Soft Tissue Grafting in Dentistry: Free Gingival Graft, Connective Tissue Graft, and Allograft Options

Why Soft Tissue Matters

Soft tissue grafting is typically performed to solve one or more of four problems: inadequate keratinized tissue, insufficient tissue thickness, gingival recession or marginal instability, and poor soft tissue quality around natural teeth or implants. These deficiencies may create esthetic concerns, but they also create functional and biologic problems. Thin tissue is more vulnerable to recession and show-through. Shallow or non-keratinized tissue can be uncomfortable for the patient to brush. Limited peri-implant soft tissue may be associated with hygiene difficulty, discomfort, and less stable marginal architecture over time. As a result, soft tissue augmentation often improves far more than appearance alone.

This is especially important around implants. Unlike natural teeth, implants lack a periodontal ligament and respond differently to inflammation and restorative contours. For that reason, peri-implant tissue thickness and the presence of an adequate band of keratinized mucosa are often discussed not just in esthetic terms, but in terms of long-term health and maintenance. Systematic reviews suggest that soft tissue augmentation around implants can help maintain the soft tissue margin and marginal bone more favorably over time compared with non-augmented sites.

The Three Main Categories of Soft Tissue Grafting

1. Free Gingival Graft (FGG)

A free gingival graft is an epithelialized graft, usually harvested from the palate, and transferred to a recipient site primarily to increase the width of keratinized tissue. From a biologic and technical standpoint, FGG is one of the oldest and most reliable mucogingival procedures in periodontics. It is not usually selected because it offers the best color blend or the most refined esthetic integration. Instead, it is selected because it predictably creates a stable band of tougher, keratinized tissue where more tissue is needed.

This is why FGG remains highly relevant around mandibular anterior teeth, shallow vestibules, areas with minimal attached gingiva, and peri-implant sites with inadequate keratinized mucosa. If the main problem is not recession coverage but rather a lack of durable keratinized tissue, FGG is often the most straightforward and predictable solution. Recent reviews on soft tissue substitutes and autogenous grafts continue to show that FGG outperforms soft tissue substitutes for increasing keratinized tissue width, especially around implants.

The tradeoff is esthetics and morbidity. Because FGG is epithelialized, the final tissue can appear lighter, denser, or less blended than adjacent tissue. It can also shrink during healing, and the palatal donor site can be uncomfortable. For that reason, FGG is often chosen when function and tissue quality matter more than seamless color match.

2. Connective Tissue Graft (CTG)

Connective tissue grafting is generally regarded as the gold standard soft tissue procedure when the clinical goals include root coverage, soft tissue thickening, contour enhancement, gingival phenotype modification, or peri-implant volume augmentation. CTG is harvested from the palate as subepithelial connective tissue and placed beneath a flap or tunnel, which allows the overlying tissue to maintain a more natural color and surface texture than a traditional FGG.

In practical terms, CTG is the workhorse graft when the clinician wants to improve the quality of tissue without creating the more obvious “patch” effect associated with a free gingival graft. It is widely used for recession coverage, treatment of thin periodontal phenotypes, tissue thickening before or after implant placement, and contour improvement in esthetic areas. The Italian literature has been particularly influential here. Zucchelli and coauthors have repeatedly emphasized that CTG combines high predictability with excellent esthetic integration, which is one reason it remains the benchmark material in periodontal plastic surgery.

CTG is not only about covering exposed roots. It is also about changing phenotype. Reviews on gingival phenotype modification have shown that autogenous CTG-based approaches are among the most effective methods for increasing tissue thickness and improving soft tissue stability over time. Around implants, CTG is often favored when the objective is buccal volume gain, margin stability, or masking of underlying restorative or implant contours in a high-esthetic zone.

3. Allograft and Soft Tissue Substitute Options

The term “allograft” in soft tissue surgery is often used broadly in clinical conversation, but in practice this category includes allogenic matrices and other soft tissue substitutes such as acellular dermal matrices and collagen-based xenogeneic scaffolds. These materials are designed to reduce or eliminate the need for a palatal donor site. That is their main appeal. They shorten surgery, reduce postoperative discomfort, and make treatment of multiple sites more manageable.

These materials can perform well, and they have an important place in treatment planning, especially when patient acceptance, morbidity reduction, or limited autogenous tissue availability are major concerns. However, the literature generally supports a consistent pattern: substitutes may be clinically useful, but they do not usually match CTG for the most demanding indications involving maximal root coverage, tissue thickness gain, or long-term volumetric enhancement. Tavelli’s state-of-the-art review on extracellular matrix scaffolds framed this well by emphasizing that these materials are true alternatives, but not universal replacements, for autogenous grafts.

In other words, soft tissue substitutes are best understood as lower-morbidity options with narrower performance ceilings. They may be especially useful when the defect is moderate, the patient refuses palatal harvest, the surgical field is broad, or the clinical objective is improvement rather than absolute maximal gain.

Typical Indications for Each Procedure

When FGG Is Typically Indicated

FGG is usually indicated when the main deficiency is a lack of keratinized tissue width or an unfavorable vestibular and mucogingival relationship. This includes sites where the patient struggles with brushing because the tissue is mobile or tender, mandibular anterior teeth with minimal attached gingiva, and implant sites where the clinician wants to create a broader band of keratinized mucosa for long-term maintenance. In these situations, FGG is often preferred because it predictably increases keratinized tissue more than substitute materials.

When CTG Is Typically Indicated

CTG is usually indicated when the site needs more thickness, more volume, better root coverage, or more esthetic integration. Typical examples include single or multiple gingival recessions, thin periodontal phenotype before orthodontic or restorative treatment, soft tissue enhancement around immediate or delayed implants, buccal contour deficiency, and esthetic-zone cases where color and texture blending matter. CTG is also commonly chosen when the goal is not just more tissue, but better tissue quality and greater long-term stability.

When Allograft or Soft Tissue Substitute Materials Are Typically Indicated

Allograft and soft tissue substitute materials are usually indicated when the clinician wants to avoid a palatal donor site, when multiple adjacent areas need treatment, when the patient has limited tolerance for a second surgical site, or when the defect is appropriate for a material that can improve the site even if it may not outperform CTG. These materials are also useful for clinicians who want a less invasive option for phenotype enhancement around implants or moderate recession defects, especially in patients prioritizing comfort and recovery.

Expected Outcomes

Expected Outcome of FGG

The expected outcome of an FGG is a gain in keratinized tissue width and a more durable band of tissue that is easier for the patient to clean and less prone to discomfort during brushing. This is why FGG is still considered highly predictable for peri-implant and mucogingival sites where attached tissue is lacking. The clinician should expect some shrinkage during healing and should also expect that the final color and texture may be less esthetic than with CTG-based procedures.

Expected Outcome of CTG

The expected outcome of CTG is improved tissue thickness, better contour, stronger support for soft tissue margin stability, and, when used for recession therapy, more predictable root coverage and superior esthetic blending. This is the procedure most closely associated with premium soft tissue outcomes. The tradeoff is the donor site. CTG remains technique-sensitive and comes with greater surgical complexity and more postoperative morbidity than substitute materials.

Expected Outcome of Allograft and Substitute Materials

The expected outcome of allograft or substitute materials is meaningful soft tissue improvement with reduced morbidity. In the right indication, these materials can increase soft tissue dimensions and improve the clinical presentation of a site. However, clinicians should generally expect somewhat less gain or predictability than with autogenous CTG in the most demanding indications, especially when maximal thickness or root coverage is the objective.

How the Literature Frames the Tradeoffs

One of the strengths of the Italian soft tissue group is that their work does not oversimplify graft selection. The literature does not say that one material is “best” in every situation. It says that different grafts solve different problems. Zucchelli’s state-of-the-art review on autogenous grafting highlighted the distinct roles of FGG and CTG rather than treating them as interchangeable. Tavelli’s work on extracellular matrix scaffolds made the same point from the substitute side: these biomaterials have value, but their indications should be respected.

More recent reviews on soft tissue substitutes have reinforced this clinically useful hierarchy. When the main goal is keratinized tissue gain, FGG still appears to be more effective than substitute materials. When the main goal is soft tissue thickness and high-level esthetic integration, CTG remains the reference standard. When the clinical priority is lowering morbidity and avoiding donor tissue, substitute materials become attractive, especially for moderate deficiencies and broader treatment fields.

Around implants, long-term evidence suggests that soft tissue augmentation in general is beneficial, particularly in helping support soft tissue margin stability and peri-implant tissue health over time. But even in this setting, the choice of graft should still reflect the deficiency being treated. A site lacking keratinized mucosa is not the same problem as a site with adequate keratinized tissue but inadequate thickness.

Clinical Takeaway

The big-picture lesson in soft tissue grafting is simple: FGG is usually the procedure of choice when the goal is more keratinized tissue; CTG is usually the procedure of choice when the goal is thickness, coverage, contour, and esthetic quality; and allograft or substitute materials are typically chosen when reduced morbidity and avoidance of a donor site are priorities. The skill is not just learning how to perform each graft. The skill is learning how to match the problem to the procedure.

In modern periodontal and implant therapy, that decision has real consequences. It influences how stable the margin will be, how comfortable the site will feel to the patient, how well the tissue blends esthetically, and how maintainable the result will be over time. That is why soft tissue surgery has become such a central part of contemporary treatment planning rather than a niche subspecialty topic.