JOMI Clinical Pearls: Soft Tissue Response in Posterior Teeth Adjacent to Interdental Single Implants
By Dr. José Antonio García M.
JOMI Clinical Pearls is a regular column in Perio-Implant Advisory that discusses articles from The International Journal of Oral and Maxillofacial Implants (JOMI) — the official journal of the AO — as reviewed by a member of the Academy’s Young Clinicians Committee (YCC). Quintessence Publishing publishes JOMI. Today’s study is pulled from Volume 31, Number 3, 2016.
The aim of this randomized controlled clinical trial (RCT) was to evaluate the soft tissue response in posterior teeth adjacent to interdental single implants placed using intrasulcular or trapezoidal incision, and to analyze soft tissue changes over time. The null hypothesis was that the incision type in implant surgery does not have any effect on soft tissue response.
All patients received an interdental single implant. The incision type was randomized by sealed envelopes into two groups: (1) intrasulcular or (2) trapezoidal incision. Forty patients with one implant per patient were included: 20 in each group.
Probing depth and gingival recession at the mesial and distal teeth adjacent to the implant were measured before implant placement, 1 month after surgery, the day of the abutment connection, and at 6 months and 1 year postloading. Scar formation and papilla index were measured 1 month after surgery, and at 6 months and 1 year postloading.
All implants were placed using the same surgical protocol under local anesthesia.
Group A, intrasulcular incision: A crestal incision was performed in the attached mucosa of the edentulous area, including the sulcus of the adjacent teeth, without release incisions (Figs 1a and 1b).
Group B, trapezoidal incision: A crestal incision was performed in the attached mucosa of the edentulous area without reaching the interproximal soft tissue surrounding adjacent teeth and making two release incisions. The distance from the midcrestal incision to the interproximal aspect of the adjacent teeth was approximately 1.5 to 2 mm (Figs 2a and 2b).
Perioperative antibiotic prophylaxis was initiated 2 hours prior to surgery and maintained for 3 days postsurgery. Patients were prescribed ibuprofen 600 mg tablets, when necessary, and were instructed to rinse with 0.12% chlorhexidine digluconate for 1 minute, twice a day for 2 weeks. No provisionalization was performed. It was considered that this may influence periodontal parameters and that it was not necessary since cases belonged to the posterior region. Sutures were removed 1 week after surgery. After a healing period of 12 weeks, single-tooth screw-retained porcelain restorations were loaded.
Patients were followed for a period of 1 year after prosthetic rehabilitation. Because bacteria or their products may cause chronic inflammation, patients received professional oral hygiene every 3 months to prevent eventual bias caused by differing hygiene levels.
The following parameters were assessed before implant placement, 1 month after surgery, the day of the abutment connection, and at 6 months and 1 year after implant loading:
- Probing depth (PD)
The following parameters were also measured at 1 month, 6 months, and 1 year after surgery:
- Scar formation: Digital clinical photographs were used to evaluate the scar formation. Scars were classified from more to less esthetic with the following grades: (0) no visible scar, (1) partially visible scar, and (2) clearly visible scar. This variable was only evaluated in the trapezoidal incision group.
- Papilla index (PI): Scores from 0 to 4 were assigned depending on the degree of papilla filling the embrasure (absent, < 50%, > 50%, complete and overgrowth, respectively).
All surgical interventions and postoperative healing periods elapsed without any serious complications or side effects. On the first postoperative day, some patients reported moderate swelling without pain. After 1 week, no inflammation was detectable.
Significant reductions in scar formation were observed over time with the trapezoidal incision both in mesial and distal release incisions. There were significant differences in scar formation between dental arches in mesial teeth.
The purpose of this prospective study was to compare changes in periodontal clinical parameters of teeth adjacent to interdental single implants, placed using two incision types. The results of the present investigation demonstrated that major soft tissue changes around teeth adjacent to single implants take place between abutment connection and 1 year postloading. Better papilla scores were obtained with trapezoidal than with intrasulcular incision.
A higher mean recession value was observed with the trapezoidal than with the intrasulcular incision, not reaching statistical significance. The trapezoidal incision can severely impair the vascular supply, and scar formation and gingiva shrinkage are possible complications. Significant reductions in scar formation were observed over time with the trapezoidal incision both in mesial and distal release incisions.
Considering the whole sample, the values between implant placement and 1 year postloading showed significant differences in recession, scar formation, and papilla index over time.
Conclusion: The incision type used to place a single interdental implant did not significantly influence the periodontal parameters of the adjacent teeth. Both intrasulcular and trapezoidal incisions may be considered predictable options.
Fig 1a - Picture representing the buccal view of the intrasulcular incision
Fig 1b - Occlusal view of the intrasulcular incision
Fig 2a - Picture representing the buccal view of the trapezoidal incision
Fig 2b - Occlusal view of the trapezoid incision
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