three different levels. No statistically significant differences in MBL or HW were found between the two study groups. The outcomes suggest that it is possible to maintain MBL and alveolar bone volumes regardless of whether the procedure is performed through immediate postextraction implant placement or through delayed implant placement in a preserved ridge.

This study clinically and histologically evaluated the new bone formation and soft tissue changes when an autogenous tooth-derived mineralized dentin matrix (DDM) graft covered with a free gingival graft (FGG) was used for alveolar ridge preservation, as compared to spontaneous healing. Using a split-mouth protocol, 14 consecutive patients who required two extractions of a single-rooted tooth in the maxillary arch were enrolled. In each patient, one extraction site was treated with DDM and FGG (test group), while the other extraction site was covered with FGG and healed spontaneously (control group). In both test and control sites, implant placement was performed after a 16-week healing period. Compared to baseline (immediately after tooth extraction), both treatments yielded statistically significant differences in some clinical parameters and in the bone micro-architecture within the augmented sites. However, the use of DDM with the FGG created greater new vital bone formation, more newly formed bone, and fewer dimensional tissue changes than spontaneous healing with FGG.

The Modified Minimally Invasive Surgical Technique (M-MIST) was designed to improve wound stability and reduce patient morbidity. This case series aimed to evaluate clinical outcomes of periodontal regenerative therapy using recombinant human fibroblast growth factor (rhFGF)-2 with M-MIST for the treatment of intrabony defects. Following initial periodontal therapy, nine intrabony defects in seven patients received rhFGF-2 therapy. Using M-MIST, a buccal incision was made to gain access to the defect without interdental and lingual incisions. After debridement, rhFGF-2 was applied to the defect. Periodontal parameters were evaluated at baseline and at 3, 6, and 12 months postoperatively. Composite Outcome Measure (COM) and patient-reported outcome measure (PROM, recorded using an oral health-related quality of life [QoL] instrument) were also used for evaluation. At 12 months postoperative, mean probing depth reduction was 4.2 ± 0.8 mm and clinical attachment gain was 4.7 ± 0.7 mm. The mean value for gingival recession was -0.3 ± 0.5 mm. According to COM, the outcomes of the treated sites were successful. An improvement in oral health-related QoL was noted at 12 months compared to after the initial periodontal therapy. This case series shows that rhFGF-2 therapy with M-MIST yields favorable clinical outcomes in the treatment of intrabony defects.

The objective of this study was to assess volumetric and linear changes of buccal mucosal thickness at implant sites following soft tissue augmentation with a volume-stable collagen matrix (VCMX). Soft tissue augmentation using a VCMX was performed in 12 patients at the time of implant placement. Hydrocolloid impressions were taken prior to surgery and at 1 and 6 months postsurgery. Stone cast models were scanned, and stereolithography (STL) files from the three time points were uploaded to an image-analysis software. At all time points, linear and volumetric measurements of the contour changes up to 3 mm apical to the mucosal margin were performed and were analyzed statistically. At 1 mm apical to the mucosal margin, the change in soft tissue thickness between presurgery (T1) and 1 month (T2) amounted to 0.21 ± 1.22 mm, and the change between T1 and 6 months (T3) was 0.08 ± 1.47 mm. At 3 mm apical to the mucosal margin, the change in soft tissue thickness was 1.92 ± 1.70 mm between T1 and T2 and 0.31 ± 1.26 mm between T1 and T3. Contour (volumetric) changes revealed an increase of 0.58 ± 0.73 mm between T1 and T2 and an overall gain of 0.55 ± 0.73 mm between T1 and T3. Soft tissue augmentation with VCMX increased the ridge profile. The increase in ridge width was greater at 3 mm below the ridge crest than at 1 mm below the ridge crest. Remodeling processes during healing showed a decrease in the ridge contour between 1 and 6 months.

Compared to other areas of the oral cavity, an edentulous posterior maxilla poses a unique challenge for implant placement. The most important aspect to consider is the maxillary sinus. This paper describes a case in which the bone ring technique was used to raise the floor of the maxillary sinus, followed by immediate implantation. A 37-year-old woman presented with a ridge defect in the left maxilla and the absence of teeth 26 and 27 (FDI tooth-numbering system) on the same side. The treatment plan involved the extraction of tooth 25, periodontal regeneration on the distal face of tooth 24, and concomitant raising of the maxillary sinus (using the bone ring technique) with simultaneous implantation. The bone ring technique promotes bone augmentation, raises the maxillary sinus, and reduces the surgical time, surgical costs, and length of the rehabilitation period. In the case presented herein, bone tissue stability around the implants, ridge maintenance, and gingival margin stability were found at the 1-year follow-up after rehabilitation.

This study clinically and histologically evaluated the performance of implants with different crestal morphologies: tissue-level implants and bone-level implants. Nine patients received at least two adjacent implants in an edentulous area: one bone-level implant (EO) and one tissue-level implant (TG) (total: 23 implants), placed beside each other using a single-stage delayed loading protocol. The implants were rehabilitated with screw-retained fixed partial dentures. Plaque Index (PI), bleeding on probing (BOP), probing depth (PD), and peri-implant bone level were recorded at various postsurgical follow-ups, including 2 and 6 months as well as 1 and 4 years. At 3 months postsurgery, soft tissue biopsy samples were taken from all implant sites and histologically analyzed. Longitudinal assessment of the results (TG vs EO implants) was performed using a linear mixed model with random intercept and by using Spearman correlation or chi-square after visual inspection of the probability distribution. Student t test was used to compare means, and chi-square test was used for dichotomic variables. P < .05 was considered statistically significant. All implants were functional at 4 years. Peri-implant bone resorption was limited, with means of 1.20 ± 0.71 mm and 1.24 ± 0.82 mm for TG and EO implants, respectively. No significant differences in clinical parameters were identified between EO and TG implants. Histologic analysis revealed normal peri-implant soft tissue healing with poor inflammatory infiltrate. Differences in the histologic appearance of soft tissues were more related to patients than implant type. Both implants appeared to be suitable for partial rehabilitation of edentulous arches without differences in the investigated clinical and histologic parameters. However, TG implants showed a greater risk of implant collar exposure.

Tissue volume loss after tooth extraction is an esthetic challenge. The socket-shield technique (SST) has been used to compensate it with promising results but limited evidence. This prospective study aims to present the dimensional changes after SST. Ten consecutive patients with an anterior hopeless tooth to be extracted and an immediate implant placed using the SST were prospectively enrolled. An impression and a CBCT scan were taken prior to surgery and 6 months later. Models were scanned, and DICOM and STL (standard tessellation language) files were superimposed and analyzed by software to measure the dimensional differences. Five patients could be evaluated for bone alterations and 9 for soft tissue alterations. The mean horizontal shrinkage of the buccal bone plate at 1 mm from the most coronal part was -0.22 ± 0.13 mm in the CBCT analysis. The mean volume loss in the region of interest was -2.94 ± 2.45 mm³, with a mean change in soft tissue contours of -0.49 ± 0.41 mm between pre- and postoperative analysis. SST limited the buccal contour loss after tooth extraction and may be considered a potential option to prevent volume loss in immediate implant placement. Further standardization in the digital measurement method is still needed.

The aim of this randomized prospective study was to compare clinical and patient-centered outcomes of Miller Class I and II gingival recession defects treated with acellular dermal matrix (ADM) grafts and either vestibular incision subperiosteal tunneling access (VISTA) or sulcular tunnel access (STA) techniques. A total of 29 gingival recession defects in nine patients were assessed to determine clinical outcomes, including probing depth (PD), gingival recession (GR), width of keratinized tissue (KT), width of attached tissue (AT), tissue thickness at the gingival margin (TT1), and tissue thickness 4 mm apical to the gingival margin (TT2). Visual analog scale (VAS) assessment of patient-perceived pain, bleeding, swelling, and changes in activity were assessed postoperatively at 7 and 30 days, and professional assessment of postoperative esthetics using the Pink Esthetic Score (PES) was performed at 6 months. All sites demonstrated significant improvements in midfacial GR. No statistically significant differences were noted between the VISTA and STA groups for clinical or patient-centered outcomes, except for preferable midfacial AT in the VISTA sites at 6 months. These findings indicate that both surgical techniques can be used with ADM grafts to achieve improvements in root coverage, alterations in periodontal phenotype, and improved esthetics with high levels of patient satisfaction.

The present study introduces a novel "anatomic recession ratio" (ARR) and evaluates the clinical outcomes of using a tunnel technique (TUN) with a connective tissue graft (CTG) for root coverage (RC). Sixteen systemically healthy patients contributing a total of 33 recession types 1 and 2 were treated with TUN + CTG. The predictive value of a panel of baseline clinical parameters (ARR) on RC was evaluated 12 months postoperatively. At 12 months, mean recession depth decreased from 2.74 ± 0.22 mm to 0.46 ± 0.13 mm (P < .0001); 19 sites (58%) showed complete RC, and the mean RC rate was 88.85% ± 2.73%. The mean ARR value was 0.74 ± 0.3, revealing a positive correlation with RC (r²: 0.73, P < .0001). The 12-month esthetic evaluation resulted in a score of 8.52 ± 1.75 using the root coverage esthetic score. TUN + CTG is effective in reducing recession depth and obtaining good esthetic outcomes. Within the limits of the present study, it may be suggested that ARR has potential as an analytical baseline parameter for RC outcomes with TUN + CTG.

This study presents a one-stage technique for horizontal guided bone regeneration and transmucosal implant placement in the presence of hard and soft tissue defects. The proposed technique uses autologous bone particles, deproteinized bovine bone matrix, collagen membranes, and concentrated growth factor membranes to create a multilayer barrier and enhance tissue regeneration. Four patients were treated with a total of seven implants. Digital analyses of intraoral scan data taken at baseline and at 6 months postsurgery showed a mean increase in tissue volume of 157.4 mm³. The patient satisfaction was high, and no complications were observed.