Soft and hard tissue evaluation of guided socket shield implant cases.

BACKGROUND: The socket-shield (SS) technique results in long-term functional osseo- and dento-integration, preserving the dimensional stability of hard and soft tissues over time. This study aimed to describe the successful implementation of a surgical technique to facilitate "SS" cases. METHODS: The cases included males and females aged 32-81 years consecutively treated between 2020 and 2023 (longest follow-up, 3.5 years). For each case, pre- and post-operative cone-beam computed tomography (Digital Imaging and Communications in Medicine files) and intraoral optical scans (IOS; STL files) were performed. Digital immediate implant placement and simultaneous tooth extraction and SS production were planned using an implant planning software. Implants were planned considering sagittal-ridge and tooth-root angular-configuration. Surgical guides were used to perform the digitally-supported SS technique. All cases were planned and surgically performed by one operator (Pedro M. Trejo). Preoperative digital IOS-models were superimposed to post-operative models to assess soft-tissue changes. Pre and post sagittal views were used to assess the radiographic buccal-plate thickness at various healing times. An investigator not involved with case planning or treatment performed measurements. RESULTS: Results reflected soft-tissue stability with minimal mean thickness change at 0-, 1-, 2-, and 3-mm measurement levels of 0.03, -0.2, 0.14, -0.07, and 0.04 mm, respectively, with a mean gingival-margin change of 0.04 mm. The free gingival-margin change ranged from a 0.58-mm gain in height to a -0.57-mm loss. The mean radiographic buccal-plate thickness post-operatively was 2.04 mm (range, 0.7-2.9 mm). CONCLUSION: The digitally-supported guided SS technique enables predictable immediate implant-placement positions and stable buccal peri-implant soft and hard tissues over time. KEY POINTS: Why are these cases new information? The uniqueness of the surgical technique described herein is that it results in favorable positions of immediate, socket-shielded (SSed), implant placements, with soft- and hard-tissue stability as the byproduct. What are the keys to successful management of these cases? Digitally, plan for the best possible implant position within the alveolar housing to satisfy prosthetic requirements, and then adjust this position to accommodate the socket shield dimensions. Digitally, provide a space/gap between the future dentinal shield and the implant. Clinically, allow for time to carve the final position and dimensions of the shield. Plan ahead the extent of the apical third of the SS, and the removal of the apex, if dealing with a long root. What are the primary limitations to success in these cases? Inadequate use of digital technology; case-sensitive technique requires proper execution of each digital and technical clinical step.

The ability to screw-retain single implant-supported restorations in the anterior maxilla: A CBCT analysis.

STATEMENT OF PROBLEM: Evidence to validate the routine use of angled screw-channel abutments in the anterior maxilla is sparse. If properly planned, they might provide surgical and prosthetic benefits. PURPOSE: The purpose of this observational study was to determine the prevalence of digitally placed implants in the anterior maxilla that would allow screw-retained implant-supported restorations with either a straight or an angled screw-channel abutment. MATERIAL AND METHODS: Two hundred cone beam computed tomography (CBCT) scans met the inclusion criteria for retrospective analysis and digital implant planning. Virtual implants were planned for randomly selected anterior maxillary teeth by using the anatomic crown and root position. Virtual abutments of varying angulation were attached to the implants to determine the ability to screw retain a restoration with either a straight or an angled screw-channel abutment. RESULTS: One hundred fifty-two (76%) sites required an angled screw-channel abutment to enable screw retention. Forty-eight (24%) sites allowed screw retention with a straight abutment. The percentage of implants requiring angled or straight abutments varied significantly among anterior teeth (P<.005). One hundred nine (71.7%) angled screw-channel abutment sites required a 5-degree abutment, 41 (26.9%) required a 10-degree abutment, and 2 (1.3%) required a 15-degree abutment. Among the anterior teeth, lateral incisors presented a greater need for angled screw-channel abutments. None of the implants in the present study needed cement-retained restorations. CONCLUSIONS: Angled abutments allowed for screw-retained restorations on digitally planned implants in the anterior maxilla. The required angular correction to a screw-retained restoration was ≤15 degrees. Screw-retained restorations were frequently achievable (76%) with the use of angled screw-channel abutments or with straight abutments (24%), and lateral incisors presented a greater need for angled screw-channel abutments.

Regeneration of degree ii furcation defects with a 4% doxycycline hyclate bioabsorbable barrier.

BACKGROUND: Bacterial contamination of a healing regenerative site has been shown to affect the response to therapy adversely. Doxycycline possesses antibacterial properties as well as other biologic actions that may result in an increased production and maintenance of collagen and bone. The purpose of this study was to assess if the sustained release of 4% doxycycline through a bioabsorbable barrier would enhance the regenerative outcomes of healing furcation sites. METHODS: Individuals with a single degree II furcation defect in a mandibular molar participated. They were assigned randomly to one of three treatment groups: poly(DL-lactide) polylactic acid (PLA) barrier containing 4% doxycycline hyclate + demineralized freeze-dried bone allograft (DFDBA) (BG+PDox); poly(DL-lactide) PLA barrier without doxycycline + DFDBA (BG+P); or DFDBA alone (BG). Clinical parameters included vertical probing depth (VPD), vertical clinical attachment level (VCAL), gingival recession, and horizontal probing depth (HPD). Intrasurgical measurements to calculate vertical and horizontal furcation fill were obtained at the time of surgery (baseline) and during a reentry procedure 9 months later. Statistical tests were used to assess changes in the clinical and surgical parameters before and after treatment among groups and within each group. RESULTS: Mean changes at 9 months for all groups yielded VPD reductions and VCAL gains. However, no significant difference was noted for the group that was treated with 4% doxycycline barrier compared to the other two groups. Vertical bone fill was 0.89, 1.44, and 1.18 mm for the BG+PDox, BG+P, and BG groups, respectively. Furcation horizontal bone was 2.33, 2.11, and 1.18 mm for the BG+PDox, BG+P, and BG groups, respectively. CONCLUSIONS: Addition of doxycycline to the guided tissue regeneration barrier did not enhance treatment outcomes compared to the non-antibiotic-loaded barrier or bone graft alone. All treatment modalities provided similar improvement in clinical and intrasurgical parameters.

Effect of mechanical and antiseptic therapy on peri-implant mucositis: an experimental study in monkeys.

OBJECTIVES: This experiment was performed to evaluate clinically and histologically the effect of mechanical therapy with or without antiseptic therapy on peri-implant mucositis lesions in nine cynomolgus monkeys. MATERIAL AND METHODS: Two ITI titanium implants were inserted into each side of the mandibles. After 90 days of plaque control and soft tissue healing, a baseline clinical examination was completed. Peri-implant lesions were induced by placing silk ligatures and allowing plaque to accumulate for 6 weeks. The clinical examination was then repeated, and the monkeys were randomly assigned to three treatment groups: group A, mechanical cleansing only; group B, mechanical cleansing and local irrigation with 0.12% chlorhexidine (CHX) and application of 0.2% CHX gel; and group C, control, no treatment. The implants in treatment groups A and B were treated and maintained according to the assigned treatment for two additional months. At the end of the maintenance period, a final clinical examination was performed and the animals were sacrificed for biopsies. RESULTS: The mean probing depths (PD) values at mucositis were: 3.5, 3.7, and 3.4 mm, and clinical attachment level (CAL) = 3.8, 4.1, and 3.9 mm for treatment groups A, B and C, respectively. The corresponding values after treatment were: PD = 1.7, 2.1, and 2.5 mm, and CAL=2.6, 2.6, and 3.1 mm. ANOVA of mean changes (Delta) in PD and CAL after treatment showed no statistical difference between the treatment groups. Comparison of the mean changes in PD and CAL after treatment yielded statistical differences between the control and treatment groups P < 0.01. According to the t-test, no statistical difference was found between treatment groups A and B for the PD reduction but there was a significant difference for the CAL change, P < 0.03. Group A had significantly more recession and less CAL gain than group B. Non-parametric tests yielded no significant differences in modified plaque index (mPlI) and gingival index (GI) after treatment between both treatment groups. Frequencies and percent distributions of the mPlI and GI scores changed considerably for both treatment groups when compared with the changes in the control group after treatment. With regard to the histological evaluation, no statistical differences existed between the treatments for any linear measurement. The proportion of inflammation found in the mucosal tissues of the control implants was greater than the one found for both treatment groups, P < 0.01. More importantly, both treatment groups showed a similar low proportion of inflammation after 2 months of treatment. CONCLUSIONS: Within the limitations of this experiment, and considering the supportive plaque control rendered, it can be concluded that for pockets of 3-4 mm: (1) mechanical therapy alone or combined with CHX results in the clinical resolution of peri-implant mucositis lesions, (2) histologically, both treatments result in minimal inflammation compatible with health, and (3) the mechanical effect alone is sufficient to achieve clinical and histologic resolution of mucositis lesions.

Favorable periodontal regenerative outcomes from teeth with presurgical mobility: a retrospective study.

BACKGROUND: The relevance of tooth mobility on periodontal healing is still controversial. The purpose of the present study was to evaluate the effect of presurgical tooth mobility on periodontal regenerative outcomes. METHODS: The data in this study were derived from three randomized clinical trials which evaluated regenerative procedures. Sixty-four patients with one intraosseous periodontal defect each received one of the following treatments: guided tissue regeneration (GTR) using expanded polytetrafluoroethylene (ePTFE), GTR using a bioabsorbable membrane with or without demineralized freeze-dried bone allograft (DFDBA), or enamel matrix derivative with or without DFDBA. Probing depth (PD), clinical attachment level (CAL), recession (REC), and tooth mobility (TM) were recorded at baseline and 1 year after treatment by a calibrated examiner. The post-surgical follow-up and maintenance periods were designed to optimize plaque control. The teeth were grouped according to their baseline Miller index TM score. The grouping yielded 36 teeth with minimal mobility, score 0; 13 teeth with score 1; and 15 with score 2. The mean changes in PD, CAL and REC from baseline to 1 year were calculated for each group. One-way analysis of variance (ANOVA) was performed to assess differences between the tooth mobility groups considering changes in PD, CAL, and REC at 1 year. RESULTS: The mean PD reduction from baseline to 1 year for teeth with TM score 0 was 3.67 mm; for TM score 1, 2.81 mm; and for score 2, 3.73 mm. The corresponding values for the gain in CAL were 2.73, 1.96, and 2.36 mm, respectively. According to ANOVA, the probing depth reductions and clinical attachment level gains found in each group were not statistically different, P= 0.218 and P= 0.252, respectively. CONCLUSION: Within the limitations of this analysis, it can be concluded that interproximal, intraosseous defects of teeth with limited presurgical tooth mobility; i.e., teeth with Miller's Class 1 and 2 mobility, will respond favorably to regenerative therapy.

Treatment of intrabony defects with bovine-derived xenograft alone and in combination with platelet-rich plasma: a randomized clinical trial.

BACKGROUND: In the treatment of periodontal intrabony defects, the benefits of adding platelet-rich plasma (PRP) to a bone replacement grafting material have not been tested. The purpose of this study was to compare the clinical outcomes obtained by the combination of PRP and a bovine derived xenograft (BDX) to those obtained from the use of the bone replacement graft alone. METHODS: Thirteen patients were enrolled in a randomized, split mouth, double-masked clinical trial. Bilateral defects were matched according to their intrasurgical measurements. Qualifying defects had loss of attachment of > or = 6 mm, a radiographically detectable defect of > or = 4 mm, at least two remaining osseous walls, and not primarily related to a furcation involvement. After the hygienic phase, at the baseline examination, probing depth (PD), clinical attachment level (CAL), and recession (REC) were measured. During open flap debridement, the defects were randomly assigned to receive either BDX mixed with PRP or BDX alone. Baseline osseous intrasurgical measurements were obtained. Post-surgical follow-up and maintenance were performed and PD, CAL, and REC were remeasured at 6 months. The mean baseline and 6-month PD, CAL, and REC of the deepest buccal and lingual measurements related to the defect for each group were computed. The change from baseline to 6 months for each parameter measured was calculated. Pre- and postoperative comparisons were made between treatment groups at 6 months. RESULTS: Randomization of the defects resulted in comparable groups (P > or = 0.05). At 6 months, paired t test comparisons within groups showed statistically significant benefits with both treatment modalities (P < or = 0.05). The mean changes (delta) at 6 months for the test and the control groups at the deepest sites were: PD reduction: 3.54 and 2.53 mm; CAL gain: 3.15 and 2.31 mm; and REC: -0.38 and -0.23 mm, respectively. Paired t test comparisons yielded significant differences between treatments for PD and CAL (P < or = 0.05). CONCLUSION: In this 6-month clinical trial, the addition of a high concentration of autologous platelets to a bovine derived xenograft to treat intrabony defects significantly improved their clinical periodontal response.

Clinical response to 2 different therapeutic regimens to treat peri-implant mucositis.

BACKGROUND: Maintenance of implants is imperative, since implants, like teeth, are susceptible to bacterial plaque accumulation and calculus formation, and thus at risk of developing peri-implant mucositis or peri-implantitis. METHODS: This study determined the clinical effects of chlorhexidine treatment on peri-implant mucositis at 1 and 3 months as determined by the modified plaque index, the modified sulcus bleeding index, clinical attachment level, and probing depth. Through DNA probes, the effect of chlorhexidine on the microbial flora of mucositic lesions was also evaluated. The population consisted of 16 adult male and female subjects (ages 34 to 76). After the baseline examination, the subjects received a dental prophylaxis and were randomly assigned to the test or control group. Subjects in the test group received antiseptic therapy (Treatment 1), which included mechanical cleansing and oral hygiene instructions supplemented by the local irrigation with chlorhexidine 0.12%, using a plastic syringe, and the topical application of a 0.12% chlorhexidine gel. The subjects in the control group received only mechanical cleansing and oral hygiene instructions (Treatment 2). RESULTS: Both modalities of treatment were effective in reducing peri-implant mucositis and probing depths, and improving attachment levels. The trends suggested that mechanical cleansing alone may be sufficient to treat and reduce peri-implant mucositis at 1 and 3 months after treatment. The addition of chlorhexidine to mechanical debridement did not enhance the results as compared to mechanical debridement alone. CONCLUSIONS: Mechanical debridement as well as mechanical debridement supplemented with chlorhexidine can be beneficial to patients with peri-implant mucositis. Both treatments resulted in a reduction of plaque, inflammation, and probing depth, as well as a gain in clinical attachment level, and are effective in suppressing or eradicating the pathogenic bacteria often associated with peri-implant inflammation.

Healing after standardized clinical probing of the perlimplant soft tissue seal: a histomorphometric study in dogs.

BACKGROUND/AIMS: Clinical probing of the soft tissues around oral implants has become a frequently used parameter for clinical monitoring. However, the healing of the disruption of the soft tissue seal as a result of probing has not yet been studied. The purpose of this study was to evaluate the healing events in the periimplant mucosal tissues following standardized clinical probing. MATERIALS AND METHODS: In three foxhounds the mandibular premolars were extracted and, after 3 months of healing, TPS screw-shaped implants (ITO Dental Implant System) were installed. A plaque control regimen was performed throughout the duration of the experiment. After 3 months of healing of the transmucosal implants, clinical implant stability and healthy periimplant mucosal tissues with mostly absence of bleeding on probing were obtained. Clinical probing of the mesial and distal implant sites was performed immediately before 1, 2, 3, 5 and 7 days prior to the sacrifice of the animals. A specially manufactured titanium cylinder with a mesial and distal groove was fixed to the implants to standardize the insertion geometry of a pressure-sensitive probe (0.2-0.25 N, tip diameter 0.45 mm). The distances from the alveolar crest to the coronal border of the connective tissue adaptation to the implant and the length of the epithelial attachment were measured histomorphometrically in nondecalcified ground sections. The buccal and lingual aspects of the implants were used to determine the components of the biological width in unprobed control sites. RESULTS: The probe caused a separation between the surface of the implant and the junctional epithelium, but not within the connective tissue adaptation. In general, the probe tip was located at the most coronal level of the supracrestal connective tissue as determined histologically. By 1 day after separation of the periimplant mucosal tissue by probing, an epithelial attachment of approximately 0.5 mm in the apico-coronal direction was observed. The length of the epithelial adaptation showed a tendency to increase over time (day 2: 1.15 mm, day 3: 1.52 mm), and was complete at day 5 (1.92 mm). At the unprobed sites the epithelial attachment showed a mean length of 1.69 mm. Inflammatory infiltrates were practically nonexistent, indicating the absence of tissue trauma or infection as a result of probing. CONCLUSIONS: Clinical probing around osseointegrated implants does not appear to have detrimental effects on the soft tissue seal and, hence, does not seem to jeopardize the longevity of oral implants. The 'healing of the epithelial attachment' seems to be complete 5 days after clinical probing.